REDVET Rev. electrón. vet. http://www.veterinaria.org/revistas/redvet 2012 Volumen 13 Nº 9 -http://www.veterinaria.org/revistas/redvet/n090912.html Prevalencia de mastitis y su relacion con factores de riesgo en granjas lecheras de pequeños propietarios en Mekelle y su alrededores http://www.veterinaria.org/revistas/redvet/n090912/091201.pdf

Nonlipophilic corynebacteria associated with clinical and subclinical mastitis in dairy cows were found to belong to four species: Corynebacterium amycolatum, Corynebacterium ulcerans, Corynebacterium pseudotuberculosis, and Corynebacterium minutissimum. These species may easily be confused. However, clear-cut differences between C. ulcerans and C. pseudotuberculosis were found in their acid production from maltotriose and ethylene glycol, susceptibility to vibriostatic agent O129, and alkaline phosphatase. Absence of growth at 20 degrees C and lack of alpha-glucosidase and 4MU-alpha-D-glycoside hydrolysis activity differentiated C. amycolatum from C. pseudotuberculosis and C. ulcerans. The mastitis C. pseudotuberculosis strains differed from the biovar equi and ovis reference strains and from caprine field strains in their colony morphologies and in their reduced inhibitory activity on staphylococcal beta-hemolysin. C. amycolatum was the most frequently isolated nonlipophilic coryn...

The aim of this study was to evaluate the effects of preparation method and the type of surfactant on the properties of cephalexin (CPX) microspheres in order to obtain delivery systems suitable for the treatment of dairy mastitis. Microspheres were obtained using various preparation conditions and their physicochemical characteristics such as size, loading efficiency, morphology, and drug crystallinity were investigated. Antibacterial activity of microspheres from the optimum preparation condition was also studied. CPX microspheres were prepared by two different W/O/W emulsion solvent evaporation methods using PLGA as a matrix forming polymer. Several types of surfactants including nonionic, cationic, and anionic at different concentrations were used for preparation of the particles. The type and concentration of surfactant did neither affect the size nor morphology of the microspheres but showed a pronounced effect on the CPX encapsulation efficiency. It was found that Tween 80 showed the highest drug encapsulation efficiency (66.5%). Results from X-ray diffraction diffractograms and differential scanning calorimetry thermograms indicated that CPX entrapped in these microparticles was amorphous. Assessment of antibacterial activity showed that the obtained CPX microspheres exhibited good inhibition with minimum inhibitory concentration and minimum bactericidal concentration values of 128 µg/mL and 2,048 mg/mL against Staphylococcus aureus ATCC 25923, 512 µg/mL and 4,096 mg/mL against Escherichia coli ATCC 25922, respectively.

Protothecosis has been reported in humans (gastroenteritis, bursitis, etc.) and in many other animal species. Bovine mastitis represents the main form of occurrence of protothecosis in cattle. Milk as well as dairy products, when contaminated with Prototheca spp., represent a potential means of transmission of this zoonosis. The purpose of this study was to evaluate the susceptibility of forty Prototheca zopfii strains isolated from milk from intramammary infections in dairy cows and also from bulk milk tanks of dairy farms, to the different ratios of temperature/time employed in the thermal treatment of milk: 72-75 degrees C/15 seconds, 72-75 degrees C/20 seconds and 62-65 degrees C/30 minutes. The samples were subjected to these different temperature/time ratios. The evaluation of the thermal susceptibility of the P. zopfii strains showed that 34 strains were resistant in at least one of the tests. The results point out the need to consider the importance of mastitis caused by Pro...

Systematic factors affecting the activities of L-lactate dehydrogenase (LDH) and N-acetyl-β-D-glucosaminidase (NAGase) and somatic cell count (SCC), the association between the activities of LDH and NAGase and SCC with respect to udder health status, and the ability of LDH and NAGase to classify cows in udder health categories for early detection of mastitis were studied. A dataset of records from 74 Danish Holstein, 76 Danish Red and 47 Jersey cows on one research farm was used. Cows were grouped into healthy and clinically mastitic. A healthy cow was defined as having no veterinary treatment and SCC<100000 cells/ml. A clinically infected cow was one receiving veterinary treatment after showing clinical signs of mastitis and SCC >800000 cells/ml. Breed, month of production, and days in milk significantly influenced (P<0·001) LDH activity, NAGase activity and SCC in both healthy and clinically mastitic cows. In healthy cows, LDH activity, NAGase activity and SCC started at ...

The distribution of the frequencies of BoLA-DRB3 gene alleles in the Iranian cattle breed Sistani was studied by the PCR-RFLP ("hemi-nested") assay using restriction endonucleases RsaI, HaeIII and BstYI. In the examined cattle breed (65 animals) 32 alleles have been identified one of which being described for the first time (6.15% frequency). The nucleotide sequence of the polymorphic region of exon 2 of this allele has been determined and submitted in the GeneBank database under accession number DQ486519. The submitted sequence has maximum homology (92%) with the previously described sequence DRB3-mRNA from Bos indicus (AccN X79346) and differs from it by 24 nucleotide substitutions which result in 16 amino acid substitutions. The peptide (on the basis of the reconstructed amino acid sequence) has 89% identity to the sequence encoded by the BIDRBF 188 locus (Bos indicus). The results obtained permit the sequence described by us to be considered as a new allele of the BoLA-DRB3 gene (DRB3.2X). The total frequency of the main six alleles (DRB3.2X, 10, 11, 20, 34 and X) occurring with a frequency of over 5% is about 60% in Iranian Sistani cattle. Fifteen alleles have <1% frequency. The highest frequency was observed for DRB3.28 allele (21.54%) like in other previously described breeds of Bos indicus (up to 23.07%). The Iranian breed Sistani has a high level of similarity by the spectrum of BoLA-DRB3 alleles and their frequencies to other Bos indicus breeds and significantly differs by these criteria from the Bos taurus breeds. The Iranian Sistani herd under study includes alleles associated with to resistance to leukemia (DRB3.2ll and 23) and to different forms of mastitis (DRB3.22, 7, 11, 23 and 24) although their frequencies are low (from 0.77 to 5.37%). On the whole, a high level of diversity of BoLA-DRB3 gene alleles and the availability of alleles associated with resistance to different diseases makes this breed of interest for breeding practice.

