scholarly journals Antimicrobial resistance profiles of Staphylococcus aureus clusters on small dairy farms in southern Brazil

2016 ◽  
Vol 36 (10) ◽  
pp. 951-956 ◽  
Author(s):  
Lilian K. Girardini ◽  
◽  
Daniel S. Paim ◽  
Thais C. Ausani ◽  
Graciela V. Lopes ◽  
...  
Keyword(s):  
Antimicrobial Resistance ◽  
Dairy Farms ◽  
Diffusion Method ◽  
Dairy Herds ◽  
Southern Brazil ◽  
Disk Diffusion Method ◽  
Banding Patterns ◽  
Lactating Cows ◽  
Resistance To Penicillin ◽  
Total Dna

ABSTRACT: In intensive dairy farming, persistent intramammary infection has been associated with specific Staphylococcus (S.) aureus strains, and these strains may be resistant to antimicrobials. The objective of this study was to evaluate the antimicrobial resistance phenotypes of S. aureus isolates and to assess the distribution and the persistence of clonal groups in small dairy herds of southern Brazil. Milk samples were collected from all lactating cows from 21 dairy farms over a two-year period, totaling 1,060 samples. S. aureus isolates were tested for susceptibility to thirteen antimicrobials using the disk diffusion method. The total DNA of the isolates was subjected to SmaI digestion followed by pulsed-field gel electrophoresis (PFGE). Banding patterns differing by ≤4 bands were considered members of a single PFGE cluster. The frequency of S. aureus isolation ranged from 3.45% to 70.59% among the 17 S. aureus-positive herds. Most S. aureus isolates (87.1%) were susceptible to all antimicrobials; resistance to penicillin (18.2%) was the most frequently observed. The 122 isolates subjected to macrorestriction analysis were classified into 30 PFGE-clusters. Among them, only 10 clusters were intermittent or persistent over the two-year period. The majority (93.6%) of isolates belonging to persistent and intermittent clusters were susceptible to all tested antimicrobials. S. aureus intramammary colonization in small dairy farms of southern Brazil is most frequently caused by sporadic PFGE clusters, although some persistent clusters can arise over time. Both sporadic and persistent isolates were highly susceptible to antimicrobials.

scholarly journals Surveillance of antimicrobial resistance of maltose negative Staphylococcus aureus in South African dairy herds

2020 ◽  
Author(s):  
Joanne Karzis ◽  
Inge-Marié Petzer ◽  
Edward F. Donkin ◽  
Vinny Naidoo ◽  
Eric M. C. Etter
Keyword(s):  
South Africa ◽  
Staphylococcus Aureus ◽  
Antimicrobial Resistance ◽  
Disk Diffusion ◽  
Diffusion Method ◽  
Dairy Herds ◽  
Disk Diffusion Method ◽  
Milk Samples ◽  
Kwazulu Natal ◽  
Over Time

Abstract Background The discovery of antimicrobials in the 1930s was one of the greatest achievements in medicine. However, bacterial resistance to antimicrobials was already observed in the 1940s and has been reported since then in both human and veterinary medicine, including in dairy cows. Many years of monitoring milk samples in South Africa, has led to the identification of a new strain of Staphylococcus aureus (S. aureus), which is maltose negative and appears to be an emerging pathogen. In this study the differences in susceptibility to antimicrobials of this strain were evaluated over time, over different seasons, in different provinces, and according to somatic cell count (SCC) categories. Results A data set of 271 maltose negative S. aureus isolates, cultured from milk samples from 117 herds out of the estimated 2000 commercial dairy herds in South Africa between 2010 and 2017, was studied using the disk diffusion method. This analysis was done using the Clinical Laboratory Standards Institute (CLSI) breakpoints in order to compare using both the previous (Intermediate category grouped with Resistant) and current definitions, (Intermediate category grouped with Susceptible). The results of the analysis between the previous and the current definitions differed for tylosin, cefalonium, oxy-tetracycline and cloxacillin. Neither the analysis using the previous nor the current systems showed an effect of province for the maltose negative S. aureus. This was in contrast to the results for maltose positive S. aureus where differences between provinces were shown in a previous study, with the lowest prevalence of resistance shown in KwaZulu-Natal during spring. For the susceptibility testing of 57 maltose negative and 57 maltose positive S. aureus isolates from 38 farms, from KwaZulu Natal, Eastern Cape and Western Cape. The minimum inhibitory concentration (MIC) results for the maltose negative S. aureus isolates confirmed the results of the disk diffusion method. Conclusions The maltose negative strains of S. aureus differed in general, in their antimicrobial resistance patterns over time, in comparison to maltose-positive S. aureus strains. MIC testing also indicated that more multidrug -resistant isolates were seen with the maltose negative S. aureus than in the maltose positive strains.

