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125400.9586Genetic diversity and antimicrobial resistance of Staphylococcus aureus from recurrent tonsillitis in children. The aim of this study was to analyze the prevalence of Staphylococcus aureus in the tonsils of children subjected tonsillectomy due to recurrent tonsilitis and to determine the spa types of the pathogens, carriage of virulence genes and antimicrobial resistance profiles. The study included 73 tonsillectomized children. Bacteria, including S. aureus were isolated from tonsillar surface prior to tonsillectomy, recovered from tonsillar core at the time of the surgery, and from posterior pharynx 2-4 weeks after the procedure. Staphylococcus aureus isolates were compared by spa typing, tested for antimicrobial susceptibility and for the presence of superantigenic toxin genes (sea-seu, eta, etb, tst, lukS/lukF-PV) by multiplex polymerase chain reaction. Seventy-three patients (mean 7.1 ± 4.1 years, 61.6% male) were assessed. The most commonly isolated bacteria were S. aureus. The largest proportion of staphylococcal isolates originated from tonsillar core (63%), followed by tonsillar surface (45.1%) and posterior pharynx in tonsillectomized children (18.2%, p = 0.007). Five (6.3%) isolates were identified as MRSA (mecA-positive). Up to 67.5% of the isolates synthesized penicillinases (blaZ-positive isolates), and 8.8% displayed MLS(B) resistance. The superantigenic toxin genes were detected in more than half of examined isolates (56.3%). spa types t091, t084, and t002, and clonal complexes (CCs) CC7, CC45, and CC30 turned out to be most common. Staphylococcus aureus associated with RT in children showed pathogenicity potential and considerable genetic diversity, and no clones were found to be specific for this condition although further studies are needed.202031692060
125710.9584Antimicrobial Susceptibility Pattern in the Bacteria Isolated from Surgical Site Infection: Emphasis on Staphylococcus Aureus; Yasuj City, Southwest Iran. BACKGROUND: Surgical site infections (SSIs) in surgical wards remains the most common cause of postoperative complications and realistically is the third most common origin of healthcare-related conditions. Staphylococcus aureus is undoubtedly the most common bacteria causing SSIs. The current study aimed at investigating the antimicrobial susceptibility pattern in bacteria isolated from SSIs, evaluation of tetracycline resistance genes, and SCCmec typing in S. aureus isolates isolated from patients with SSIs from 2018 to 2019 in Yasuj, Kohgiluyeh, and Boyer-Ahmad Province, Iran. METHODS: This study diligently investigated 240 potential patients. Antimicrobial susceptibility testing was performed properly by the disk diffusion method. For the final confirmation of isolated bacteria, PCR was used. The presence of tet genes and SCCmec typing was carried out by multiplex PCR. RESULTS: The results showed that the most common isolated pathogens included S. aureus, E. coli, P. aeruginosa, Coagulase-negative Staphylococci, and K. pneumonia in 58.8%, 19.8%, 9.2%, 6.8% and 5.4% of cases, respectively. The majority of the Gram positive isolates were resistant against penicillin (86%) and Gram negative were resistant against ciprofloxacin (75.6%). In isolates of Staphylococcus aureus, the mecA gene was detected in 63.6% of isolates. The predominant SCCmec types were type III (59.1%) and type I (18.4%). The tetK and tetM genes were detected in 80.7% and 71.9% of the S. aureus isolates, respectively. There was a statistically significant difference between tet genes (tetK and tetM) from the viewpoint of resistance to tetracycline (p = 0.024). CONCLUSIONS: According to the results of the current study, it is recommended to administer vancomycin, amikacin, and imipenem in Yasuj to treat SSIs.202133616327
125520.9580Emergence of quinupristin/dalfopristin resistance among livestock-associated Staphylococcus aureus ST9 clinical isolates. Quinupristin/dalfopristin (Q/D) is a valuable alternative to vancomycin for the treatment of meticillin-resistant Staphylococcus aureus (MRSA) infections. However, not long after Q/D was approved, bacteria with resistance to this newer antimicrobial agent were reported. To investigate the prevalence of Q/D resistance, a total of 1476 non-duplicate S. aureus isolates, including 775 MRSA, from a Chinese tertiary hospital were selected randomly from 2003 to 2013. Of the 775 MRSA, 3 (0.4%) were resistant to Q/D. All meticillin-susceptible S. aureus were susceptible to Q/D. The prevalence of Q/D resistance among S. aureus was 0.2% (3/1476). The three isolates with Q/D resistance had the same antimicrobial resistance profile, except for cefaclor and chloramphenicol. All three Q/D-resistant MRSA were positive for five streptogramin B resistance genes (ermA, ermB, ermC, msrA and msrB) and two streptogramin A resistance genes (vatC and vgaA) as determined by PCR and DNA sequencing. MRSA WZ1031 belonged to ST9-MRSA-SCCmecV-t899, whilst MRSA WZ414 and WZ480 belonged to ST9-MRSA-SCCmecNT(non-typeable)-t899. ST9 has been reported predominantly in livestock-associated (LA) MRSA in some Asian countries. The three patients with these MRSA isolates were not livestock handlers and did not keep close contact with livestock. The origin of these important LA-MRSA isolates causing human infections is not known. Taken together, Q/D resistance, which was caused by a combination of ermA-ermB-ermC-msrA-msrB-vatC-vgaA, was first found among S. aureus clinical isolates in China. The present study is the first report of the emergence of human infections caused by ST9 LA-MRSA isolates with Q/D resistance.201425218154