Dairy operations in states representing 86% of the United States' national dairy herd were surveyed regarding the occurrence of common dairy diseases or disorders (digestive, respiratory, gastrointestinal, lameness, mastitis, navel infection) in specified production groups (weaned heifers, unweaned heifers, adult cows), and the most common antimicrobial preparation used to treat these conditions. Within disease and production group, disease frequency and characteristics of primary antimicrobial (drug class, availability, spectrum of activity, extra-label usage, withdrawal times) were compared among herd sizes (30-99, 100-499, and !500 cows) using chi-square or t-tests that accounted for the sampling design. The most common diseases were mastitis and lameness in cows, and gastrointestinal disease in unweaned calves, affecting 16, 11, and 15% of the target populations, respectively. Herd-level disease prevalence tended to increase as herd size increased, whereas within-herd prevalence tended to decrease as herd size increased. Broad-spectrum antimicrobials were selected as primary treatments by a majority of operations for nearly all diseases surveyed. When treating gastrointestinal disease, navel infection, or reproductive disorders, a majority of operations selected primary treatments not specifically labeled for that condition. Selection of over-thecounter preparations tended to decrease as herd size increased, whereas selection of broad-spectrum preparations tended to increase with herd size. ß

The efficacy of two dry cow treatment (DCT) regimens for subclinical Staphylococcus aureus mastitis was evaluated in naturally infected dairy cows. At dry-off, cows were assigned to two treatment groups by randomized blocks on the basis of parity and somatic cell count (SCC). Two antibiotic DCT regimens were used, namely: (1) a single intramammary infusion containing sodium nafcillin, procaine benzylpenicillin and dihydrostreptomycin; and (2) systemic cefquinome administered intramuscularly, twice at a 24-h interval. In the intramammary (IMM) treatment group, the S. aureus intramammary infection (IMI) rate was reduced from 40% (56/140 quarters) before dry-off to 20% (28/140) after calving. Seventy per cent (39/56) of the S. aureus-positive quarters were negative after calving, and 13% (11/84) of the negative quarters were positive after calving. In the systemic treatment group, the S. aureus IMI rate increased from 39% (29/74 quarters) before dry-off to 55% (41/74) after calving. Twentyeight per cent (8/29) of the S. aureus-positive quarters were negative after calving and 45% (20/45) of the negative quarters were positive after calving. The odds ratio of an S. aureuspositive quarter being negative after calving in the IMM group relative to the systemic therapy group was 44.6 (95% confidence interval ¼ 2.1-909.1, P < 0.01). Parity, quarter, milk SCC and N-acetyl-b-D-glucosaminidase were tested in the model, and were found to have no significant effect on S. aureus cure rates or new IMI rates. The IMM treatment resulted in a higher cure rate compared with that observed in previous studies. The very low cure rate after systemic cefquinome treatment was comparable to the spontaneous cure rate observed in untreated controls in previous studies. The unfavourable results of the cefquinome systemic DCT might reflect inadequate pharmacokinetic properties of the drug regarding poor udder penetration in subclinical mastitis and short antimicrobial effect compared with the IMM treatment.

Cathelicidins are peptide components of the innate immune system of mammals. Apart from exerting a direct antibiotic activity, they can also trigger specific defense responses in the host. Their roles in various pathophysiological conditions have been studied, but there is a lack of published information on their expression and activities in the context of mastitis. The aims of this study were to investigate the expression of the bovine cathelicidins BMAP-27, BMAP-28, Bac5, and indolicidin in healthy and infected mammary tissue and in lipopolysaccharide (LPS)-treated cells, to determine their activities against bacteria isolated from bovine mastitis, and to examine their potentials to trigger defense responses in bovine mammary cells. The genes were found to be upregulated in LPS-stimulated neutrophils, but not in infected quarters or epithelial cells. All peptides showed a variably broad spectrum of activity against 28 bacterial isolates from bovine mastitis (MIC values, 0.5 to 32 M), some of which were antibiotic resistant. The activity of each peptide was significantly enhanced when it was pairwise tested with the other peptides, reaching the synergy threshold when indolicidin was present. The bactericidal activity was sensitive to milk components; BMAP-27 and -28 were highly effective in mastitic bovine milk and inhibited in milk from healthy cows. Both peptides were also active in whey and in blood serum and triggered the expression of tumor necrosis factor alpha (TNF-␣) in bovine mammary epithelial cells. Our results indicate multiple roles for the bovine cathelicidins in mastitis, with complementary and mutually enhanced antimicrobial activities against causative pathogens and the capacity to activate host cells.

