# | Rank | Similarity | Title + Abs. | Year | PMID |
|---|---|---|---|---|---|
| 0 | 1 | 2 | 3 | 4 | 5 |
| 1283 | 0 | 1.0000 | Antimicrobial 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. | 2023 | 37998777 |
| 1282 | 1 | 0.9998 | Subclinical 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. | 2021 | 34072543 |
| 2680 | 2 | 0.9998 | Antimicrobial Resistance, Biofilm Formation, and Virulence Genes in Enterococcus Species from Small Backyard Chicken Flocks. Backyard birds are small flocks that are more common in developing countries. They are used for poultry meat and egg production. However, they are also implicated in the maintenance and transmission of several zoonotic diseases, including multidrug-resistant bacteria. Enterococci are one of the most common zoonotic bacteria. They colonize numerous body sites and cause a wide range of serious nosocomial infections in humans. Therefore, the objective of the present study was to investigate the diversity in Enterococcus spp. in healthy birds and to determine the occurrence of multidrug resistance (MDR), multi-locus sequence types, and virulence genes and biofilm formation. From March 2019 to December 2020, cloacal swabs were collected from 15 healthy backyard broiler flocks. A total of 90 enterococci strains were recovered and classified according to the 16S rRNA sequence into Enterococcus faecalis (50%); Enterococcus faecium (33.33%), Enterococcus hirae (13.33%), and Enterococcus avium (3.33%). The isolates exhibited high resistance to tetracycline (55.6%), erythromycin (31.1%), and ampicillin (30%). However, all of the isolates were susceptible to linezolid. Multidrug resistance (MDR) was identified in 30 (33.3%) isolates. The enterococci AMR-associated genes ermB, ermA, tetM, tetL, vanA, cat, and pbp5 were identified in 24 (26.6%), 11 (12.2%), 39 (43.3%), 34 (37.7%), 1 (1.1%), 4 (4.4%), and 23 (25.5%) isolates, respectively. Of the 90 enterococci, 21 (23.3%), 27 (30%), and 36 (40%) isolates showed the presence of cylA, gelE, and agg virulence-associated genes, respectively. Seventy-three (81.1%) isolates exhibited biofilm formation. A statistically significant correlation was obtained for biofilm formation versus the MAR index and MDR. Multi-locus sequence typing (MLST) identified eleven and eight different STs for E. faecalis and E. faecium, respectively. Seven different rep-family plasmid genes (rep1-2, rep3, rep5-6, rep9, and rep11) were detected in the MDR enterococci. Two-thirds (20/30; 66.6%) of the enterococci were positive for one or two rep-families. In conclusion, the results show that healthy backyard chickens could act as a reservoir for MDR and virulent Enterococcus spp. Thus, an effective antimicrobial stewardship program and further studies using a One Health approach are required to investigate the role of backyard chickens as vectors for AMR transmission to humans. | 2022 | 35326843 |
| 1287 | 3 | 0.9998 | Frequently used therapeutic antimicrobials and their resistance patterns on Staphylococcus aureus and Escherichia coli in mastitis affected lactating cows. Mastitis is one of the most frequent and costly production diseases of dairy cattle. It is frequently treated with broad-spectrum antimicrobials. The objectives of this work were to investigate the prevalence of Staphylococcus aureus and Escherichia coli, find out the antimicrobials used in mastitis treatment, and explore the antimicrobial resistance profile including detection of resistance genes. Bacterial species and antimicrobial resistance genes were confirmed by the polymerase-chain reaction. A total of 450 cows were screened, where 23 (5.11%) and 173 (38.44%) were affected with clinical and sub-clinical mastitis, respectively. The prevalence of S. aureus was 39.13% (n = 9) and 47.97%(n = 83) while, E. coli was 30.43% (n = 7) and 15.60% (n = 27) in clinical and sub-clinical mastitis affected cows, respectively. The highest antimicrobials used for mastitis treatment were ciprofloxacin (83.34%), amoxycillin (80%) and ceftriaxone (76.67%). More than, 70% of S. aureus showed resistance against ampicillin, oxacillin, and tetracycline and more than 60% of E. coli exhibited resistance against oxacillin and sulfamethoxazole-trimethoprim. Selected antimicrobial resistance genes (mecA, tetK, tetL, tetM, tetA, tetB, tetC, sul1, sul2 and sul3) were identified from S. aureus and E. coli. Surprisingly, 7 (7.61%) S. aureus carried the mecA gene and were confirmed as methicillin-resistant S. aureus (MRSA). The most prevalent resistance genes were tetK 18 (19.57%) and tetL 13 (14.13%) for S. aureus, whereas sul1 16 (47.06%), tetA 12 (35.29%), sul2 11 (32.35%) and tetB 7 (20.59%) were the most common resistance genes in E. coli. Indiscriminate use of antimicrobials and the presence of multidrug-resistant bacteria suggest a potential threat to public health. | 2022 | 35291582 |
