The Efficacy of the Microscopic Examination of the Incubated Producer Milk Samples in Detecting Streptococcic Mastitis in Dairy Herds

1946 ◽  
Vol 9 (4) ◽  
pp. 197-248
Author(s):  
H. P. Johnson ◽  
C. S. Bryan
Keyword(s):  
Microscopic Examination ◽  
Dairy Herds ◽  
Milk Samples

scholarly journals Prevalence of methicillin-resistant Staphylococcus aureus and pattern of antimicrobial resistance in mastitis milk of cattle in Chitwan, Nepal

2021 ◽  
Vol 17 (1) ◽  
Author(s):  
Asmita Shrestha ◽  
Rebanta Kumar Bhattarai ◽  
Himal Luitel ◽  
Surendra Karki ◽  
Hom Bahadur Basnet
Keyword(s):  
Public Health ◽  
Staphylococcus Aureus ◽  
Antimicrobial Resistance ◽  
Subclinical Mastitis ◽  
World Health ◽  
Dairy Herds ◽  
Microbiological Analysis ◽  
Biochemical Tests ◽  
Methicillin Resistant ◽  
Milk Samples

Abstract Background The threat of methicillin-resistant Staphylococcus aureus (MRSA) exists globally and has been listed as a priority pathogen by the World Health Organization. One of the sources of MRSA emergence is livestock and its products, often raised in poor husbandry conditions. There are limited studies in Nepal to understand the prevalence of MRSA in dairy animals and its antimicrobial resistance (AMR) profile. A cross-sectional study was conducted in Chitwan, one of the major milk-producing districts of Nepal, from February 2018 to September 2019 to estimate the prevalence of MRSA in milk samples and its AMR profile. The collected milk samples (n = 460) were screened using the California Mastitis Test (CMT) and positive samples were subjected to microbiological analysis to isolate and identify S. aureus. Polymerase Chain Reaction (PCR) was used to identify the presence of the mecA gene and screen for MRSA. Results In total, 41.5% (191/460) of milk samples were positive in the CMT test. Out of 191 CMT positive milk samples, the biochemical tests showed that the prevalence of S. aureus was 15.2% (29/191). Among the 29 S. aureus isolates, 6.9% (2/29) were identified as MRSA based on the detection of a mecA gene. This indicates that that 1.05% (2/191) of mastitis milk samples had MRSA. The antibiotic sensitivity test showed that 75.9% (22/29) and 48.3% (14/29) S. aureus isolates were found to be sensitive to Cefazolin and Tetracycline respectively (48.3%), whereas 100% of the isolates were resistant to Ampicillin. In total 96.6% (28/29) of S. aureus isolates were multidrug-resistant (MDR). Conclusions This study revealed a high prevalence of S. aureus-mediated subclinical mastitis in dairy herds in Chitwan, Nepal, with a small proportion of it being MRSA carrying a mecA gene. This S. aureus, CoNS, and MRSA contaminated milk poses a public health risk due to the presence of a phenotype that is resistant to very commonly used antibiotics. It is suggested that dairy herds be screened for subclinical mastitis and treatments for the animals be based on antibiotic susceptibility tests to reduce the prevalence of AMR. Furthermore, future studies should focus on the Staphylococcus spp. to explore the antibiotic resistance genes in addition to the mecA gene to ensure public health.

scholarly journals RELATIONSHIP BETWEEN BLOOD METABOLIC PROFILES AND MILK YIELD ASSOCIATED WITH PARITY AND STAGE OF LACTATION IN CROSSBRED DAIRY COWS IN BANGLADESH

2019 ◽  
Vol 1 (2) ◽  
Author(s):  
L Naher ◽  
M. A. Samad ◽  
S. H. M. F. Siddiki ◽  
M. T. Islam
Keyword(s):  
Dairy Cows ◽  
Milk Yield ◽  
Metabolic Profile ◽  
Transition Period ◽  
Dairy Herds ◽  
Metabolic Profiles ◽  
Milk Samples ◽  
Stage Of Lactation ◽  
Lactating Dairy Cows ◽  
Calcium Phosphorus