128330.9577Antimicrobial Resistance Profiles of Staphylococcus Isolated from Cows with Subclinical Mastitis: Do Strains from the Environment and from Humans Contribute to the Dissemination of Resistance among Bacteria on Dairy Farms in Colombia? Staphylococcus is a very prevalent etiologic agent of bovine mastitis, and antibiotic resistance contributes to the successful colonization and dissemination of these bacteria in different environments and hosts on dairy farms. This study aimed to identify the antimicrobial resistance (AMR) genotypes and phenotypes of Staphylococcus spp. isolates from different sources on dairy farms and their relationship with the use of antibiotics. An antimicrobial susceptibility test was performed on 349 Staphylococcus strains (S. aureus, n = 152; non-aureus staphylococci (NAS), n = 197) isolated from quarter milk samples (QMSs) from cows with subclinical mastitis (176), the teats of cows (116), the milking parlor environment (32), and the nasal cavities of milk workers (25). Resistance and multidrug resistance percentages found for S. aureus and NAS were (S. aureus = 63.2%, NAS = 55.8%) and (S. aureus = 4.6%, NAS = 11.7%), respectively. S. aureus and NAS isolates showed resistance mainly to penicillin (10 IU) (54.1% and 32.4%) and ampicillin (10 mg) (50.3% and 27.0%) drugs. The prevalence of AMR Staphylococcus was higher in environmental samples (81.3%) compared to other sources (52.6-76.0%). In S. aureus isolates, the identification of the blaZ (83.9%), aacAaphD (48.6%), ermC (23.5%), tetK (12.9%), and mecA (12.1%) genes did not entirely agree with the AMR phenotype. We conclude that the use of β-lactam antibiotics influences the expression of AMR in Staphylococcus circulating on dairy farms and that S. aureus isolates from the environment and humans may be reservoirs of AMR for other bacteria on dairy farms.202337998777
125840.9574Occurrence of antimicrobial resistance and antimicrobial resistance genes in methicillin-resistant Staphylococcus aureus isolated from healthy rabbits. BACKGROUND AND AIM: Methicillin-resistant globally, Staphylococcus aureus (MRSA) is a major cause of disease in both humans and animals. Several studies have documented the presence of MRSA in healthy and infected animals. However, there is less information on MRSA occurrence in exotic pets, especially healthy rabbits. This study aimed to look into the antimicrobial resistance profile, hidden antimicrobial-resistant genes in isolated bacteria, and to estimate prevalence of MRSA in healthy rabbits. MATERIALS AND METHODS: Two-hundreds and eighteen samples, including 42 eyes, 44 ears, 44 oral, 44 ventral thoracic, and 44 perineal swabs, were taken from 44 healthy rabbits that visited the Prasu-Arthorn Animal Hospital, in Nakornpathom, Thailand, from January 2015 to March 2016. The traditional methods of Gram stain, mannitol fermentation, hemolysis on blood agar, catalase test, and coagulase production were used to confirm the presence of Staphylococcus aureus in all specimens. All bacterial isolates were determined by antimicrobial susceptibility test by the disk diffusion method. The polymerase chain reaction was used to identify the antimicrobial-resistant genes (blaZ, mecA, aacA-aphD, msrA, tetK, gyrA, grlA, and dfrG) in isolates of MRSA with a cefoxitin-resistant phenotype. RESULTS: From 218 specimens, 185 S. aureus were isolated, with the majority of these being found in the oral cavity (29.73%) and ventral thoracic area (22.7%), respectively. Forty-seven (25.41%) MRSAs were found in S. aureus isolates, with the majority of these being found in the perineum (16, 34.04%) and ventral thoracic area (13, 27.66%) specimens. Among MRSAs, 29 (61.7%) isolates were multidrug-resistant (MDR) strains. Most of MRSA isolates were resistant to penicillin (100%), followed by ceftriaxone (44.68%) and azithromycin (44.68%). In addition, these bacteria contained the most drug-resistance genes, blaZ (47.83%), followed by gyrA (36.17%) and tetK (23.4%). CONCLUSION: This study revealed that MRSA could be found even in healthy rabbits. Some MRSAs strains were MDR-MRSA, which means that when an infection occurs, the available antibiotics were not effective in treating it. To prevent the spread of MDR-MRSA from pets to owners, it may be helpful to educate owners about effective prevention and hygiene measures.202236590129