| 1286 | 4 | 0.9998 | High prevalence of antibiotic resistance in pathogenic foodborne bacteria isolated from bovine milk. This study aimed to investigate the prevalence of foodborne pathogenic bacteria in bovine milk, their antibiogram phenotype, and the carriage of antibiotic resistance genes. Raw bovine milk samples (n = 100) were randomly collected from different suppliers in the northwest of Iran. Antibiotic-resistant patterns and the presence of antibiotic resistance genes were evaluated in the isolates. Escherichia coli, Listeria monocytogenes, Staphylococcus aureus, and Salmonella spp. were isolated from 78%, 47%, 25%, and 21% of samples, respectively. All isolates showed high rates of resistance to amoxicillin, penicillin, and cefalexin. The bla(TEM) and bla(SHV) genes were detected in 50.0% and 6.4% of E. coli isolates, respectively. Also, 28.5% and 19.0% of Salmonella isolates were positive for bla(TEM) and bla(SHV). The frequency of mecA and bla(Z) in S. aureus isolates was 20.0% and 12.0%, respectively. The high prevalence of bovine milk contamination with antimicrobial-resistant species in this study necessitates precise control on antibiotic prescription in veterinary medicine. | 2022 | 35264647 |
| 2358 | 5 | 0.9998 | Genotypic and Phenotypic Evaluation of Biofilm Production and Antimicrobial Resistance in Staphylococcus aureus Isolated from Milk, North West Province, South Africa. Background: Biofilm formation in S. aureus may reduce the rate of penetration of antibiotics, thereby complicating treatment of infections caused by these bacteria. The aim of this study was to correlate biofilm-forming potentials, antimicrobial resistance, and genes in S. aureus isolates. Methods: A total of 64 milk samples were analysed, and 77 S. aureus were isolated. Results: Seventy (90.9%) isolates were biofilm producers. The ica biofilm-forming genes were detected among 75.3% of the isolates, with icaA being the most prevalent (49, 63.6%). The icaB gene was significantly (P = 0.027) higher in isolates with strong biofilm formation potentials. High resistance (60%-90%) of the isolates was observed against ceftriaxone, vancomycin, and penicillin, and 25 (32.5%) of S. aureus showed multidrug resistance (MDR) to at least three antibiotics. Five resistance genes, namely blaZ (29, 37.7%), vanC (29, 37.7%), tetK (24, 31.2%), tetL (21, 27.3%), and msrA/B (16, 20.8%) were detected. Most MDR phenotypes possessed at least one resistance gene alongside the biofilm genes. However, no distinct pattern was identified among the resistance and biofilm phenotypes. Conclusions: The high frequency of potentially pathogenic MDR S. aureus in milk samples intended for human consumption, demonstrates the public health relevance of this pathogen in the region. | 2020 | 32252278 |
| 1280 | 6 | 0.9998 | Antimicrobial-Resistant Staphylococcus spp. Harbored by Hedgehogs (Erinaceus europaeus) in Central Italy. BACKGROUND/OBJECTIVES: European hedgehogs (Erinaceus europaeus) are present in areas where there is human activity; therefore, they can be a source of pathogens for other animals and humans. METHODS: Eighteen hedgehog carcasses were collected and analyzed for Staphylococcus spp. Isolated strains were typed and analyzed for exfoliative toxins genes and the phenotypic and genotypic characteristics of antimicrobial resistance. RESULTS: A total of 54 strains were isolated and typed as S. aureus, S. xylosus, S. sciuri, S. pseudintermedius, S. simulans, S. chromogenes, S. epidermidis, S. hyicus, and S. lentus. No strains had the eta and etb genes coding for exfoliative toxins. Overall, 39/54 (72.20%) isolates showed phenotypic resistance to at least one antimicrobial and 21/54 (38.80%) showed more than one resistance. The lowest efficacy was observed for erythromycin, with 40/54 (74.08%) strains classified as intermediate and 6/54 (11.11%) classified as resistant. Among the 29 isolates shown to be penicillin-resistant, 11 (37.93%) were oxacillin-resistant, with a minimum inhibitory