scholarly journals Antimicrobial Resistance of Major Bacterial Pathogens from Dairy Cows with High Somatic Cell Count and Clinical Mastitis

Animals ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 131
Author(s):  
Reta D. Abdi ◽  
Barbara E. Gillespie ◽  
Susan Ivey ◽  
Gina M. Pighetti ◽  
Raul A. Almeida ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Antimicrobial Resistance ◽  
Cell Count ◽  
Somatic Cell Count ◽  
Dairy Farms ◽  
Clinical Mastitis ◽  
Bacterial Isolates ◽  
E Coli ◽  
Etiological Agents ◽  
Klebsiella Spp

Mastitis is the most prevalent and economically important disease caused by different etiological agents, which leads to increased somatic cell count (SCC) and low milk quality. Treating mastitis cases with antimicrobials is essential to reduce SCC and improve milk quality. Non-prudent use of antimicrobials in dairy farms increased the development of antimicrobial resistant bacteria. This study’s objectives were (1) to isolate and identify etiological agents of mastitis and (2) to determine antimicrobial resistance profiles of bacterial isolates. A total of 174 quarter milk samples from 151 cows with high SCC and clinical mastitis from 34 dairy farms in Tennessee, Kentucky, and Mississippi were collected. Bacterial causative agents were determined by bacteriological and biochemical tests. The antimicrobial resistance of bacterial isolates against 10 commonly used antimicrobials was tested. A total of 193 bacteria consisting of six bacterial species, which include Staphylococcus aureus, Streptococcus uberis, Streptococcus dysgalactiae, Escherichia coli, Klebsiella oxytoca and Klebsiella pneumoniae were isolated. Staphylococcus aureus was the predominant isolate followed by Strep. spp., E. coli, and Klebsiella spp. Results of this study showed that Gram-negatives (E. coli and Klebsiella spp.) were more resistant than Gram-positives (Staph. aureus and Streptococcus spp.). Continuous antimicrobial resistance testing and identification of reservoirs of resistance traits in dairy farms are essential to implement proper mitigation measures.

scholarly journals Characterization of Staphylococcus aureus Isolates From Cases of Clinical Bovine Mastitis on Large-Scale Chinese Dairy Farms

2020 ◽  
Vol 7 ◽  
Author(s):  
Kangjun Liu ◽  
Luyao Tao ◽  
Jianji Li ◽  
Li Fang ◽  
Luying Cui ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Cluster Analysis ◽  
Antimicrobial Resistance ◽  
Large Scale ◽  
Bovine Mastitis ◽  
Dairy Farms ◽  
Clinical Mastitis ◽  
Maldi Tof Ms ◽  
Maldi Tof ◽  
Tof Ms

Bovine mastitis is a prevalent disease that causes serious economic problems globally in the dairy industry. Staphylococcus aureus is an important pathogen of bovine mastitis. This study was conducted to characterize S. aureus isolates from clinical bovine mastitis cases in large-scale dairy herds in China. S. aureus was isolated from 624 clinical mastitis cases and confirmed by matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS). In total, 62 S. aureus isolates were obtained. Cluster analysis, genetic diversity, quantification of biofilm formation, antimicrobial resistance, and detection of virulence genes were performed on these isolates of S. aureus. Eight isolates harbored the mecA gene and were sensitive to oxacillin. MALDI-TOF MS cluster analysis revealed that the 62 isolates were divided into three major clusters (I, II, III) and eight main groups (A–H) at the distance level of 700. The agr II was the most prevalent (56.5%). The 62 S. aureus isolates were assigned to seven spa types. The most common spa type was t529(58.1%), followed by t2196 (14.5%), t518 (14.5%), t571(6.5%), t034 (3.2%), t2734 (1.6%), and t730 (1.6%). Five STs were identified from seven representative isolates as follows: ST630/CC8, ST97/CC97, ST50, ST398, and ST705. All isolates had the ability to form biofilm. Antimicrobial resistance was most frequently observed to ciprofloxacin (29%), followed by penicillin (24.2%), and streptomycin (9.6%). All isolates harbored the fnbA, clfB (100%), icaA, and icaD genes. This study provides the basis for the development of bovine mastitis prevention program on large-scale dairy farms.