scholarly journals Surveillance of antimicrobial resistance of maltose negative Staphylococcus aureus in South African dairy herds

2020 ◽  
Author(s):  
Joanne Karzis ◽  
Inge-Marié Petzer ◽  
Edward F. Donkin ◽  
Vinny Naidoo ◽  
Eric M. C. Etter
Keyword(s):  
South Africa ◽  
Staphylococcus Aureus ◽  
Antimicrobial Resistance ◽  
Disk Diffusion ◽  
Diffusion Method ◽  
Dairy Herds ◽  
Disk Diffusion Method ◽  
Milk Samples ◽  
Kwazulu Natal ◽  
Over Time

Abstract Background The discovery of antimicrobials in the 1930s was one of the greatest achievements in medicine. However, bacterial resistance to antimicrobials was already observed in the 1940s and has been reported since then in both human and veterinary medicine, including in dairy cows. Many years of monitoring milk samples in South Africa, has led to the identification of a new strain of Staphylococcus aureus (S. aureus), which is maltose negative and appears to be an emerging pathogen. In this study the differences in susceptibility to antimicrobials of this strain were evaluated over time, over different seasons, in different provinces, and according to somatic cell count (SCC) categories. Results A data set of 271 maltose negative S. aureus isolates, cultured from milk samples from 117 herds out of the estimated 2000 commercial dairy herds in South Africa between 2010 and 2017, was studied using the disk diffusion method. This analysis was done using the Clinical Laboratory Standards Institute (CLSI) breakpoints in order to compare using both the previous (Intermediate category grouped with Resistant) and current definitions, (Intermediate category grouped with Susceptible). The results of the analysis between the previous and the current definitions differed for tylosin, cefalonium, oxy-tetracycline and cloxacillin. Neither the analysis using the previous nor the current systems showed an effect of province for the maltose negative S. aureus. This was in contrast to the results for maltose positive S. aureus where differences between provinces were shown in a previous study, with the lowest prevalence of resistance shown in KwaZulu-Natal during spring. For the susceptibility testing of 57 maltose negative and 57 maltose positive S. aureus isolates from 38 farms, from KwaZulu Natal, Eastern Cape and Western Cape. The minimum inhibitory concentration (MIC) results for the maltose negative S. aureus isolates confirmed the results of the disk diffusion method. Conclusions The maltose negative strains of S. aureus differed in general, in their antimicrobial resistance patterns over time, in comparison to maltose-positive S. aureus strains. MIC testing also indicated that more multidrug -resistant isolates were seen with the maltose negative S. aureus than in the maltose positive strains.

scholarly journals Phenotypic Antimicrobial Susceptibility of Escherichia coli from Raw Meats, Ready-to-Eat Meats, and Their Related Samples in One Health Context

2021 ◽  
Vol 9 (2) ◽  
pp. 326
Author(s):  
Frederick Adzitey ◽  
Nurul Huda ◽  
Amir Husni Mohd Shariff
Keyword(s):  
Escherichia Coli ◽  
Antimicrobial Resistance ◽  
Antimicrobial Susceptibility ◽  
Resistance Index ◽  
Diffusion Method ◽  
Resistant Bacteria ◽  
Disk Diffusion Method ◽  
E Coli ◽  
The Usa ◽  
Raw Meats