concentration (MIC). Among the 54 staphylococcal strains, 2 (3.70%) were resistant to vancomycin, both with an MIC value equal to the maximum concentration of the antibiotic tested (256 μg/mL) and 2 (3.70%) had an intermediate resistance profile with an 8 μg/mL MIC value. No strains had the genes vanA and vanB. Two of the 29 (6.90%) penicillin-resistant strains had the blaZ gene; 8 (27.13%) strains had the mecA gene. Overall, 2/54 (3.70%) isolates were classified as extensively drug-resistant (XDR) and 9/54 (16.66%) were classified as multidrug-resistant (MDR). CONCLUSIONS: Hedgehogs can harbor antimicrobial-resistant staphylococci and can be sources of these bacteria for other animals and humans. They can also serve as bioindicators of the pathogens and antimicrobial-resistant bacteria circulating in a given habitat. | 2025 | 40724026 |
| 2377 | 7 | 0.9998 | Multidrug-resistant and enterotoxigenic methicillin-resistant Staphylococcus aureus isolated from raw milk of cows at small-scale production units. OBJECTIVE: Staphylococcus aureus (S. aureus) has evolved as one of the most significant bacteria causing food poisoning outbreaks worldwide. This study was carried out to investigate the prevalence, antibiotic sensitivity, virulence, and enterotoxin production of S. aureus in raw milk of cow from small-scale production units and house-raised animals in Damietta governorate, Egypt. MATERIAL AND METHODS: The samples were examined bacteriologically, and antimicrobial sensitivity testing was carried out. Moreover, isolates were characterized by the molecular detection of antimicrobial resistance, virulence, and enterotoxin genes. RESULTS: Out of 300 milk samples examined, S. aureus was isolated from 50 samples (16.7%). Antibiotic sensitivity testing revealed that isolates were resistant to β-lactams (32%), tetracycline (16%), and norfloxacin (16%); however, they showed considerable sensitivity to ceftaroline and amikacin (72%). Multidrug-resistance (MDR) has been observed in eight isolates (16%), with a MDR index (0.5) in all of them. Of the total S. aureus isolates obtained, methicillin-resistant S. aureus (MRSA) has been confirmed molecularly in 16/50 (32%) and was found to carry mecA and coa genes, while virulence genes; hlg (11/16, 68.75%) and tsst (6/16, 37.5%) were amplified at a lower percentage, and they showed a significant moderate negative correlation (r = -0.59, p-value > 0.05). Antibiotic resistance genes have been detected in resistant isolates relevant to their phenotypic resistance: blaZ (100%), tetK (50%), and norA (50%). Fifty percent of MRSA isolates carried the seb enterotoxin gene. CONCLUSION: High detection rate of MRSA and MDR isolates from milk necessitates the prompt implementation of efficient antimicrobial stewardship guidelines, especially at neglected small-scale production units. | 2022 | 35445112 |
| 2681 | 8 | 0.9998 | Determination of the Prevalence and Antimicrobial Resistance of Enterococcus faecalis and Enterococcus faecium Associated with Poultry in Four Districts in Zambia. The presence of antimicrobial-resistant Enterococci in poultry is a growing public health concern worldwide due to its potential for transmission to humans. The aim of this study was to determine the prevalence and patterns of antimicrobial resistance and to detect drug-resistant genes in Enterococcus faecalis and E. faecium in poultry from four districts in Zambia. Identification of Enterococci was conducted using phenotypic methods. Antimicrobial resistance was determined using the disc diffusion method and antimicrobial resistance genes were detected using polymerase chain reaction and gene-specific primers. The overall prevalence of Enterococci was 31.1% (153/492, 95% CI: 27.1-35.4). Enterococcus faecalis had a significantly higher prevalence at 37.9% (58/153, 95% CI: 30.3-46.1) compared with E. faecium, which had a prevalence of 10.5% (16/153, 95% CI: 6.3-16.7). Most of the E. faecalis and E. faecium isolates were resistant to tetracycline (66/74, 89.2%) and ampicillin and erythromycin (51/74, 68.9%). The majority of isolates were susceptible to vancomycin (72/74, 97.3%). The results show that poultry are a potential source of multidrug-resistant E. faecalis and E. faecium strains, which can be transmitted to humans. Resistance genes in the Enterococcus species can also be transmitted to pathogenic bacteria if they colonize the same poultry, thus threatening the safety of poultry production, leading to significant public health concerns. | 2023 | 37107019 |