scholarly journals Farm records in investigation of epidemiology, symptomatology and causes of clinical mastitis in a dairy farm

2019 ◽  
Vol 35 (1) ◽  
pp. 97-110
Author(s):  
Dino Haracic ◽  
Sabina Seric-Haracic ◽  
Ermin Saljic ◽  
Nihad Fejzic
Keyword(s):  
Antimicrobial Resistance ◽  
Somatic Cell ◽  
Cell Count ◽  
Somatic Cell Count ◽  
Dairy Farm ◽  
Clinical Mastitis ◽  
Infectious Agents ◽  
Coagulase Negative Staphylococci ◽  
Causative Agents ◽  
On Farm

Mastitis is one of the most important diseases in dairy cow farms and one of the most common cause for antibiotic treatment. Aims of this study were: to investigate frequency and trends of clinical mastitis in cows on a large dairy farm, describe clinical characteristics of mastitis and investigate causative infectious agents in selected cases alongside antimicrobial resistance. In our study we used farm records for clinical mastitis recorded for period 2016 and 2017. We also used results of the regular on farm testing of the somatic cell count for 2017. Samples of milk from all clinical mastitis cases were taken during November and December 2017 in order to investigate causative agents and their antimicrobial resistance. Occurrence of clinical mastitis was 205 cases (47.7%) in 2017 compared to 93 cases (29.7%) recorded in 2016. In 2017 reoccurrence of clinical mastitis in same animal was recorded for 93 cows (45.4%). In 2016 reoccurrence of clinical mastitis in same animal was recoded for 49 cows (29.7%). Average course of clinical mastitis in 2016 was 3 days, while in 2017 4.5 days (continuous days of recording a case in farm records). Somatic cell count in more than half of tested animals was higher than 200.000 SC/ml according to the measurements from February and July 2017 (number of cows tested 236 and 169, respectively). Out of 23 milk samples, 20 had bacteriological growth. In 9 samples we identified S.aureus, in 6 streptococcus spp., in 4 coagulase negative staphylococci (CNS) and one sample contained E.coli. Most common resistance was found for lincomycin-spectinomycin (100%) gentamicin (92%), followed by cefquinome (65%), linkomycin (53%) and erythromycin (47%). Isolates of S.aureus were resistant on the largest number of investigated antibiotics.

scholarly journals Microbial Aetiology, Antibiotic Susceptibility and Pathogen-Specific Risk Factors for Udder Pathogens from Clinical Mastitis in Dairy Cows

Animals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 2113
Author(s):  
Anna Duse ◽  
Karin Persson-Waller ◽  
Karl Pedersen
Keyword(s):  
Risk Factors ◽  
Staphylococcus Aureus ◽  
Antibiotic Resistance ◽  
Dairy Cows ◽  
Antibiotic Susceptibility ◽  
Clinical Mastitis ◽  
Gram Positive ◽  
E Coli ◽  
Trueperella Pyogenes ◽  
Klebsiella Spp