Meat is an important food source that can provide a significant amount of protein for human development. The occurrence of bacteria that are resistant to antimicrobials in meat poses a public health risk. This study evaluated the occurrence and antimicrobial resistance of E. coli (Escherichia coli) isolated from raw meats, ready-to-eat (RTE) meats and their related samples in Ghana. E. coli was isolated using the USA-FDA Bacteriological Analytical Manual and phenotypic antimicrobial susceptibility test was performed by the disk diffusion method. Of the 200 examined meats and their related samples, 38% were positive for E. coli. Notably, E. coli was highest in raw beef (80%) and lowest in RTE pork (0%). The 45 E. coli isolates were resistant ≥ 50% to amoxicillin, trimethoprim and tetracycline. They were susceptible to azithromycin (87.1%), chloramphenicol (81.3%), imipenem (74.8%), gentamicin (72.0%) and ciprofloxacin (69.5%). A relatively high intermediate resistance of 33.0% was observed for ceftriaxone. E. coli from raw meats, RTE meats, hands of meat sellers and working tools showed some differences and similarities in their phenotypic antimicrobial resistance patterns. Half (51.1%) of the E. coli isolates exhibited multidrug resistance. The E. coli isolates showed twenty-two different resistant patterns, with a multiple antibiotic resistance index of 0.0 to 0.7. The resistant pattern amoxicillin (A, n = 6 isolates) and amoxicillin-trimethoprim (A-TM, n = 6 isolates) were the most common. This study documents that raw meats, RTE meats and their related samples in Ghana are potential sources of antimicrobial-resistant E. coli and pose a risk for the transfer of resistant bacteria to the food chain, environment and humans.

scholarly journals Characterization of cefotaxime resistant Escherichia coli isolated from broiler farms in Ecuador

2018 ◽  
Author(s):  
Christian Vinueza-Burgos ◽  
David Ortega-Paredes ◽  
Cristian Narváez ◽  
Lieven De Zutter ◽  
Jeannete Zurita
Keyword(s):  
Antimicrobial Resistance ◽  
Latin American ◽  
Production Systems ◽  
Diffusion Method ◽  
Poultry Production ◽  
Disk Diffusion Method ◽  
E Coli ◽  
Resistance Patterns ◽  
Latin American Countries

AbstractAntimicrobial resistance (AR) is a worldwide concern. Up to a 160% increase in antibiotic usage in food animals is expected in Latin American countries. The poultry industry is an increasingly important segment of food production and contributor to AR. The objective of this study was to evaluate the prevalence, AR patterns and the characterization of relevant resistance genes in Extended Spectrum β-lactamases (ESBL) and AmpC E. coli from large poultry farms in Ecuador. Sampling was performed from June 2013 to July 2014 in 6 slaughterhouses that slaughter broilers from 115 farms totaling 384 flocks. Each sample of collected caeca was streaked onto TBX agar supplemented with cefotaxime (3 mg/l). In total, 176 isolates were analyzed for antimicrobial resistance patterns by the disk diffusion method and for blaCTX-M, blaTEM, blaCMY, blaSHV, blaKPC, and mcr-1 by PCR and sequencing. ESBL and AmpC E. coli were found in 362 flocks (94.3%) from 112 farms (97.4%). We found that 98.3% of the isolates were multi-resistant to antibiotics. Low resistance was observed for ertapenem and nitrofurantoin. The most prevalent ESBL genes were the blaCTX-M (90.9%) blaCTX-M-65, blaCTX-M-55 and blaCTX-M-3 alleles. Most of the AmpC strains presented the blaCMY-2 gene. Three isolates showed the mcr-1 gene. Poultry production systems represent a hotspot for antimicrobial resistance in Ecuador, possibly mediated by the extensive use of antibiotics. Monitoring this sector in national and regional plans of antimicrobial resistance surveillance should therefore be considered.