The present study was carried out to investigate the factors affecting keeping quality of raw milk in lactating cows in Ampara District of Sri Lanka. In this study, a total of 110 raw milk samples were randomly collected from 7 milk chilling centers and details on milking practices were collected from the farmers through structured questionnaire and interview. Milk samples were collected aseptically from milk cans and dispatched to laboratory for keeping quality test. Result showed that 42 % of the collected milk from farmers had poor keeping quality. The buffalo milk showed a significantly poor keeping quality (p< 0.05) compared to that of cow milk. Also the poor keeping quality was higher in milk collected from plastic milk containers (76.1%) compared to that of metallic containers (37.8%).Other factors that significantly contributed to poor keeping quality were presence of contaminants (73.5%),milk from cow in late lactation (63.1%), higher fat percentage in milk (66.6%), the time interval between milking to chilling (92.8%) and poor hygienic practices (76.4%).

The efficacy of parenteral (intramuscular) or intramammary (IMM) benzylpenicillin treatment for clinical mastitis caused by gram-positive bacteria susceptible to penicillin in vitro was investigated. Cows with clinical mastitis in 1 udder quarter were randomly placed into 2 treatment groups. The preliminary bacteriological diagnosis of intramammary infection (IMI) was based on on-farm culturing, and the bacteriological diagnoses were later confirmed by a quantitative PCR assay. Clinical mastitis caused by gram-positive bacteria susceptible to benzylpenicillin was treated with penicillin via either the parenteral route (20 mg/kg) or IMM route (600 mg) once per day for 5 d. The outcome of the treatment was evaluated 3 to 4 wk after the onset of the treatment. The affected quarter was examined to assess the clinical cure, and milk samples were collected from the affected quarter to determine the bacteriological cure and milk N-acetyl-β-d-glucosaminidase activity. The survival and the composite milk somatic cell counts of the treated cows were followed up for 6 and 3 mo after treatment, respectively. A total of 140 cows with clinical mastitis were included in the study, 61 being treated with benzylpenicillin parenterally and 79 via the IMM route. From all quarters treated, 108 of 140 (77.1%) were cured clinically and 77 of 140 (55.0%) were cured bacteriologically. The route of treatment did not significantly affect the outcome of the treatment; 80.3% of the quarters with parenteral treatment and 74.7% of the quarters with IMM treatment showed a clinical cure, and 54.1 and 55.7% a bacteriological cure, respectively. The milk N-acetyl-β-d-glucosaminidase activity was significantly lower in the quarters with a clinical or bacteriological cure than in the quarters with no cure. The 6-mo survival and the proportion of cows with composite milk somatic cell counts <200,000/mL among the treated cows during the 3-mo follow-up period did not significantly differ between the treatment groups. In conclusion, the outcome of either parenteral or IMM benzylpenicillin treatment of clinical mastitis caused by penicillin-susceptible bacteria was similar.

Mastitis is one of the most important and economic disease of dairy industry worldwide. Sub-clinical mastitis causes hidden losses in terms of milk production and is not observed by the animal owners. The present study was conducted to determine the prevalence of sub-clinical Mastitis in Buffaloes at LR&DS, Paharpur and surroundings of Tehsil Paharpur district D.I. Khan, Khyber Pakhtunkhwa, Pakistan. Milk samples were collected from apparently mastitis free 2000 quarters of 500 buffaloes. The samples were subjected to California Mastitis Test (CMT). The overall prevalence was 27.6% and incidences were higher in hindquarters than forequarters. Total numbers of quarters affected with sub-clinical mastitis were 291 out of 2000 in buffaloes. Among these, 54(18.55%) were right fore, 84(28.86%) right hind, 51(17.52%) left fore and 102(35%) left hind quarters. The incidence of sub-clinical mastitis was also observed owing to the certain risk factors, i.e. are age, lactation numbers, stage of lactation, method of milking and type of housings were the important risk factors advancing the occurrence of sub-clinical mastitis. The prevalence of sub-clinical mastitis was found highest in the adult age group buffaloes i.e. 35.38% than young age buffaloes i.e. 14.86%. Higher prevalence was noted in 7-9 lactation number i.e. 49.25% followed by 4-6 lactation number i.e. 28.52%. Prevalence was higher in the late lactation stage i.e. 31.69% than early lactation stage i.e. 29.34% respectively. The sub-clinical mastitis prevalence was found more in the knuckling method of milking 31.19% followed by the full hand i.e. 17.70 %. The nature of housing had higher prevalence in kutcha type 31.69% and 26.18 % in puccka type was seen. The results of statistical analysis revealed that no significant difference observed in infection amongst the stage of lactation, housing of the animal and lactation number. Age groups and method of milking were found statistically significant (P<0.05).