Background: Cattle cross-breeding program has been launched throughout Bangladesh but this program has still focused mainly on biological rather than economic evaluation. Currently, 30000 dairy farms with mainly cross-bred cows are in operation throughout the country and this intensive dairy farming system with high milk yielding dairy cows is supposed to be associated with high incidence of sub-clinical nutritional and metabolic diseases. Objectives: The objective of this study was to detect the relationship between major blood metabolic profiles and milk yield associated with parity and stage of lactation in cross-bred dairy cows. Materials and Methods: Blood samples of 220 apparently healthy lactating cross-bred dairy cows (HF x L, n = 190; SH x L, n = 20 and JS x L, n = 10) of 10 dairy herds were collected for metabolic profile test (MPT) in Bangladesh during the period from July to November 2016. The major metabolic profiles which are associated with milk fever (calcium, phosphorus & magnesium) and ketosis (glucose) were considered in this study. These biochemical parameters were estimated to detect the influence of risk factors including herds, breeds, parities and lactation age of cross-bred lactating dairy cows by using the commercial kits in spectrophotometer method. Results: The evaluation of the biochemical constituents of 220 cross-bred lactating dairy cows revealed that 30% (n = 66) had hypocalcaemia and 20.45% (n = 45) had hypoglycemia. Significantly lower levels of average calcium (7.93 ± 0.36 mg/dl; p < 0.024) and glucose (43.44 ± 3.63 mg/dl; p < 0.0001) values were recorded in HF x L cross-bred dairy herd of BAUDF, Mymensingh in comparison to other investigated nine dairy herds. The highest milk yield was recorded at 7th parity (16 +- 0.91 liter / day) and 1st week of lactation (17.33 +- 1.09 liter / day) were associated with low mean calcium (8.09 +- 0.85 mg / dl; 6.68 +- 0.13 mg/dl) and glucose (36.45 +- 7.67 mg/dl; 32.31 +- 3.90 mg / dl) levels in comparison to the respective values of different parity and lactation weeks. Conclusions: A relationship between blood metabolic profiles and milk yield associated with herd, breed, parity and lactation stages was recorded in lactating crossbred dairy cows. The evaluation of blood metabolites at different stages of lactation cycle especially at transition period is required to detect the nutritional and metabolic health for optimum milk production and to achieve maximum reproductive potential of high yielding dairy cattle. The readily available milk samples could be used as a biological fluid to monitor the health and nutritional status of dairy cows by using mid-infrared (MIR) spectroscopy method to prevent sub-clinical metabolic disorders. Therefore, well developed laboratories with necessary equipment, test kits and reagent should be provided to perform MPT in both the blood and milk samples for practical uses. Keywords: Compton metabolic profile test, Metabolic profile, Lactating cross-bred cows, Calcium, Phosphorus, Magnesium, Glucose, Parity, Lactation stages

Characterisation ofStaphylococcus aureusstrains isolated from mastitis bovine milk in Argentina

2018 ◽  
Vol 85 (1) ◽  
pp. 57-63 ◽  
Author(s):  
Mariela E Srednik ◽  
Valentine Usongo ◽  
Sarah Lépine ◽  
Xavier Janvier ◽  
Marie Archambault ◽  
...  
Keyword(s):  
Large Scale ◽  
Susceptibility Testing ◽  
Restriction Analysis ◽  
Bovine Milk ◽  
Dairy Herds ◽  
Antibiotic Susceptibility Testing ◽  
Chromosomal Dna ◽  
Isolation Rate ◽  
Milk Samples ◽  
Mastitic Milk