Prevalence and antimicrobial resistance of Listeria species and molecular characterization of Listeria monocytogenes isolated from retail ready-to-eat foods

2020 ◽  
Vol 367 (4) ◽  
Author(s):  
Seza Arslan ◽  
Fatma Özdemir
Keyword(s):  
Antimicrobial Resistance ◽  
Genetic Relatedness ◽  
Fragment Length Polymorphism ◽  
Food Samples ◽  
Diffusion Method ◽  
Consumer Health ◽  
Disk Diffusion Method ◽  
Listeria Species ◽  
Virulence Markers

ABSTRACT A wide variety of foods can be contaminated with Listeria species, especially L. monocytogenes. Ready-to-eat (RTE) foods are predominantly associated with human listeriosis caused by L. monocytogenes. Therefore, this study aimed to assess the presence of Listeria species in RTE foods and to characterize L. monocytogenes isolates by means of detection of virulence markers, serotypes and genetic relatedness. Of the 300 RTE food samples, 59 (19.7%) were positive for Listeria species: L. innocua (13.3%), L. monocytogenes (5%), L. welshimerii (2.3%), L. grayi subsp. murrayi (1.3%), L. grayi (1%), L. ivanovii (1%) and L. ivanovi subsp. londoniensis (0.3%). All L. monocytogenes isolates identified were positive for the actA, iap, inlA, inlB, inlC, inlJ, plcA and prfA virulence genes and biofilm. The isolates were serotyped as 1/2c (33.3%), 4b (26.7%), 1/2a (26.7%), 1/2b (6.7%) and 3c (6.7%) by the multiplex-PCR and agglutination methods. PCR-restriction fragment length polymorphism with AluI and MluCI resulted in three and two profiles, respectively. Pulsed-field gel electrophoresis differentiated the L. monocytogenes isolates into 15 ApaI and 12 AscI patterns. Antimicrobial resistance of all Listeria isolates was determined by the disk diffusion method. Most L. monocytogenes isolates were sensitive to antimicrobials used in the treatment of listeriosis. This study shows the presence of potential pathogenic and antimicrobial-resistant L. monocytogenes in RTE foods that may lead to consumer health risks.

scholarly journals Antimicrobial resistance in bacteria isolated from pigs with respiratory clinical signs in Brazil

2020 ◽  
Vol 57 (1) ◽  
pp. e160956
Author(s):  
Maysa Serpa ◽  
Juliana Amália Fonte Bôa do Nascimento ◽  
Mirian Fátima Alves ◽  
Maria Isabel Maldonado Coelho Guedes ◽  
Adrienny Trindade Reis ◽  
...  
Keyword(s):  
Antimicrobial Resistance ◽  
Antimicrobial Agents ◽  
Clinical Signs ◽  
Multidrug Resistant ◽  
Diffusion Method ◽  
Great Level ◽  
Respiratory Pathogens ◽  
Bacterial Strains ◽  
Disk Diffusion Method ◽  
Pig Farms

Antimicrobial resistance is a current and important issue to public health, and it is usually associated with the indiscriminate use of antimicrobials in animal production. This study aimed to evaluate the antimicrobial susceptibility profile in bacterial isolates from pigs with clinical respiratory signs in Brazil. One hundred sixty bacterial strains isolated from pigs from 51 pig farms in Brazil were studied. In vitro disk-diffusion method was employed using 14 antimicrobial agents: amoxicillin, penicillin, ceftiofur, ciprofloxacin, enrofloxacin, chlortetracycline, doxycycline, oxytetracycline, tetracycline, erythromycin, tilmicosin, florfenicol, lincomycin, and sulfadiazine/trimethoprim. The majority of isolates were resistant to at least one antimicrobial agent (98.75%; 158/160), while 31.25% (50/160) of the strains were multidrug resistant. Streptococcus suis and Bordetella bronchiseptica were the pathogens that showed higher resistance levels. Haemophilus parasuis showed high resistance levels to sulfadiazine/trimethoprim (9/18=50%). We observed that isolates from the midwestern and southern regions exhibited four times greater chance of being multidrug resistant than the isolates from the southeastern region studied. Overall, the results of the present study showed a great level of resistance to lincomycin, erythromycin, sulfadiazine/trimethoprim, and tetracycline among bacterial respiratory pathogens isolated from pigs in Brazil. The high levels of antimicrobial resistance in swine respiratory bacterial pathogens highlight the need for the proper use of antimicrobials in Brazilian pig farms.