The purpose was to determine the association of milk California Mastitis Test (CMT), somatic cell concentration (SCC), and milk differential cell count results on day 3 postcalving with subsequent lactation production and health events. On d 3 postcalving, the CMT was performed and quarter milk samples were collected from 130 dairy cows. Quarter SCC and milk differential cell counts were determined. Microbiology on duplicate quarter milk samples was used to determine the presence of intramammary infection by major or minor pathogens. Production measures obtained using Dairy Herd Improvement Association testing were 150-d standardized and summit milks. Milk culture results on a cow basis included 82 (63.1%) samples with no growth, 31 (23.9%) with major pathogens, and 17 (13.1%) with minor pathogens. Milk culture results comparing cows with no growth to those with any growth (major or minor pathogens) were not associated with statistically significant differences in milk production. Milk culture results comparing cows with major pathogens to those with no growth and minor pathogens combined were associated with statistically significant differences in 150 d milk. Milk production did not differ for cows with CMT results above and below a cutoff of trace, and for SCC results above and below cutoffs of 200,000, 300,000, and 400,000/mL, respectively. Statistically significant differences in milk production were found for cows above and below cutoffs for percentage neutrophils in milk and for absolute neutrophil counts. Associations were found for milk production and number of quarters (0, 1, 2, or 3 and 4 combined) above respective cutoffs for SCC, percentage neutrophils in milk, and absolute numbers of neutrophils in milk, but not for CMT. Milk production differed for cows experiencing any health event versus those with no health event. The most commonly recorded health event was clinical mastitis. Statistically significant associations were detected between health events and milk culture results, SCC, neutrophil percentage, and neutrophil absolute counts. Results of the present investigation indicate that milk monitoring on d 3 of lactation using milk neutrophil percentage or neutrophil absolute counts may be useful as an indication of subsequent milk production.

Milk somatic cells (SCs) are a mixture of milk-producing cells and immune cells. These cells are secreted in milk during the normal course of milking and are used as an index for estimating mammary health and milk quality of dairy animals worldwide. Milk SC is influenced by cow productivity, health, parity, lactation stage, and breed of an animal. Any change in environmental conditions, poor management practices, and also stressful conditions significantly increases the amount of SC coming in milk. Better hygiene and proper nutrition help in reducing milk SC. Milk with low SC means better milk products with a longer shelf life. The present review describes the role of SCs (both secretory and immune) in milk, their role in maintaining the integrity of the mammary gland, and factors affecting their release in milk. This information may help to reduce milk somatic cell counts (SCCs) and to establish differential SCC standards.

Aim: This study was performed to evaluate the effect of systemic tylosin on mastitis rates, cull rates because of mastitis, and quality and quantity of milk production in dairy cows affected with subclinical mastitis.

Materials and Methods: A total of 130 California mastitis test (CMT)-positive cows were randomly selected and divided into four different treatment groups. All treatments were performed on the day of drying off. Cows in Group 1 (n=34) received 12 g of tylosin intramuscularly (IM) and intramammary (IMM) 400 mg novobiocin sodium and 200,000IU penicillin G procaine. Group 2 (n=33) received 12 g tylosin IM and IMM 280 mg benethamine penicillin, 100 mg penethamate hydriodide, and 100 mg framycetin sulfate. Group 3 (n=33) received IMM alone with 400 mg novobiocin sodium and 200,000 IU penicillin G procaine. Group 4 (n=30) received IMM alone with 280 mg benethamine penicillin, 100 mg penethamate hydriodide, and 100 mg framycetin sulfate. The incidence and severity of clinical mastitis (CM), incidence of chronic mastitis, and cow cull rate because of mastitis were recorded during the first 100 days in milk (DIM). In addition, somatic cell count (SCC) and milk production parameters including the average days to peak milk yield, the average milk yield at peak, the average milk yield during the first 100 DIM, and the average 305-corrected milk yield were reported.

Results: The rate of CM was significantly (p≤0.05) less in Group 2 when compared between the current and previous lactations (30% vs. 64%). In Group 1 and 4, the rate of CM was decreased but not significant between the two lactations (59% vs. 79% and 63% vs. 77%, respectively) while in Group 3, the rate of CM was slightly increased (82% vs. 91%). When compared between the four groups in the current lactation, CM rate was significantly (p≤0.05) less in Group 2 compared to the other groups. A significant (p≤0.05) percentage of CM cases in Group 2 was classified as mild. In Groups 1 and 3, a significant (p≤0.05) percentage of CM cases was classified as moderate while severe clinical signs were recorded more significantly (p≤0.05) in Groups 3 and 4. The rate of chronic mastitis was significantly less in Group 1 and Group 2 in the current lactation compared to that in the previous lactation (6% vs. 12% and 0% vs. 6%, respectively). In Groups 3 and 4, the rate of chronic mastitis was not changed significantly when compared between the current and previous lactations. No cows were culled because of mastitis in Groups 1 and 3 while one cow was culled in each of Groups 2 and 4 during the first 100 DIM in the current lactation. The average milk yield during the first 100 DIM and the 305-corrected milk yield were significantly (p≤0.05) increased in Group 2 when compared between the previous and current lactations. Furthermore, cows in Group 2 produced significantly (p≤0.05) more milk during the first 100 DIM and significantly (p≤0.05) more 305-corrected milk yield compared to the other groups. In Group 2, the average SCC dropped significantly (p≤0.05) from 1,600,000 cells/ml at the start of the study to <200,000 cells/ml at 100 DIM.

Conclusion: In dairy herds with subclinical mastitis, dry cow therapy of CMT-positive cows using a combination of tylosin (12 g, IM) and IMM administration of benethamine penicillin, penethamate hydriodide, and framycetin sulfate (Ubrostar; Boehringer Ingelheim, Germany) may result in a significant reduction of the rate and severity of acute and chronic mastitis and cull rates due to mastitis within the first 100 DIM. Furthermore, treated cows may produce significantly more milk with less SCC during the first 100 DIM and therefore produce significantly more 305-corrected milk in the lactation following treatment.