128250.9573Subclinical Mastitis in Selected Bovine Dairy Herds in North Upper Egypt: Assessment of Prevalence, Causative Bacterial Pathogens, Antimicrobial Resistance and Virulence-Associated Genes. Mastitis is a significant disease affecting dairy cattle farms in Egypt. The current study aimed to investigate the prevalence and major bacterial pathogens causing subclinical mastitis (SCM) in three bovine dairy herds, with a history of SCM, at three Governorates in North Upper Egypt. The antimicrobial resistance profiles and specific virulence-associated genes causing bovine SCM were investigated. One thousand sixty-quarter milk samples (QMS) were collected aseptically from 270 apparently healthy cows in three farms and examined. The total prevalence of SCM was 46% and 44.8% based on California Mastitis Test (CMT) and Somatic Cell Count (SCC), respectively. Bacteriological examination of CMT positive quarters revealed that the prevalence of bacterial isolation in subclinically mastitic quarters was 90.4% (26 and 64.3% had single and mixed isolates, respectively). The most frequent bacterial isolates were E. coli (49.8%), Staphylococcus aureus (44.9%), streptococci (44.1%) and non-aureus staphylococci (NAS) (37.1%). Antimicrobial susceptibility testing of isolates revealed a high degree of resistance to the most commonly used antimicrobial compound in human and veterinary medicine. Implementation of PCR revealed the presence of mecA and blaZ genes in 60% and 46.7% of S. aureus isolates and in 26.7% and 53.3% of NAS, respectively. Meanwhile 73.3% of streptococci isolates harbored aph(3')-IIIa gene conferring resistance to aminoglycosides and cfb gene. All E. coli isolates harbored tetA gene conferring resistance to tetracycline and sul1 gene conferring resistance to sulfonamides. The fimH and tsh genes were found in 80% and 60%, respectively. A significant association between the phenotypes and genotypes of AMR in different bacteria was recorded. The presence of a high prevalence of SCM in dairy animals impacts milk production and milk quality. The coexistence of pathogenic bacteria in milk is alarming, threatens human health and has a public health significance. Herd health improvement interventions are required to protect human health and society.202134072543
122360.9572Characterization of Escherichia coli virulence genes, pathotypes and antibiotic resistance properties in diarrheic calves in Iran. BACKGROUND: Calf diarrhea is a major economic concern in bovine industry all around the world. This study was carried out in order to investigate distribution of virulence genes, pathotypes, serogroups and antibiotic resistance properties of Escherichia coli isolated from diarrheic calves. RESULTS: Totally, 76.45% of 824 diarrheic fecal samples collected from Isfahan, Chaharmahal, Fars and Khuzestan provinces, Iran were positive for E. coli and all of them were also positive for cnf2, hlyA, cdtIII, f17c, lt, st, stx1, eae, ehly, stx2 and cnf1 virulence genes. Chaharmahal had the highest prevalence of STEC (84.61%), while Isfahan had the lowest (71.95%). E. coli serogroups had the highest frequency in 1-7 days old calves and winter season. Distribution of ETEC, EHEC, AEEC and NTEC pathotypes among E. coli isolates were 28.41%, 5.07%, 29.52% and 3.49%, respectively. Statistical analyses were significant for presence of bacteria between various seasons and ages. All isolates had the high resistance to penicillin (100%), streptomycin (98.25%) and tetracycline (98.09%) antibiotics. The most commonly detected resistance genes were aadA1, sul1, aac[3]-IV, CITM, and dfrA1. The most prevalent serogroup among STEC was O26. CONCLUSIONS: Our findings should raise awareness about antibiotic resistance in diarrheic calves in Iran. Clinicians should exercise caution when prescribing antibiotics.201425052999
138170.9570Differences in antimicrobial resistance-related genes of Trueperella pyogenes between isolates detected from cattle and pigs. We investigated antimicrobial resistance-related genes in 109 isolates of Trueperella pyogenes that were isolated in cattle and pigs. All 89 tetracycline-resistant T. pyogenes isolates carried the resistance gene harbored either tetW, tetM, tetA(33), tetK, or tetL. The ermX or ermB were detected in 18 of 23 erythromycin-resistant isolates. Streptomycin-resistant aadA1, aadA9, aadA11, aadA24, strA, or strB were detected in 25 of 83 isolates. There were significant differences in the percentages of tetA(33), ermB, aadA1, aadA9, aadA11, or aadA24 carriage between cattle and pig isolates. In addition, the Class 1 gene cassette was detected only in 17 cattle isolates. This suggests that T. pyogenes isolates acquire resistance gene in each environment of cattle and pigs, and that the transmission of the bacteria between cattle and pigs is limited.202439293943