| 2679 | 9 | 0.9998 | Detection and Molecular Characterization of Staphylococci from Eggs of Household Chickens. Eggs are a healthy and nutritious food source, but may be contaminated by bacteria. Previous studies have reported the presence of staphylococci in eggs of farmed chickens, but no study has evaluated the staphylococcal population of eggs from household chickens. In this study, staphylococci from eggs (n = 275) of household chickens collected from November 2016 to March 2017 from different villages of Khyber Pakhtunkhwa province, Pakistan, were characterized. Seven species of staphylococci were identified from 65 eggs, including the predominant species, Staphylococcus xylosus (49/275; 17.8%). S. xylosus isolates (n = 73) were tested for antimicrobial susceptibility, presence of resistance genes, genetic relatedness, and inhibitory activity against other bacteria. The majority of isolates were resistant to oxacillin (83.6%) and tetracycline (24.7%), but also exhibited resistance to daptomycin and linezolid (5.5% each). Of the 10 resistance genes tested, isolates were only positive for mecA (35.6%; 26/73), mecC/C1 (2.7%; 2/73), and tet(K) (14/73; 19%). Using pulsed-field gel electrophoresis (PFGE), nine clusters had identical PFGE patterns. Isolates produced inhibitory activity against a broad spectrum of bacteria; 20.5%, 19.2%, 17.8%, and 16.4% of S. xylosus were able to inhibit growth of Salmonella enterica serotype Typhi, methicillin-susceptible Staphylococcus aureus, Escherichia coli, and methicillin-resistant Staphylococcus aureus, respectively. This study demonstrated the presence of genetically related antimicrobial-resistant S. xylosus from eggs from household chickens. Like table eggs, eggs of household chickens also contain staphylococci that may be resistant to antimicrobials used to treat human infections. These data will allow comparison between staphylococci from eggs from different sources and may indicate the relative safety of eggs from household chickens. Further study of these egg types and their microbial composition is warranted. | 2019 | 31009262 |
| 1279 | 10 | 0.9998 | Antibiotic resistance and virulence potentials of E. faecalis and E. faecium in hospital wastewater: a case study in Ardabil, Iran. Hospital wastewater can contaminate the environment with antibiotic-resistant and virulent bacteria. We analyzed wastewater samples from four hospitals in Ardabil province, Iran for Enterococcus faecium and Enterococcus faecalis using culture and molecular methods. We also performed antimicrobial susceptibility testing and polymerase chain reaction testing for resistance and virulence genes. Out of 141 enterococci isolates, 68.8% were E. faecium and 23.4% were E. faecalis. Ciprofloxacin and rifampicin showed the highest level of resistance against E. faecalis and E. faecium isolates at 65%. High-level gentamicin resistance (HLGR), high-level streptomycin resistance (HLSR), ampicillin, and vancomycin resistance were observed in 25, 5, 10, and 5.15% of E. faecium, and 15, 6, 15, and 3.03% of E. faecalis isolates, respectively. The ant(6')-Ia and ant(3')-Ia genes that were responsible for streptomycin resistance were observed in HLSR isolates and aph(3')-IIIa and aac(6') Ie-aph(2″)-Ia genes accounting for gentamicin resistance were detected in HLGR isolates. vanA was the predominant gene detected in vancomycin-resistant isolates. The majority of isolates were positive for gelE, asa1, esp, cylA, and hyl virulence genes. We found that drug-resistant and virulent E. faecalis and E. faecium isolates were prevalent in hospital wastewater. Proper treatment strategies are required to prevent their dissemination into the environment. | 2023 | 37756195 |