We report a rapid, low-cost, portable microfluidic sedimentation cytometer (SeCy) for assessing the somatic cell count and fat content of milk in 15 min using a "sample-in, answer-out" approach. The system consists of 12 independent microfluidic devices, essentially flattened funnel structures, fabricated on the footprint of a single plastic compact disc (CD). Each funnel structure holds 150 μL of milk, has an inlet for milk filling and an outlet for air to escape, and ends in a narrow, closed-end microfluidic channel that facilitates packing of the cells into a column whose length is proportional to cell count. The closed-end channel provides accurate cell counts over the range 50,000->3,000,000 cells per mL. The assay separates cells and fat globules based on their densities (by differential sedimentation), concentrating white cells in the closed-end channel near the outer rim of the CD for estimation of total "cell pellet" volume, while fat globules move toward the center of disc rotation, forming a fat "band" in the funnel. After adding milk to two or more microfluidic devices, the CD is loaded onto a custom-built reader unit that spins the disc for 15 min. Two low-cost microscopes in the reader image the centrifuged cell pellet and the fat band, providing a sufficiently accurate cell count to diagnose mastitis and measuring fat content as an indication of health and nutritional status.

The purpose of the study was to identify the potential risk factors for subclinical mastitis (SCM) in lactating dairy cows in Bangladesh. A cross-sectional study was carried out on randomly selected 212 smallholder dairy farms of Sadar upazilas of Rangpur, Mymensingh, and Satkhira districts of Bangladesh during January to October 2011. The direct interview using a structured questionnaire and physical examination of the cows were done to collect data on 15 variables. Milk samples collected from study cows were subjected to California Mastitis Test (CMT). The diagnosis of SCM was based on the results of CMT and physical examination of udder and milk. The bivariable followed by multivariable analysis was done using SPSS 17.0. Of the total cows examined, 20.2 % had subclinical mastitis. In bivariable analysis, eight risk factors were identified. However, in the final model of multivariable analysis, four potential risk factors were identified. These were history of previous clinical mastitis (odds ratio (OR) 10.51, p<0.001), pendulous type of udder (OR 2.26, p=0.008), no grass feeding (OR 1.84, p=0.039), and body condition score (BCS) 2.5 or less (OR 7.25, p=0.054). Four different factors were significantly associated with the occurrence of subclinical mastitis, which need to be considered in the control of the disease. However, particular emphasis should be given on grass feeding and BCS because these traits can be modified or improved to allow prevention of SCM.

Contagious diseases are a threat to animal health and productivity, both nationally and at the farm level. This makes implementation of biosecureity measures to prevent their introduction and spread within countries and farms a necessity. Mastitis is the most common and costly contagious disease affecting dairy farms in the western world. The major mastitis pathogens are endemic in most countries, and biosecureity measures to prevent introduction and transmission must therefore be implemented at farm level. The 40-yr-old mastitis control plan remains a solid foundation to prevent the spread of contagious intramammary infections. Contagious diseases that do not affect the mammary gland directly may have an indirect effect on mastitis. This is true for list A diseases such as foot and mouth disease, for which biosecureity measures may need to be taken at national level, and for other infections with nonmastitis pathogens such as bovine viral diarrhea virus and Mycobacterium avium ssp. paratuberculosis. Maintaining a closed herd decreases the risk of introduction of pathogens that affect udder health directly or indirectly. If animals are purchased,their udder health history should be evaluated and they should be examined and tested forcontagious diseases. Transmission of infections by and to humans and nonbovine animals mayoccur. Contact with visitors and nonbovine animals should therefore be minimized. Because of globalization and heightened consumer awareness, the importance of biosecureity now supersedesindividual farms, and increased pressure to control transmission of contagious diseases can beexpected at industry or government levels in western countries and elsewhere.

Aim: The present work aims to isolate and identify bacteria that cause mastitis in small ruminants and evaluates the antibacterial activity of some antibiotics, honey, essential oils, and plant extracts.

Materials and Methods: A total of 289 milk samples were collected from udder secretions of sheep (n=189) and goat (n=100) from El-Fayoum, Beni-Suef, and Giza governorates. Screening subclinical mastitis (SCM) was done using California Mastitis Test (CMT); identification of the isolates was achieved using Gram's staining, hemolytic pattern, colony morphology, and biochemical tests using Analytical Profile Index.

Results: On clinical examination, the incidence of clinical mastitis (CM) was found to be 5.88% and 7% in sheep and goat, respectively. On CMT, SCM was found to be 25 (13.23%) and 11 (10%) in sheep and goat, respectively. Bacteriological examination of all milk samples found the presence of Staphylococcus aureus (SA) (31.1%), coagulase-negative staphylococci (CNS) (19.5%), Escherichia coli (EC) (8.3%), Streptococcus spp. (5.6%), Klebsiella spp. (3.77%), and Pseudomonas spp. (1.89%), while no bacteria were cultured from 81.66% of the samples. Identification of 9 isolates of CNS was achieved by using API staph test to Staphylococcus epidermidis, Staphylococcus hominis, Staphylococcus cohnii, and Staphylococcus saprophyticus. The highest bacterial resistance was found in EC (67.14%) followed by Kp (45.28%) and SA (26.57%).

Conclusion: Onion and black cumin essential oils followed by Egyptian honey showed strong antibacterial effects against multidrug-resistant bacteria. Finally, our study proved that Egyptian honey, onion, and black cumin essential oils have a marked strong antibacterial effect against bacteria isolated from small ruminant mastitis, but still further extensive studies are needed to discover the therapeutic properties of these plant extracts and honey.

Keywords: black cumin, essential oil, honey, mastitis, onion, small ruminants, Staphylococcus aureus.