The study reported in this Research Communication was conducted to characteriseStaphylococcus aureusisolates recovered from mastitic bovine milk from dairy herds in Argentina. A total of 829 mastitic milk samples, both clinical and subclinical, were collected from 21 farms by veterinarians and submitted to the laboratory for testing from which 229S. aureusisolates were recovered, an isolation rate of 28·1%. These isolates were tested for susceptibility to the antibiotics penicillin, erythromycin and clindamycin. Of the 229 isolates, 53 (23·1%) were resistant to penicillin, 31 (13·5%) to erythromycin and 28 (12·2%) to clindamycin. All isolates were negative for themecA,mecC andpvlgenes by PCR. Southernblot hybridisation revealed that theermC gene was located on plasmid bands. Eighty isolates were randomly selected from the 229 for further characterisation. Restriction analysis of chromosomal DNA with Cf9I followed by PFGE of the 80 isolates revealed 23 distinct pulsotypes at 80% similarity. Seven major types (A, B, N, P, S, T, U and V) accounted for 68·7% of these isolates and 12 pulsotypes (A, B, F, G, J, K, M, N, P, S, T and U) occurred on more than one farm indicating genetic diversity within the farms. MLST of a representative isolate from dominant types identified the STs 97 705, 746, 2102 and 2187 with ST97 being the most predominant. Antibiotic susceptibility testing showed that 53·7% of the 80 randomly selected isolates were resistant to at least one of the three antibiotics tested. To our knowledge, this study represents the first large scale molecular studies onS. aureusisolates from dairy farms in Argentina.

scholarly journals Identification of subclinical mastitis caused by Mycoplasma spp. from screenings of bulk tanks

2018 ◽  
Vol 70 (6) ◽  
pp. 1793-1797
Author(s):  
S.F. Joaquim ◽  
F.F. Guimarães ◽  
A. Salina ◽  
N.B. Junqueira ◽  
E.N. Gomes ◽  
...  
Keyword(s):  
Polymerase Chain Reaction ◽  
Subclinical Mastitis ◽  
Mammary Glands ◽  
Dairy Herds ◽  
Mycoplasma Bovis ◽  
Chain Reaction ◽  
Milk Samples ◽  
Polymerase Chain ◽  
Bulk Tank ◽  
Mycoplasma Spp

ABSTRACT Mastitis caused by Mycoplasma spp., regardless of species, are considered highly contagious pathogens and, usually was not responsive to antimicrobial therapy. Five dairy herds, comprising 489 animals and 1,956 mammary glands, were used in this study. Milk samples were obtained from bulk tanks and subjected to polymerase chain reaction (PCR) for the identification of Mollicutes, Mycoplasma spp., and Mycoplasma bovis. Moreover, individual samples from cases of clinical and subclinical mastitis in quarters of the dairy herds’ animals that yielded a positive PCR upon bulk tank analysis were subjected to molecular analysis. Only one bulk tank was positive for class Mollicutes by PCR. All positive samples classified as mastitis teats had their DNA extracted and tested by PCR for both class Mollicutes and M. bovis. Of these, two (2.08%) were positive for Mycoplasma genus, although none was positive for M. bovis. This result suggests that the PCR of bulk tanks is a viable tool in monitoring and preventing mastitis infections caused by Mycoplasma spp.

scholarly journals Surveillance of Antibiotic Resistance of Maltose-Negative Staphylococcus aureus in South African Dairy Herds

Antibiotics ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 616
Author(s):  
Joanne Karzis ◽  
Inge-Marié Petzer ◽  
Edward F. Donkin ◽  
Vinny Naidoo ◽  
Eric M.C. Etter
Keyword(s):  
Staphylococcus Aureus ◽  
Antibiotic Resistance ◽  
South African ◽  
Inhibitory Concentration ◽  
Aureus Strain ◽  
Diffusion Method ◽  
Dairy Herds ◽  
Disk Diffusion Method ◽  
Data Set ◽  
Milk Samples