126780.9568Detection and characterization of methicillin-resistant and susceptible coagulase-negative staphylococci in milk from cows with clinical mastitis in Tunisia. OBJECTIVES: This study investigated prevalence of methicillin-resistant (MR) and methicillin-susceptible (MS) coagulase-negative staphylococci (CNS) and the implicated mechanisms of resistance and virulence in milk of mastitis cows. In addition, the presence of SCCmec type was analyzed in MR Staphylococcus epidermidis (MRSE). RESULTS: Three hundred milk samples from cows with clinical mastitis were obtained from 30 dairy farms in different regions of Tunisia. Sixty-eight of the 300 tested samples contained CNS strains. Various CNS species were identified, with Staphylococcus xylosus being the most frequently found (40%) followed by Staphylococcus warneri (12%). The mecA gene was present in 14 of 20 MR-CNS isolates. All of them were lacking the mecC gene. The SCCmecIVa was identified in four MRSE isolates. Most of CNS isolates showed penicillin resistance (70.6%) and 58.3% of them carried the blaZ gene. MR-CNS isolates (n = 20) showed resistance to erythromycin, tetracycline and trimethoprim-sulfametoxazole harboring different resistance genes such us erm(B), erm(T), erm(C), mph(C) or msr(A), tet(K) and dfr(A). However, a lower percentage of resistance was observed among 48 MS-CNS isolates: erythromycin (8.3%), tetracycline (6.2%), streptomycin (6.2%), clindamycin (6.2%), and trimethoprim-sulfametoxazole (2%). The Inu(B) gene was detected in one Staphylococcus xylosus strain that showed clindamycin resistance. The virulence gene tsst-1 was observed in one MR-CNS strain. DISCUSSION: Coagulase-negative staphylococci containing a diversity of antimicrobial resistance genes are frequently detected in milk of mastitis cows. This fact emphasizes the importance of identifying CNS when an intramammary infection is present because of the potential risk of lateral transfer of resistant genes among staphylococcal species and other pathogenic bacteria.201830077662
130290.9566A survey of prevalence and phenotypic and genotypic assessment of antibiotic resistance in Staphylococcus aureus bacteria isolated from ready-to-eat food samples collected from Tehran Province, Iran. BACKGROUND: Resistant Staphylococcus aureus (S. aureus) bacteria are considered among the major causes of foodborne diseases. This survey aims to assess genotypic and phenotypic profiles of antibiotic resistance in S. aureus bacteria isolated from ready-to-eat food samples. METHODS: According to the previously reported prevalence of S. aureus in ready-to-eat food samples, a total of 415 ready-to-eat food samples were collected from Tehran province, Iran. S. aureus bacteria were identified using culture and biochemical tests. Besides, the phenotypic antibiotic resistance profile was determined by disk diffusion. In addition, the genotypic pattern of antibiotic resistance was determined using the PCR. RESULTS: A total of 64 out of 415 (15.42%) ready-to-eat food samples were contaminated with S. aureus. Grilled mushrooms and salad olivieh harbored the highest contamination rate of (30%), while salami samples harbored the lowest contamination rate of 3.33%. In addition, S. aureus bacteria harbored the highest prevalence of resistance to penicillin (85.93%), tetracycline (85.93%), gentamicin (73.43%), erythromycin (53.12%), trimethoprim-sulfamethoxazole (51.56%), and ciprofloxacin (50%). However, all isolates were resistant to at least four antibiotic agents. Accordingly, the prevalence of tetK (70.31%), blaZ (64.06%), aacA-D (57.81%), gyrA (50%), and ermA (39.06%) was higher than that of other detected antibiotic resistance genes. Besides, AacA-D + blaZ (48.43%), tetK + blaZ (46.87%), aacA-D + tetK (39.06%), aacA-D + gyrA (20.31%), and ermA + blaZ (20.31%) were the most frequently identified combined genotypic patterns of antibiotic resistance. CONCLUSION: Ready-to-eat food samples may be sources of resistant S. aureus, which pose a hygienic threat in case of their consumption. However, further investigations are required to identify additional epidemiological features of S. aureus in ready-to-eat foods.202134635183