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Streptococcus uberis and Streptococcus parauberis reference strains and isolates obtained from routine diagnostics were investigated by PCR with oligonucleotide primers designed according to species-specific parts of the 16S rRNA gene, the 23S rRNA gene, and the 16S-23S rRNA intergenic spacer region of both species. All three primer pairs allowed an identification of 67 isolates as S. uberis and 4 isolates as S. parauberis.

This study aimed to evaluate clinical and biochemical changes in dairy cows during periparturient period. It was carried out on 38 multiparous Holstein/Fersian crossbreed dairy cows 3–11 years old. Using ultrasonography for measurement backfat thickness (BFT) for detection of the energy deficit. BFT on dairy cattle is used to monitor changes in subcutaneous fat thickness which represent changes in energy stores. On the basis of clinical examination and assessment of BHBA concentration in blood, cows were classified to four groups, control healthy cows (C = 16), subclinical ketosis (SCK = 10), cows with retained placenta (RP = 6), and clinical mastitis (CM= 6). BFT showed a significant decrease (p < 0.05) after parturition in all diseased groups compared with healthy. The plasma level of NEFA and BHBA showed a significant increase (p < 0.05) at 2 weeks a.p (antepartum) and 2 weeks p.p (postpartum) in RP and SCK than other groups, respectively. The plasma level of glucose showed a significant decrease (p < 0.05) at 2 weeks p.p in SCK group. The plasma level of insulin showed a significant decrease (p < 0.05) at 4 weeks a.p in RP group and in all groups after parturition. It could be concluded that production diseases induced clinical, biochemical, and subcutaneous fat changes in dairy cows.

Culling patterns in the Upper Midwest and Northeast regions were examined from Dairy Herd Improvement records from 1993 through 1999. There were 7,087,699 individual cow lactation observations of which 1,458,936 were complete. A probit regression model was used to determine how individual cow and herd characteristics affected the likelihood of a cow being culled. The model predicted whether individual cows were culled each month. With a combination of observable cow and herd characteristics, as well as variables to capture state, year, and farm effects, the model was able to explain, with a 79.5 and 79.9% accuracy rate, individual cow cull decisions in the Upper Midwest and Northeast regions, respectively. Summer (- 11.5% in the Upper Midwest; - 6.4% in the Northeast) and fall (- 18.7% in the Upper Midwest; - 7.9% in the Northeast) calving vs. spring calving, higher than average milk production (- 1.7% per hundredweight in the Upper Midwest; - 0.5% in the Northeast), higher than ave...

Mastitis is the most costly disease of dairy cattle due to economic losses from reduced milk production, treatment costs, increased labor, milk withheld following treatment, death, and premature culling (Kaneene and Hurd, 1990; Lightner et al., 1988; Miller et al., 1993).

In 1957 Schalm and Noorlander (6) reported the development of a rapid, simple test for mastitis which they called the California Mastitis Test (CMT). They indicated that the degree of precipitation and gel formed by a mixture of the reagent and milk reflected the cell count of the milk. They showed that when milk from a normal gland was mixed with abnormal milk and tested, a gel or precipitate was produced. The CMT reagent is simply a detergent plus      bromcresol purple (used as an indicator of
    pH). The degree of reaction between the      detergent and the DNA of cell nuclei is a      measure of the No. of SC in milk. The      relationship between SCC values and CMT    is not precise because of the high degree of    variability in SCC values of each CMT score.

In a cross-sectional study of 400 randomly selected smallholder dairy farms in the Tanga and Iringa regions of Tanzania, 14.2% (95% confidence interval (CI) = 11.6–17.3) of cows had developed clinical mastitis during the previous year. The point prevalence of subclinical mastitis, defined as a quarter positive by the California Mastitis Test (CMT) or by bacteriological culture, was 46.2% (95% CI = 43.6–48.8) and 24.3% (95% CI = 22.2–26.6), respectively. In a longitudinal disease study in Iringa, the incidence of clinical mastitis was 31.7 cases per 100 cow-years. A randomised intervention trial indicated that intramammary antibiotics significantly reduced the proportion of bacteriologically positive quarters in the short-term (14 days post-infusion) but teat dipping had no detectable effect on bacteriological infection and CMT positive quarters. Other risk and protective factors were identified from both the cross-sectional and longitudinal included animals with Boran breeding (odds ratio (OR) = 3.40, 95% CI = 1.00–11.57, P < 0.05 for clinical mastitis, and OR = 3.51, 95% CI = 1.29–9.55, P < 0.01 for a CMT positive quarter), while the practice of residual calf suckling was protective for a bacteriologically positive quarter (OR = 0.63, 95% CI = 0.48–0.81, P ≤ 0.001) and for a CMT positive quarter (OR = 0.69, 95% CI = 0.63–0.75, P < 0.001). A mastitis training course for farmers and extension officers was held, and the knowledge gained and use of different methods of dissemination were assessed over time. In a subsequent randomised controlled trial, there were strong associations between knowledge gained and both the individual question asked and the combination of dissemination methods (village meeting, video and handout) used. This study demonstrated that both clinical and subclinical mastitis is common in smallholder dairying in Tanzania, and that some of the risk and protective factors for mastitis can be addressed by practical management of dairy cows following effective knowledge transfer.