Antibiotic resistance has been reported since the 1940s in both human and veterinary medicine. Many years of monitoring milk samples in South Africa led to identification of a novel maltose-negative Staphylococcus aureus (S. aureus) strain, which appears to be an emerging pathogen. In this study, the susceptibility of this strain to antibiotics was evaluated over time, during diverse seasons in various provinces and according to somatic cell count (SCC) categories. A data set of 271 maltose-negative S. aureus isolates, from milk samples of 117 dairy herds, was examined using the disk diffusion method, between 2010 and 2017. This study also compared the susceptibility testing of 57 maltose-negative and 57 maltose-positive S. aureus isolated from 38 farms, from three provinces using minimum inhibitory concentration (MIC). The MIC results for the maltose-negative S. aureus isolates showed highest resistance to ampicillin (100%) and penicillin (47.4) and lowest resistance (1.8%) to azithromycin, ciprofloxacin and erythromycin. The maltose-negative S. aureus isolates showed overall significantly increased antibiotic resistance compared to the maltose-positive strains, as well as multidrug resistance. Producers and veterinarians should consider probability of cure of such organisms (seemingly non-chronic) when adapting management and treatment, preventing unnecessary culling.

Effect of coagulase-negative staphylococci on somatic cell count in Dutch dairy herds

2010 ◽  
Vol 77 (3) ◽  
pp. 318-324 ◽  
Author(s):  
Otlis Sampimon ◽  
Bart HP van den Borne ◽  
Inge Santman-Berends ◽  
Herman W Barkema ◽  
Theo Lam
Keyword(s):  
Somatic Cell ◽  
Cell Count ◽  
Somatic Cell Count ◽  
Health Management ◽  
Dairy Farms ◽  
Subclinical Mastitis ◽  
Dairy Herds ◽  
Coagulase Negative Staphylococci ◽  
Intramammary Infections ◽  
Milk Samples

The effect was quantified of coagulase-negative staphylococci (CNS) intramammary infections on quarter- and cow-level somatic cell count (SCC) and on bulk milk somatic cell count (BMSCC) in different BMSCC cohorts in Dutch dairy herds. Two datasets were used for this purpose. In the first dataset, on 49 randomly selected dairy farms a total of 4220 quarter milk samples of 1072 cows were collected of all cows and heifers with a test-day SCC ⩾250 000 and ⩾150 000 cells/ml, respectively, and of 25% of cows and heifers below these thresholds. In the second dataset, on 39 selected dairy farms a total of 8329 quarter milk samples of 2115 cows were collected of all cows with a test-day SCC ⩾250 000 cells/ml following two consecutive SCC <250 000 cells/ml, and of heifers using the same SCC criteria but with a threshold of 150 000 cells/ml. These cows and heifers were defined as new high SCC. In both datasets, CNS was the most frequently isolated pathogen, 11% in the first dataset and 12% in the second dataset. In both datasets, quarters with CNS IMI had a lower SCC than quarters infected with major pathogens, and a higher SCC than culture-negative quarters. The same was found for SCC at cow level. Coagulase-negative staphylococci were more often found in quarters with SCC ⩾200 000 cells/ml in dairy farms with a BMSCC <150 000 cells/ml compared with dairy farms with a higher BMSCC. Prevalence of CNS in cows and heifers with a high SCC was higher in dairy farms with a BMSCC <150 000 cells/ml compared with dairy farms with a medium or high BMSCC: 30, 19 and 18%, respectively. This indicates that CNS IMI as a cause of subclinical mastitis is relatively more important in dairy farms with a low BMSCC and may become a point of attention in udder health management on that type of farm.

Using milk leukocyte differentials for diagnosis of subclinical bovine mastitis

2017 ◽  
Vol 84 (3) ◽  
pp. 309-317 ◽  
Author(s):  
Juliano Leonel Gonçalves ◽  
Roberta L. Lyman ◽  
Mitchell Hockett ◽  
Rudy Rodriguez ◽  
Marcos Veiga dos Santos ◽  
...  
Keyword(s):  
Bovine Mastitis ◽  
Dairy Herd ◽  
Inflammatory Cells ◽  
Subclinical Mastitis ◽  
Absolute Number ◽  
Dairy Herds ◽  
Milk Samples ◽  
Lactating Cows ◽  
Automated Instrument ◽  
Culture Positive