1301100.9565Phenotypic and Genotypic Assessment of Antibiotic Resistance of Staphylococcus aureus Bacteria Isolated from Retail Meat. BACKGROUND: Resistant Staphylococcus aureus (S. aureus) bacteria are determined to be one of the main causes of foodborne diseases. PURPOSE: This survey was done to assess the genotypic and phenotypic profiles of antibiotic resistance of S. aureus bacteria isolated from retail meat. METHODS: Four-hundred and eighty-five retail meat samples were collected and examined. S. aureus bacteria were identified using culture and biochemical tests. The phenotypic profile of antibiotic resistance was examined using the disk diffusion method. The genotypic pattern of antibiotic resistance was determined using the polymerase chain reaction. RESULTS: Forty-eight out of 485 (9.89%) raw retail meat samples were contaminated with S. aureus. Raw retail buffalo meat (16%) had the highest incidence of S. aureus, while raw camel meat (4%) had the lowest. S. aureus bacteria exhibited the uppermost incidence of resistance toward tetracycline (79.16%), penicillin (72.91%), gentamicin (60.41%), and doxycycline (41.666%). The incidence of resistance toward chloramphenicol (8.33%), levofloxacin (22.91%), rifampin (22.91%), and azithromycin (25%) was lower than other examined antibiotics. The most routinely detected antibiotic resistance genes were blaZ (58.33%), tetK (52.08%), aacA-D (33.33%), and ermA (27.08%). Cat1 (4.16%), rpoB (10.41%), msrA (12.50%), grlA (12.50%), linA (14.58%), and dfrA1 (16.66%) had the lower incidence rate. CONCLUSION: Raw meat of animals may be sources of resistant S. aureus which pose a hygienic threat about the consumption of raw meat. Nevertheless, further investigations are essential to understand supplementary epidemiological features of S. aureus in retail meat.202032440171
1265110.9565Coagulase-negative staphylococci (CoNS) isolated from ready-to-eat food of animal origin--phenotypic and genotypic antibiotic resistance. The aim of this work was to study the pheno- and genotypical antimicrobial resistance profile of coagulase negative staphylococci (CoNS) isolated from 146 ready-to-eat food of animal origin (cheeses, cured meats, sausages, smoked fishes). 58 strains were isolated, they were classified as Staphylococcus xylosus (n = 29), Staphylococcus epidermidis (n = 16); Staphylococcus lentus (n = 7); Staphylococcus saprophyticus (n = 4); Staphylococcus hyicus (n = 1) and Staphylococcus simulans (n = 1) by phenotypic and genotypic methods. Isolates were tested for resistance to erythromycin, clindamycin, gentamicin, cefoxitin, norfloxacin, ciprofloxacin, tetracycline, tigecycline, rifampicin, nitrofurantoin, linezolid, trimetoprim, sulphamethoxazole/trimethoprim, chloramphenicol, quinupristin/dalfopristin by the disk diffusion method. PCR was used for the detection of antibiotic resistance genes encoding: methicillin resistance--mecA; macrolide resistance--erm(A), erm(B), erm(C), mrs(A/B); efflux proteins tet(K) and tet(L) and ribosomal protection proteins tet(M). For all the tet(M)-positive isolates the presence of conjugative transposons of the Tn916-Tn1545 family was determined. Most of the isolates were resistant to cefoxitin (41.3%) followed by clindamycin (36.2%), tigecycline (24.1%), rifampicin (17.2%) and erythromycin (13.8%). 32.2% staphylococcal isolates were multidrug resistant (MDR). All methicillin resistant staphylococci harboured mecA gene. Isolates, phenotypic resistant to tetracycline, harboured at least one tetracycline resistance determinant on which tet(M) was most frequent. All of the isolates positive for tet(M) genes were positive for the Tn916-Tn1545 -like integrase family gene. In the erythromycin-resistant isolates, the macrolide resistance genes erm(C) or msr(A/B) were present. Although coagulase-negative staphylococci are not classical food poisoning bacteria, its presence in food could be of public health significance due to the possible spread of antibiotic resistance.201525475289
1300120.9564Genotypic and Phenotypic-Based Assessment of Antibiotic Resistance and Profile of Staphylococcal Cassette Chromosome mec in the Methicillin-Resistant Staphylococcus aureus Recovered from Raw Milk. BACKGROUND: Multidrug resistant methicillin-resistant Staphylococcus aureus (MRSA) bacteria are determined to be one of the chief causes of foodborne diseases around the world. PURPOSE: This research was done to assess the genotypic and phenotypic profiles of antibiotic resistance and distribution of Staphylococcus cassette chromosome mec (SCCmec) types amongst the MRSA bacteria recovered from raw milk. METHODS: Five-hundred and ninety raw milk samples were collected and examined. MRSA bacteria were recognized using susceptibility evaluation toward oxacillin and cefoxitin disks. Profile of antibiotic resistance genes and SCCmec types were determined using the PCR. Antibiotic resistance pattern of isolates was examined using the disk diffusion. RESULTS: Thirty-nine out of 590 raw milk samples (6.61%) were positive for S. aureus. Twenty-eight out of 39 (71.79%) bacteria were defined as MRSA bacteria. Raw buffalo (80%) milk samples had the maximum incidence of MRSA, while raw camel (33.33%) had the minimum. MRSA bacteria harbored the maximum incidence of resistance toward penicillin (100%), tetracycline (100%), erythromycin (82.14%), gentamicin (78.57%) and trimethoprim-sulfamethoxazole (78.57%). Incidence of resistance toward more than eight classes of antibiotic agents was 28.57%. The most frequently distinguished antibiotic resistance markers were blaZ (100%), tetK (85.71%), dfrA1 (71.42%), aacA-D (67.85%), ermA (50%) and gyrA (42.85%). SCCmec IVa (29.62%), V (25%), III (14.81%) and IVb (11.11%) were the most frequently distinguished types. CONCLUSION: Raw milk of dairy animals maybe sources of multidrug resistant MRSA which pose a hygienic threat concerning the consumption of raw milk in Iran. Nevertheless, further investigations are necessary to understand supplementary epidemiological features of MRSA in raw milk.202032099419