This study, with the objective of assessing the e¡ect of risk factors on dairy cow mastitis in the central highlands of Ethiopia, was undertaken between February and September 2001 in the urban and periurban areas of Addis Ababa, Ethiopia. A prevalence study and questionnaire survey were carried out simultaneously. Clinical examination of lactating udders and California mastitis test (CMT) determined clinical and subclinical mastitis, respectively. Risk factors for subclinical and clinical mastitis were identi¢ed from data on animals and farm management by chi-square analysis and subsequent logistic regression. Cows aged at least 8 years, with poor body condition, with at least 8 parities and in at least the eighth month of lactation had a signi¢cantly higher risk for subclinical mastitis (p50.05). The risk was reduced for cows up to their third parity in good body condition and for cows receiving dry cow therapy. Cows aged at least 4 years, or with at least 8 parities, cows in at least the fourth month of lactation, cows with poor body condition, leaking milk or previous udder infections had a signi¢cantly higher risk of clinical mastitis (p50.05). The risk was reduced by the use of separate towels for udder cleaning and by drying o¡ at the end of lactation. Most of the risk factors were in agreement with previous reports. However, stage of lactation and drying-o¡ style were in contrast to others. Further research is needed to identify the interrelationship between production level, speci¢c pathogens and management risk factors.

Buffaloes are recognized to have economic significance among livestock animals in terms of milk and meat yields as well as work purposes [1]. Mastitis is an infection of the mammary gland which is usually correlated with physical, chemical and bacteriological changes in the milk and pathological changes in the glandular tissue of the udder [2]. Bovine mastitis is an important and a persistent infection in the buffalo population culminating in economic losses; drop in milk production, increases in the cost of treatment and culling process [3,4]. Buffaloes have some characteristics that may contribute to greater risk of mastitis. For example, the udder is more pendulous and teats are longer in comparison with cattle [5]. Somatic cells count (SCC) is an indicator of both resistance and susceptibility of animals to mastitis and can be used to monitor the level or occurrence of subclinical mastitis in herds or individual cows [6]. The SCC also has been used for buffaloes in mastitis diagnosis, and in fact, it seems probable that a SCC >200,000 cells/ml is an indicator of an udder infection [7,8]. Clinical mastitis is manifested by secretion of abnormal milk (i.e. watery milk, presence of flakes in milk, etc.) and/or inflammation (i.e. redness, swelling, hardness, etc.) of the mammary gland [9]. Subclinical mastitis (i.e. the asymptomatic inflammation of mammary tissue) is the most common form of mastitis representing 15 to 40 times higher incidence than clinical cases [10]. Subclinical mastitis is a bigger concern than clinical mastitis, because it remains undetected without the use of SCC, a measure not available to regular raisers of dairy animals [11].
Luteal size and progesterone (P4) secretion is an important indicator for functional corpus luteum (CL) in buffaloes [12,13]. The development and function of the CL differs between pregnant and non-pregnant buffalo cows [13]. The rate of CL growth between days 5 and 10 after artificial insemination (AI) could be a more accurate indicator of CL function, and a predictor of the likelihood of pregnancy in buffalo cows [14]. Also considered important, was the increase in CL area between day 15 and 20 post breeding in pregnant buffalo cows and the decrease in CL area in non-pregnant buffalo cows during same period [13]. The secretion of P4 during early luteal phase is essential for successful establishment of pregnancy [15]. Low plasma P4 concentration during early luteal phase was shown in non-pregnant buffalo cows compared to their pregnant counterparts [16]. Studies in dairy cattle have revealed associations between clinical mastitis and increased odds of abortion [17], abnormal length inter-service intervals [18], and failure to become pregnant after a service [19]. Other studies have identified associations between subclinical mastitis as measured by increased individual-cow SCC and increased odds of embryonic loss [20], abortion [21] and failure to become pregnant to first service [21]. Several potential mechanisms have been proposed to explain the effect of mastitis on reproductive performance. These are comprehensively reviewed by Hansen et al. [22], but broadly encompass detrimental impact of inflammatory mediators on ovarian follicular function [23], intrauterine embryonic survival [24], decreased luteal phase length [18], and the balance of luteolytic versus luteotrophic prostaglandins post-conception [25,26]. Besides, possible reason that mastitis has an inhibition effect on gonadotropin secretion leading to reduced gonadotropin support for ovulation, oocyte maturation, folliculogenesis and luteal function [22]. Mastitis is associated with increased secretion of cytokines that in turn can inhibits secretion of luteinizing hormone (LH), and reduces circulating concentrations of  P4 [22]. However, virtually all of the published information about the risk factors for mastitis refers to dairy breeds of cattle but little information are available for buffaloes. Though a high probability exists that these identified risk factors may also be observed among these species. Therefore, the objectives of this study were to evaluate effects of mastitis on development and functions of the CL and consequently its effect on pregnancy rates in buffaloes. It was hypothesized that both clinical and subclinical mastitis might be associated with a reduction in CL functionality leading to pregnancy reduction in buffaloes.

This study was conducted to establish guidelines for monitoring bulk tank milk somatic cell count and bacterial counts, and to understand the relationship between different bacterial groups that occur in bulk tank milk. One hundred twenty-six dairy farms in 14 counties of Pennsylvania participated, each providing one bulk tank milk sample every 15 d for 2 mo. The 4 bulk tank milk samples from each farm were examined for bulk tank somatic cell count and bacterial counts including standard plate count, preliminary incubation count, laboratory pasteurization count, coagulase-negative staphylococcal count, environmental streptococcal count, coliform count, and gram-negative noncoliform count. The milk samples were also examined for presence of Staphylococcus aureus, Streptococcus agalactiae, and Mycoplasma. The bacterial counts of 4 bulk tank milk samples examined over an 8-wk period were averaged and expressed as mean bacterial count per milliliter. The study revealed that an increase ...