scholarly journals Antimicrobial Resistance Profiles of Escherichia coli from Diarrheic Weaned Piglets after the Ban on Antibiotic Growth Promoters in Feed

Antibiotics ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 755 ◽  
Author(s):  
Do Kyung-Hyo ◽  
Byun Jae-Won ◽  
Lee Wan-Kyu
Keyword(s):  
Escherichia Coli ◽  
Antimicrobial Resistance ◽  
Diffusion Method ◽  
Growth Promoters ◽  
Disk Diffusion Method ◽  
Pathogenic Escherichia Coli ◽  
Before And After ◽  
Amoxicillin Clavulanic Acid ◽  
Antibiotic Growth Promoters ◽  
Polymerase Chain

This study aimed to survey the antimicrobial resistance profiles of 690 pathogenic Escherichia coli isolates obtained from Korean pigs with symptoms of enteric colibacillosis between 2007 and 2017, while assessing the change in antimicrobial resistance profiles before and after the ban on antibiotic growth promoters (AGPs). Following the Clinical and Laboratory Standards Institute guidelines, the antimicrobial resistance phenotype was analyzed through the disk diffusion method, and the genotype was analyzed by the polymerase chain reaction. After the ban on AGPs, resistance to gentamicin (from 68.8% to 39.0%), neomycin (from 84.9% to 57.8%), ciprofloxacin (from 49.5% to 39.6%), norfloxacin (from 46.8% to 37.3%), and amoxicillin/clavulanic acid (from 40.8% to 23.5%) decreased compared to before the ban. However, resistance to cephalothin (from 51.4% to 66.5%), cefepime (from 0.0% to 2.4%), and colistin (from 7.3% to 11.0%) had increased. We confirmed a high percentage of multidrug resistance before (95.0%) and after (96.6%) the ban on AGPs. The AmpC gene was the most prevalent from 2007 to 2017 (60.0%), followed by the blaTEM gene (55.5%). The blaTEM was prevalent before (2007–2011, 69.3%) and after (2012–2017, 49.2%) the ban on AGPs. These results provide data that can be used for the prevention and treatment of enteric colibacillosis.

scholarly journals Virulence-Associated Genes and Antimicrobial Resistance of Aeromonas hydrophila Isolates from Animal, Food, and Human Sources in Brazil

2020 ◽  
Vol 2020 ◽  
pp. 1-8
Author(s):  
Emily Moraes Roges ◽  
Verônica Dias Gonçalves ◽  
Maira Duarte Cardoso ◽  
Marcia Lima Festivo ◽  
Salvatore Siciliano ◽  
...  
Keyword(s):  
Antimicrobial Resistance ◽  
Aeromonas Hydrophila ◽  
Pathogenic Bacteria ◽  
Virulence Genes ◽  
Animal Health ◽  
Diffusion Method ◽  
Aquatic Environments ◽  
Disk Diffusion Method ◽  
Polymerase Chain ◽  
Human Source