2410130.9564Phenotypic and molecular characterization of antimicrobial resistance in Trueperella pyogenes strains isolated from bovine mastitis and metritis. BACKGROUND: Trueperella pyogenes is one of the most clinically imperative bacteria responsible for severe cases of mastitis and metritis, particularly in postpartum dairy cows. The bacterium has emergence of antibiotic resistance and virulence characters. The existing research was done to apprise the phenotypic and genotypic evaluation of antibiotic resistance and characterization of virulence factors in the T. pyogenes bacteria of bovine mastitis and metritis in postpartum cows. METHODS: Two-hundred and twenty-six bovine mastitic milk and 172 uterine swabs were collected and transferred to laboratory. Samples were cultured and T. pyogenes isolates were subjected to disk diffusion and DNA extraction. Distribution of virulence and antibiotic resistance genes was studied by PCR. RESULTS: Thirty-two out of 226 (14.15%) mastitic milk and forty-one out of 172 (23.83%) uterine swab samples were positive for T. pyogenes. Isolates of mastitic milk harbored the highest prevalence of resistance toward gentamicin (100%), penicillin (100%), ampicillin (90.62%), amoxicillin (87.50%) and trimethoprim-sulfamethoxazole (87.50%), while those of metritis harbored the highest prevalence of resistance toward ampicillin (100%), amoxicillin (100%), gentamicin (97.56%), penicillin (97.56%) and cefalexin (97.56%). AacC, aadA1, aadA2 and tetW were the most generally perceived antibiotic resistance genes. All bacteria harbored plo (100%) and fimA (100%) virulence factors. NanP, nanH, fimC and fimE were also the most generally perceived virulence factors. CONCLUSIONS: All bacteria harbored plo and fimA virulence factors which showed that they can use as specific genetic markers with their important roles in pathogenicity of T. pyogenes bacteria. Phenotypic pattern of antibiotic resistance was confirmed by genotypic characterization of antibiotic resistance genes.201931881834
1266140.9562Characterization of methicillin-resistant coagulase-negative staphylococci in milk from cows with mastitis in Brazil. Staphylococci are one of the most prevalent microorganisms in bovine mastitis. Staphylococcus spp. are widespread in the environment, and can infect animals and humans as opportunistic pathogens. The objective of this study was to determine the frequency of methicillin-resistance (MR) among coagulase-negative staphylococci (CoNS) previously obtained from milk of mastitic cows in Brazil and to characterize the antimicrobial resistance phenotype/genotype and the SCCmec type of MRCoNS isolates. Identification of MRCoNS was based on both biochemical and molecular methods. Susceptibility testing for eleven antimicrobials was performed by disk-diffusion agar. Antimicrobial resistance genes and SCCmec were investigated by specific PCRs. Twenty-six MRCoNS were detected (20 % of total CoNS), obtained from 24 animals, and were identified as follows: S. epidermidis (7 isolates), S. chromogenes (7), S. warneri (6), S. hyicus (5) and S. simulans (1). All MRCoNS isolates carried mecA while the mecC gene was not detected in any CoNS. The SCCmec IVa was demonstrated in nine MRCoNS, while the remaining 17 isolates harbored non-typeable SCCmec cassettes. In addition to oxacillin and cefoxitin resistance, MRCoNS showed resistance to tetracycline (n = 7), streptomycin (n = 6), tobramycin (n = 6), and gentamicin (n = 4), and harbored the genes tet(K) (n = 7), str (n = 3), ant(4') (n = 6) and aac(6')-aph(2″) (n = 4), respectively. In addition, seven strains showed intermediate resistance to clindamycin and two to streptomycin, of which two harboured the lnu(B) and lsa(E) genes and two the aad(E) gene, respectively. One isolate presented intermediate erythromycin and clindamycin resistance and harbored an erm(C) gene with an uncommon 89-bp deletion rendering a premature stop codon. MRCoNS can be implicated in mastitis of cows and they constitute a reservoir of resistance genes that can be transferred to other pathogenic bacteria.201424817534