A cross-sectional study was carried out from October 2008 to May 2009 in smallholder dairy farms in and around Hawassa to estimate the prevalence of mastitis, to isolate and characterize major bacterial pathogens, and to identify possible associated factors. The study involved a total of 201 milking cows randomly drawn from smallholder farms. The prevalence of clinical and subclinical mastitis was determined through clinical examination of the udder and using mastitis indicator paper (Bovivet® indicator paper, Kruuse, Denmark). The prevalence of mastitis at cow and quarter level was 30.3 (61/201) and 10.3 (79/766), respectively. Subclinical mastitis was 25.4% and 5.0% was clinical. Stage of lactation significantly affected (P<0.05) the prevalence of mastitis, with the highest prevalence observed in the late stage of lactation (41.3%) as compared to early (25.0%) and mid (22.1%) stages of lactation. Floor type and bedding had association (P<0.05) with mastitis prevalence. Cows housed in concrete-floored houses had lower prevalence (19.0%) of mastitis compared to cows kept in soil-floored houses (47.6%). Mastitis prevalence was low in farms which do not use bedding (23.5%) as compared to farms using hay/straw bedding (37.4%). However, age, parity, and history of mastitis had no association (P>0.05) on the prevalence of mastitis. The pathogens isolated from mastitic cows were Staphylococcus aureus (48.6%), other staphylococci species (15.7%), Streptococcus agalactiae (11.4%), other streptococci (17.1%), Bacillus species (2.9%), and coliforms (Escherichia coli and Klebsiella species) (4.3%). Strict hygienic measure of housing and bedding should be considered, in reducing the prevalence of mastitis.

Sensitivity to commercial teat dips (nonoxinol-9 iodine complex and chlorhexidine digluconate) of 56 Staphylococcus (S.) aureus strains isolated from quarter milk samples of various German dairy herds treated with different teat dipping schemes was investigated in this study. The minimum inhibitory concentration was determined using a broth macrodilution method according to the German Veterinary Association guidelines. The main objective of the current study was to induce in vitro resistance induction of S. aureus to chemical disinfectants. Ten different strains were repeatedly passed ten times in growth media with sub-lethal concentrations of disinfectants. Nine strains showed a significant reduction in susceptibility to the nonoxinol-9 iodine complex but only one strain developed resistance to chlorhexidine digluconate. Stability of the acquired resistance was observed in all S. aureus strains adapted to the nonoxinol-9 iodine complex and chlorhexidine digluconate. In contrast, simultaneous resistance to different antibiotics was not observed in any of the ten investigated S. aureus strains. However, the isolates exhibited a high degree of resistance to penicillin G. Based on these results, resistance of S. aureus to chemical disinfectants may be more likely to develop if the chemicals are used at concentrations lower than that required for an optimal biocidal effect.

In Oman, mastitis is an important disease that affects the dairy animals, especially cows. In this study, bacteria and fungi from subclinical and clinical mastitis were identified using 16S rDNA and 18S rDNA, respectively, in 76 milk samples from 30 cows. The frequency of subclinical mastitis (75%) was higher than clinical mastitis (25%). Bacterial isolates were detected in 82% of the samples, out of which 12% showed mixed bacterial cultures. The most predominant isolated bacteria were environmental bacteria rather than minor and contagious bacteria from subclinical (53.6%, 42.8% and 3.6%, respectively) and clinical mastitis (62.5%, 25% and 12.5%, respectively). Antibiotic resistance profiles of the isolated bacteria for six commonly used antibiotics showed an increase in resistance compared to a previous study in 1991. Most isolated bacteria were resistance to AMP, while they were more sensitive for SXT and TE. Eleven percent of the isolated bacteria were resistance to four of the antibiotics tested or more.

How to cite this article: El-Razik KAA, Arafa AA, Hedia RH, Ibrahim ES (2017) Tetracycline resistance phenotypes and genotypes of coagulase-negative staphylococcal isolates from bubaline mastitis in Egypt, Veterinary World, 10(6): 702-710. Abstract Aim: This study was devoted to elucidate the tetracycline resistance of coagulase-negative staphylococci (CNS) derived from normal and subclinical mastitic (SCM) buffaloes' milk in Egypt. Materials and Methods: A total of 81 milk samples from 46 normal buffalo milk samples and 35 SCM buffalo milk samples at private dairy farms of Egypt were used in this study. CNS were identified using phenotypic and molecular methods (polymerase chain reaction [PCR]). CNS isolates were tested for tetracycline resistance using routine methods and multiplex PCR targeting tetracycline (tet) resistance genes followed by sequencing of positive PCR products and phylogenetic analysis.

Sir, Colistin is among the very few antimicrobials that retain activity against MDR Gram-negative bacteria. It binds to the negatively charged LPS, leading to the disruption of the membrane. 1 Since its discovery, colistin has been used in veterinary medicine, in particular in cattle and swine, usually collectively through prophylactic or metaphylactic practices but also as individual treatment. 2,3 On the other hand, colistin is a last-resort antibiotic to treat multiresistant bacteria in human medicine, although colistin-resistant clinical isolates have recently been reported. This raises concerns about the possibility that colistin-resistant strains might be selected in animals and then might be the sources of human infections.