Mastitis is one of the most important infectious diseases and one of the diseases that causes the greatest use of antibiotics in dairy cows. Therefore, updated information on the bacteria that cause mastitis and their antibiotic susceptibility properties is important. Here, for the first time in over 10 years, we updated the bacterial findings in clinical mastitis in Swedish dairy cows together with their antibiotic resistance patterns and risk factors for each bacterial species. During the period 2013–2018, samples from clinical mastitis were collected, together with information on the cows and herds of origin. The samples were cultured, and a total of 664 recovered bacterial isolates were subjected to susceptibility testing. Staphylococcus aureus (S. aureus) was the most common pathogen and accounted for 27.8% of diagnoses, followed by Streptococcus dysgalactiae (S. dysgalactiae) (15.8%), Escherichia coli (E. coli) (15.1%), Streptococcus uberis (S. uberis) (11.4%), Trueperella pyogenes (T. pyogenes) (7.7%), non-aureus staphylococci (NAS) (2.8%), Klebsiella spp. (2.7%), Enterococcus spp. (1.3%), and Streptococcus agalactiae (S. agalactiae) (1.2%). Various other bacteria accounted for 2.6%. Staphylococci were, in general, susceptible to most antibiotics, but 2.6% of S. aureus and 30.4% of NAS were resistant to penicillin. No methicillin-resistant staphylococci were found. All S. agalactiae were susceptible to penicillin. Bimodal and trimodal MIC distributions for penicillin in S. dysgalactiae and S. uberis, respectively, indicate acquired reduced susceptibility in some isolates. The mostly unimodal MIC distributions of T. pyogenes indicate that acquired resistance does usually not occur in this species. Among E. coli, 14.7% were resistant to at least one antibiotic, most often ampicillin (8.7%), streptomycin (7.8%), or sulphamethoxazole (6.9%). Klebsiella spp. had low resistance to tetracycline (9.1%) but is considered intrinsically resistant to ampicillin. Pathogen-specific risk factors were investigated using multivariable models. Staphylococcus aureus, S. dysgalactiae, and T. pyogenes were more common, while E. coli was less common in quarters with more than one pathogen. S. aureus and T. pyogenes were mostly seen in early lactation, while E. coli was more common in peak to mid lactation and S. dysgalactiae in early to peak lactation. Trueperella pyogenes and Klebsiella spp. were associated with a previous case of clinical mastitis in the current lactation. Staphylococcus aureus was associated with tie stalls and T. pyogenes with loose housing. All pathogens except E. coli and S. dysgalactiae had a seasonal distribution. In conclusion, the aetiological agents for clinical bovine mastitis have remained relatively stable over the last 10–15 years, S. aureus, S. dysgalactiae, E. coli and S. uberis being the most important. Resistance to penicillin among Gram-positive agents was low, and in general, antibiotic resistance to other compounds was low among both Gram-positive and Gram-negative agents.

scholarly journals Surveillance of antimicrobial resistance of invasive pathogens: the Estonian experience

2006 ◽  
Vol 11 (2) ◽  
pp. 9-10 ◽  
Author(s):  
K Loivukene ◽  
K Kermes ◽  
E Sepp ◽  
V Adamson ◽  
P Mitt ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Antimicrobial Resistance ◽  
Surveillance System ◽  
Gram Negative ◽  
E Coli ◽  
Invasive Pathogens ◽  
Susceptibility Data ◽  
Antimicrobial Resistance Surveillance ◽  
Klebsiella Spp

The aim of the present study was to evaluate the needs for surveillance of invasive Gram-negative pathogens in Estonia. The antimicrobial susceptibility data of invasive isolates of Acinetobacter baumannii, Pseudomonas aeruginosa, Klebsiella spp, Escherichia coli, Staphylococcus aureus, Streptococcus pneumoniae and enterococci were collected in accordance with EARSS (European Antimicrobial Resistance Surveillance System) protocols. Despite the higher rate of Gram positive pathogens, their resistance to antimicrobials was low in contrast to the elevated resistance established for Gram negative pathogens. The higher resistance to antimicrobials was particularly associated with A. baumannii and P. aeruginosa. Also, the proportion of extended spectrum betalactamase (ESBL)-producing strains was 23% among Klebsiella spp. and 3.6% among E. coli. The inclusion of invasive Gram negative pathogens in antimicrobial resistance surveillance provides useful information concerning local pathogen susceptibility, as well as for the empirical treatment of suspected infections.

scholarly journals Virulence determinants and antimicrobial resistance of E. coli isolated from bovine clinical mastitis in some selected dairy farms of Bangladesh

2021 ◽  
Author(s):  
Md. Abdus Sattar Bag ◽  
Md. Shahidur Rahman Khan ◽  
Md. Deluar Hossain Sami ◽  
Ferdousi Begum ◽  
Md. Shafiqul Islam ◽  
...  
Keyword(s):  
Antimicrobial Resistance ◽  
Dairy Farms ◽  
Clinical Mastitis ◽  
Virulence Determinants ◽  
E Coli