1299150.9562Prevalence, Drug Resistance, and Virulence Genes of Potential Pathogenic Bacteria in Pasteurized Milk of Chinese Fresh Milk Bar. Fresh Milk Bar (FMB), an emerging dairy retail franchise, is used to instantly produce and sell pasteurized milk and other dairy products in China. However, the quality and safety of pasteurized milk in FMB have received little attention. The objective of this study was to investigate the prevalence, antimicrobial resistance, and virulence genes of Escherichia coli, Staphylococcus aureus, and Streptococcus in 205 pasteurized milk samples collected from FMBs in China. Four (2.0%) isolates of E. coli, seven (3.4%) isolates of S. aureus, and three (1.5%) isolates of Streptococcus agalactiae were isolated and identified. The E. coli isolates were resistant to amikacin (100%), streptomycin (50%), and tetracycline (50%). Their detected resistance genes include aac(3)-III (75%), blaTEM (25%), aadA (25%), aac(3)-II (25%), catI (25%), and qnrB (25%). The S. aureus isolates were mainly resistant to penicillin G (71.4%), trimethoprim-sulfamethoxazole (71.4%), kanamycin (57.1%), gentamicin (57.1%), amikacin (57.1%), and clindamycin (57.1%). blaZ (42.9%), mecA (28.6%), ermB (14.3%), and ermC (14.3%) were detected as their resistance genes. The Streptococcus strains were mainly resistant to tetracycline (66.7%) and contained the resistance genes pbp2b (33.3%) and tetM (33.3%). The virulence genes eae and stx2 were only found in one E. coli strain (25%), sec was detected in two S. aureus strains (28.6%), and bca was detected in one S. agalactiae strain (33.3%). The results of this study indicate that bacteria with drug resistance and virulence genes isolated from the pasteurized milk of FMB are a potential risk to consumers' health.202134129676
1264160.9561Characterization of mannitol-fermenting methicillin-resistant staphylococci isolated from pigs in Nigeria. This study was conducted to determine the species distribution, antimicrobial resistance pheno- and genotypes and virulence traits of mannitol-positive methicillin-resistant staphylococci (MRS) isolated from pigs in Nsukka agricultural zone, Nigeria. Twenty mannitol-positive methicillin-resistant coagulase-negative staphylococcal (MRCoNS) strains harboring the mecA gene were detected among the 64 Staphylococcus isolates from 291 pigs. A total of 4 species were identified among the MRCoNS isolates, namely, Staphylococcus sciuri (10 strains), Staphylococcus lentus (6 strains), Staphylococcus cohnii (3 strains) and Staphylococcus haemolyticus (one strain). All MRCoNS isolates were multidrug-resistant. In addition to β-lactams, the strains were resistant to fusidic acid (85%), tetracycline (75%), streptomycin (65%), ciprofloxacin (65%), and trimethoprim/sulphamethoxazole (60%). In addition to the mecA and blaZ genes, other antimicrobial resistance genes detected were tet(K), tet(M), tet(L), erm(B), erm(C), aacA-aphD, aphA3, str, dfrK, dfrG, cat pC221, and cat pC223. Thirteen isolates were found to be ciprofloxacin-resistant, and all harbored a Ser84Leu mutation within the QRDR of the GyrA protein, with 3 isolates showing 2 extra substitutions, Ser98Ile and Arg100Lys (one strain) and Glu88Asp and Asp96Thr (2 strains). A phylogenetic tree of the QRDR nucleotide sequences in the gyrA gene revealed a high nucleotide diversity, with several major clusters not associated with the bacterial species. Our study highlights the possibility of transfer of mecA and other antimicrobial resistance genes from MRCoNS to pathogenic bacteria, which is a serious public health and veterinary concern.201526413075
5385170.9559Environmental heterogeneity of Staphylococcus species from alkaline fermented foods and associated toxins and antimicrobial resistance genetic elements. Different samples of three products including Bikalga and Soumbala from Burkina Faso (West Africa) and Ntoba Mbodi from Congo-Brazzaville (Central Africa) were evaluated. The bacteria (400) were phenotyped and genotypically characterized by Rep-PCR, PFGE, 16S rRNA and rpoB gene sequencing and spa typing. Their PFGE profiles were compared with those of 12,000 isolates in the Center for Disease Control (CDC, USA) database. They were screened for the production of enterotoxins, susceptibility to 19 antimicrobials, presence of 12 staphylococcal toxin and 38 AMR genes and the ability to transfer erythromycin and tetracycline resistance genes to Enterococcus faecalis JH2-2. Fifteen coagulase negative (CoNS) and positive (CoPS) species characterized by 25 Rep-PCR/PFGE clusters were identified: Staphylococcus arlettae, S. aureus, S. cohnii, S. epidermidis, S. gallinarum, S. haemolyticus, S. hominis, S. pasteuri, S. condimenti, S. piscifermentans, S. saprophyticus, S. sciuri, S. simulans, S. warneri and Macrococcus caseolyticus. Five species were specific to Soumbala, four to Bikalga and four to Ntoba Mbodi. Two clusters of S. gallinarum and three of S. sciuri were particular to Burkina Faso. The S. aureus isolates exhibited a spa type t355 and their PFGE profiles did not match any in the CDC database. Bacteria from the same cluster displayed similar AMR and toxin phenotypes and genotypes, whereas clusters peculiar to a product or a location generated distinct profiles. The toxin genes screened were not detected and the bacteria did not produce the staphylococcal enterotoxins A, B, C and D. AMR genes including blazA, cat501, dfr(A), dfr(G), mecA, mecA1, msr(A) and tet(K) were identified in CoNS and CoPS. Conjugation experiments produced JH2-2 isolates that acquired resistance to erythromycin and tetracycline, but no gene transfer was revealed by PCR. The investigation of the heterogeneity of Staphylococcus species from alkaline fermented foods, their relationship with clinical and environmental isolates and their safety in relation to antimicrobial resistance (AMR) and toxin production is anticipated to contribute to determining the importance of staphylococci in alkaline fermented foods, especially in relation to the safety of the consumers.201931670141