This research study aimed to evaluate the use of the milk leukocyte differential (MLD) to: (a) identify quarter milks that are culture-positive; and (b) characterize the milk leukocyte responses to specific groups of pathogens causing subclinical mastitis. The MLD measures the absolute number and relative percentage of inflammatory cells in milk samples. Using the MLD in two dairy herds (170 and 172 lactating cows, respectively), we studied all lactating cows with a most recent monthly Dairy Herd Improvement Association somatic cell count (SCC) >200 × 103 cells/ml. Quarter milk samples from 78 cows meeting study criteria were analysed by MLD and aseptically collected milk samples were subjected to microbiological culture (MC). Based upon automated instrument evaluation of the number and percentage of inflammatory cells in milk, samples were designated as either MLD-positive or – negative for subclinicial mastitis. Positive MC were obtained from 102/156 (65·4%) of MLD-positive milk samples, and 28/135 (20·7%) of MLD-negative milk samples were MC-positive. When MC was considered the gold standard for mastitis diagnosis, the calculated diagnostic Se of the MLD was 65·4% (IC95% = 57·4 to 72·8%) and the Sp was 79·3% (IC95% = 71·4 to 85·7%). Quarter milks positive on MC had higher absolute numbers of neutrophils, lymphocytes and macrophages, with higher neutrophils% and lymphocytes% but lower macrophages%. The Log10 (N/L) ratios were the most useful ratio to differentiate specific subclinical mastitis quarters from healthy quarters. Use of the MLD on cows with monthly composite SCC > 200 × 103 cells/ml for screening at quarter level identified quarters more likely to be culture-positive.In conclusion, the MLD can provide an analysis of mammary quarter status more detailed than provided by SCC alone; however, the MLD response to subclinical mastitis was not found useful to specifically identify the causative pathogen.

scholarly journals Molecular identification of coagulase-negative staphylococci isolated from bovine mastitis and detection of β-lactam resistance

2015 ◽  
Vol 9 (09) ◽  
pp. 1022-1027 ◽  
Author(s):  
Mariela Elizabeth Srednik ◽  
Mario Andres Grieben ◽  
Adriana Bentancor ◽  
Elida Raquel Gentilini
Keyword(s):  
Fragment Length Polymorphism ◽  
Meca Gene ◽  
Bovine Mastitis ◽  
Economic Loss ◽  
Economic Losses ◽  
Dairy Herds ◽  
Coagulase Negative Staphylococci ◽  
Milk Samples ◽  
Gap Gene ◽  
Mastitis Pathogens

Introduction: Bovine mastitis is a frequent cause of economic loss in dairy herds. Coagulase-negative staphylococci (CoNS) are increasing in importance as causeof bovine intramammary infection (IMI) throughout the world in recent years. CoNShave been isolated from milk samples collected from cows with clinical andsubclinical mastitis in several countries. Identification of mastitis pathogensis important when selection appropriate antimicrobial therapy.Methodology: A total of 93 strains of Staphylococcusspp isolated from bovine clinical andsubclinical mastitis in Argentina during 2010-2013 were identified by Restriction Fragment Length Polymorphism (RFLP)-PCR using the gap gene. The isolates were tested by PCR for the presence of blaZ gene and mecA gene and were tested by disk diffusion for the susceptibilityto penicillin and cefoxitin. Results: The most common CoNS species was S.chromogenes 46.2% (43/93), followed by S. devriesei 11.8% (11/93) and S. haemolyticus 9.7% (9/93). The blaZ gene was detected in 19 (20.4%) but only 16 (17.2%) isolates were resistant to penicillin; the mecA was detected in6 (6.5%) isolates but only 4 (4.3) were resistant to cefoxitin. The 6 mecA-positive isolates showed oxaxillinMICs ≥ 0.5 μg/ml. Discussion: CoNSare important minor mastitis pathogens and can be the cause of substantial economic losses. Despite the low resistance to PEN in Argentina, the presenceof MR isolates found in this study emphasize the importance of identificationof CoNS when an IMI is present because of the potentially risk of lateraltransfer of resistance genes between staphylococcal species.

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