Association between Somatic Cell Count, Electric Conductivity and pH in Diagnosis of Subclinical Mastitis in Crossbred Cows

2018 ◽  
Vol 13 (03) ◽  
Author(s):  
Shekhar Sahu ◽  
S. Nanavati ◽  
S. S. Tomar ◽  
D. S. Yadav ◽  
M. S. Jamra ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Somatic Cell ◽  
Cell Count ◽  
Somatic Cell Count ◽  
Significant Positive Correlation ◽  
Dairy Farms ◽  
Subclinical Mastitis ◽  
Clinical Mastitis ◽  
Crossbred Cows

The objective of the present study was to determine the relation between somatic cell count (SCC), Electrical conductivity (EC) and pH of milk for diagnosis of subclinical (SCM) and clinical mastitis (CM). For this a total of 120 samples were collected from crossbred cows of organised and norganised dairy farms for determination of EC, SCC and pH. On the basis of SCC, the cows were categorized as healthy(SCC below 2×105 per ml), subclinical mastitis (SCC in the range 2×105 - 3×105 per ml)and mastitis(SCC more than 3×105 per ml).The values of milk SCC and EC were significantly (P less than 0.05) higher in crossbred cows having subclinical and clinical mastitis. Milk pH ranged from 6.48 to 6.62 in healthy and subclinical cases,whereas pH 7.03 was observed in clinical mastitis cases. There was a significant positive correlation (P less than 0.05) between SCC, EC and milk pH.

Association between isolation of Staphylococcus aureus one week after calving and milk yield, somatic cell count, clinical mastitis, and culling through the remaining lactation

2008 ◽  
Vol 76 (1) ◽  
pp. 24-35 ◽  
Author(s):  
Anne Cathrine Whist ◽  
Olav Østerås ◽  
Liv Sølverød
Keyword(s):  
Staphylococcus Aureus ◽  
Somatic Cell ◽  
Cell Count ◽  
Milk Yield ◽  
Somatic Cell Count ◽  
Yield Curve ◽  
Clinical Mastitis ◽  
Hazard Ratio ◽  
Staph Aureus ◽  
Culture Negative

Cows with isolation of Staphylococcus aureus approximately 1 week after calving and milk yield, somatic cell count (SCC), clinical mastitis (CM), and culling risk through the remaining lactation were assessed in 178 Norwegian dairy herds. Mixed models with repeated measures were used to compare milk yield and SCC, and survival analyses were used to estimate the hazard ratio for CM and culling. On average, cows with an isolate of Staph. aureus had a significantly higher SCC than culture-negative cows. If no post-milking teat disinfection (PMTD) was used, the mean values of SCC were 42 000, 61 000, 68 000 and 77 000 cells/ml for cows with no Staph. aureus isolate, with Staph. aureus isolated in 1 quarter, in 2 quarters and more than 2 quarters respectively. If iodine PMTD was used, SCC means were 36 000; 63 000; 70 000 and 122 000, respectively. Primiparous cows testing positive for Staph. aureus had the same milk yield curve as culture-negative cows, except for those with Staph. aureus isolated in more than 2 quarters. They produced 229 kg less during a 305-d lactation. Multiparous cows with isolation of Staph. aureus in at least 1 quarter produced 94–161 kg less milk in 2nd and >3rd parity, respectively, and those with isolation in more than 2 quarters produced 303–390 kg less than multiparous culture-negative animals during a 305-d lactation. Compared with culture-negative cows, the hazard ratio for CM and culling in cows with isolation of Staph. aureus in at least 1 quarter was 2·0 (1·6–2·4) and 1·7 (1·5–1·9), respectively. There was a decrease in the SCC and in the CM risk in culture-negative cows where iodine PMTD had been used, indicating that iodine PMTD has a preventive effect on already healthy cows. For cows testing positive for Staph. aureus in more than 2 quarters at calving, iodine PMTD had a negative effect on the CM risk and on the SCC through the remaining lactation.

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