1276180.9559Should we leave the paper currency? A microbiological examination. OBJECTIVE: Pathogens can be transmitted to banknotes due to the personal unhygienic habits. The aim of study was to find the possible pathogens on the banknotes circulating in the market and also to present their antibacterial resistance and their various virulence factors using genotypic and phenotypic methods. METHODS: A total of 150 samples of bank-notes were randomly collected between August 2017 and March 2018. VITEK systems were used for identification and antimicrobial susceptibility testing respectively. Antimicrobial resistance genes (mecA, van, extended-spectrum β-lactamase [ESBL] and carbapenemases) and staphyloccoccal virulence genes (staphyloccoccal enterotoxins [SEs], pvl, and tsst-1) were determined using with real-time PCR. RESULTS: Staphylococcus aureus, coagulase-negative staphylococci (CoNS), Enterococcus spp., Gram-negative enteric bacteria, non-fermentative Gram-negative bacteria and Candida spp. were detected 48%, 54.7%, 56%, 21.3%, 18.7%, and 4%, respectively. Methicillin-resistant S. aureus, vancomycin-resistant enterococci and ESBL producing Gram-negative were found 46.8%, 1.3%, and 28.7%, respectively. Pvl, tsst-1, and SEs genes were found in a 2.8/4.9%, 1.4/1.2%, and 100/ 87.8% of the S. aureus/CoNS strains, respectively. The sea gene was found the most common enterotoxigenic gene. blaTEM, blaSHV, blaCTX-M-2, blaCTX-M-1, blaKPC, and blaOXA-48 were found 55.8%, 46.5%, 41.2%, 18.6%, 18.6%, and 18.6%, respectively in Gram-negative strains. CONCLUSIONS: These results is very important to highlight hygienic status of paper currencies. This can be considered as an indication that banknotes may contribute to the spread of pathogens and antimicrobial resistance. Therefore, we may need to start using alternative products instead of banknotes.202032066229
1332190.9558First study on capsular serotypes and virulence factors of Pasteurella multocida isolates from Phan Rang sheep in Vietnam. BACKGROUND AND AIM: Pasteurella multocida is considered as a main factor mediating pneumonic pasteurellosis in ruminants, including sheep. It is also a current threat to Phan Rang sheep in Vietnam. This study aimed to characterize P. multocida isolated from Phan Rang sheep, their antibiotic resistance profile, and the prevalence of some virulence-associated genes of these strains. MATERIALS AND METHODS: Bacteria were isolated on brain heart infusion, 10% sheep blood agar plates, and screened by biochemical tests. The polymerase chain reaction technique was used with specific primers to identify P. multocida, the presence of virulence-associated genes, and serotypes of isolates. Antimicrobial susceptibility and biofilm formation of isolates were examined using the disk diffusion method and crystal violet-based method, respectively. RESULTS: A total of 41 P. multocida strains were isolated from 485 samples from clinically sick and healthy sheep. Of the isolates, 58.53% were serotype A, 9.75% were serotype B, and 31.71% were serotype D. Healthy animals were infected with serotype D only. All 15 virulence genes were identified in all strains isolated from clinically sick sheep, while strains isolated from healthy sheep carried 11/15 virulence genes tested. Among virulence-associated genes exbB, exbD, tonB, ompA, oma87, fimA, hgbA, and nanB were detected in over 90% of isolates, whereas hgbB, nanH, tbpA and pfhA were less frequent. Interestingly, pmHAS and tadD were highly prevalent in capsular type A strains, whereas the toxA gene was detected in capsular type D strains only. All of the isolated strains were fully susceptible to enrofloxacin, ciprofloxacin, neomycin, and ofloxacin. About 92.68% were susceptible to chloramphenicol and 90.24% to amikacin, but there was high resistance to erythromycin, tetracycline, and amoxicillin. Our results reveal that 53.65% of 41 isolates could produce biofilm, whereas 46.34% could not. CONCLUSION: Pasteurella multocida from Phan Rang sheep possess many virulence genes and resistance to several common antibiotics such as erythromycin, tetracycline, and amoxicillin. The results are an important warning regarding antibiotic resistance of P. multocida.202337042011