Aeromonads are natural inhabitants of aquatic environments and may be associated with various human or animal diseases. Its pathogenicity is complex and multifactorial and is associated with many virulence factors. In this study, 110 selected Aeromonas hydrophila isolates isolated from food, animals, and human clinical material from 2010 to 2015 were analyzed. Antimicrobial susceptibility testing was performed by the disk diffusion method, and polymerase chain reaction was conducted to investigate the virulence genes hemolysin (hlyA), cytotoxic enterotoxin (act), heat-labile cytotonic enterotoxin (alt), aerolysin (aerA), and DNase-nuclease (exu). At least 92.7% of the isolates had one of the investigated virulence genes. Twenty different virulence profiles among the isolates were recognized, and the five investigated virulence genes were observed in four isolates. Human source isolates showed greater diversity than food and animal sources. Antimicrobial resistance was observed in 46.4% of the isolates, and multidrug resistance was detected in 3.6% of the isolates. Among the 120 isolates, 45% were resistant to cefoxitin; 23.5% to nalidixic acid; 16.6% to tetracycline; 13.7% to cefotaxime and imipenem; 11.8% to ceftazidime; 5.9% to amikacin, gentamicin, and sulfamethoxazole-trimethoprim; and 3.9% to ciprofloxacin and nitrofurantoin. Overall, the findings of our study indicated the presence of virulence genes and that antimicrobial resistance in A. hydrophila isolates in this study is compatible with potentially pathogenic bacteria. This information will allow us to recognize the potential risk through circulating isolates in animal health and public health and the spread through the food chain offering subsidies for appropriate sanitary actions.

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.

Staphylococci among Wild European Rabbits from the Azores: A Potential Zoonotic Issue?

2020 ◽  
Vol 83 (7) ◽  
pp. 1110-1114 ◽  
Author(s):  
MARGARIDA SOUSA ◽  
VANESSA SILVA ◽  
ADRIANA SILVA ◽  
NUNO SILVA ◽  
JESSICA RIBEIRO ◽  
...  
Keyword(s):  
Antimicrobial Resistance ◽  
Resistance Genes ◽  
Meca Gene ◽  
Diffusion Method ◽  
Coagulase Negative Staphylococci ◽  
Spa Typing ◽  
Disk Diffusion Method ◽  
Genetic Lineages ◽  
Antimicrobial Resistance Genes ◽  
European Rabbits

ABSTRACT The prevalence and diversity of Staphylococcus species from wild European rabbits (Oryctolagus cuniculus) in the Azores were investigated, and the antibiotic resistance phenotype and genotype of the isolates were determined. Nasal samples from 77 wild European rabbits from São Jorge and São Miguel islands in Azores were examined. Antibiotic susceptibility of the isolates was determined using the Kirby-Bauer disk diffusion method, and the presence of antimicrobial resistance genes and virulence factors was determined by PCR. The genetic lineages of S. aureus isolates were characterized by spa typing and multilocus sequence typing. A total of 49 staphylococci were obtained from 35 of the 77 wild rabbits. Both coagulase-positive (8.2%) and coagulase-negative (91.8%) staphylococci were detected: 4 S. aureus, 17 S. fleurettii, 13 S. sciuri, 7 S. xylosus, 4 S. epidermidis, and 1 each of S. simulans, S. saprophyticus, S. succinus, and S. equorum. The four S. aureus isolates showed methicillin susceptibility and were characterized as spa type t272/CC121, Panton-Valentine leukocidin negative, and hlB positive. Most of the coagulase-negative staphylococci showed resistance to fusidic acid and beta-lactams, and multidrug resistance was identified especially among S. epidermidis isolates. The mecA gene was detected in 20 isolates of the species S. fleurettii and S. epidermidis, associated with the blaZ gene in one S. epidermidis isolate. Five antimicrobial resistance genes were detected in one S. epidermidis isolate (mecA,dfrA,dfrG,aac6′-aph2′′, and ant4). Our results highlight that wild rabbits are reservoirs or “temporary hosts” of Staphylococcus species with zoonotic potential, some of them carrying relevant antimicrobial resistances. HIGHLIGHTS

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