| 1289 | 11 | 0.9997 | Virulence factors and antibiotic resistance properties of Streptococcus species isolated from hospital cockroaches. Hospital cockroaches are probable sources of pathogenic bacteria. The present investigation was performed to assess the antibiotic resistance properties and distribution of virulence factors in the Streptococcus spp. isolated from hospital cockroaches. Six hundred and sixty cockroach samples were collected. Cockroaches were washed with normal saline, and the achieved saline was used for bacterial culture. Isolated Streptococcus spp. were subjected to disk diffusion. The distribution of virulence factors and antibiotic resistance genes were assessed using a polymerase chain reaction. The prevalence of S. pyogenes, S. agalactiae, and S. pneumonia amongst examined samples was 4.82%, 1.66%, and 6.96%, respectively. Cfb (53.93%), cyl (52.8%), scaa (51.68%) and glna (50.56%) were the most commonly detected virulence factors. Pbp2b (71.91%), pbp2x (58.42%), mefA (46.06%), ermB (46.06%) and tetM (46.06%) were the most commonly detected antibiotic resistance genes. Streptococcal spp. harbored the highest prevalence of resistance against tetracycline (80.89%), trimethoprim (65.16%), and penicillin (56.17%). To the best of our knowledge, this is the first prevalence report of virulence factors and antibiotic resistance genes in the Streptococcal spp. isolated from American, German, and oriental hospital cockroaches in Iran. Our findings indicated a certain role for cockroaches in nosocomial pathogens transmission in the hospital environment. | 2021 | 34194905 |
| 1285 | 12 | 0.9997 | Antimicrobial Resistance Profiles and Genes in Streptococcus uberis Associated With Bovine Mastitis in Thailand. Streptococcus uberis is recognized as an environmental mastitis pathogen in dairy cattle. The varied success rate of antibiotic treatment for S. uberis intramammary infection may be associated with the antimicrobial resistance (AMR) of these bacteria. This observational study aimed to analyze 228 S. uberis strains associated with bovine mastitis in northern Thailand from 2010 to 2017. AMR and AMR genes were determined by the minimum inhibitory concentration (MIC) using a microdilution method and polymerase chain reaction, respectively. The majority of S. uberis strains were resistant to tetracycline (187/228, 82.02%), followed by ceftiofur (44/228, 19.30%), and erythromycin (19/228, 8.33%). The MIC50 and MIC90 of ceftiofur in 2017 were 2-4-fold higher than those in 2010 (P < 0.01). Resistance to tetracycline and ceftiofur significantly increased between 2010 and 2017 (P < 0.05). The most common gene detected in S. uberis was tetM (199/228, 87.28%), followed by ermB (151/228, 66.23 %) and blaZ (15/228, 6.58 %). The association between tetracycline resistance and tetM detection was statistically significant (P < 0.01). The detection rates of tetM significantly increased, while the detection rates of tetO and ermB significantly decreased during 2010-2017. AMR monitoring for bovine mastitis pathogens, especially S. uberis, is necessary to understand the trend of AMR among mastitis pathogens, which can help create an AMR stewardship program for dairy farms in Thailand. | 2021 | 34485432 |
| 2658 | 13 | 0.9997 | Rapid detection of major enterotoxin genes and antibiotic resistance of Staphylococcus aureus isolated from raw milk in the Yazd province, Iran. INTRODUCTION: Raw milk is a nutrient-rich food, but it may harbour harmful bacteria, such as enterotoxigenic Staphylococcus aureus (S. aureus), which can cause staphylococcal food poisoning. Antibiotic resistance of S. aureus in raw milk can increase the risk of such infections, particularly among susceptible individuals. OBJECTIVE: This study aimed to investigate the prevalence of enterotoxin genes a, d, g, i and j and the antibiotic resistance of S. aureus isolated from raw milk samples. METHODS: During a 6-month sampling period, 60 raw milk specimens were obtained from diverse locations in Yazd province, Iran. Antibiogram profiling was conducted via the disc diffusion method. In addition, staphylococcal enterotoxin (SE) genes a, d, g, i, and j were detected through real-time PCR analysis. RESULTS: Bacteriological assays confirmed the presence of S. aureus in 11 samples (18.3%). All isolates demonstrated 100% resistance to penicillin G but exhibited sensitivity to vancomycin, while resistance to other antibiotics ranged from 36.4% to 45.5%. The prevalence of enterotoxin genes in these strains showed variable distribution, with sea being the predominant SE (45.5%), followed by sed (36.4%), seg (18.2), sej and sei (9.1% each). CONCLUSIONS: This study discovered the presence of multiple enterotoxins in S. aureus strains obtained from raw milk samples. These strains also demonstrated resistance to a variety of antibiotics. Since enterotoxigenic S. aureus is known to cause human food poisoning, monitoring food hygiene practices, especially during raw milk production, is critical. | 2024 | 38519836 |
| 1330 | 14 | 0.9997 | Antimicrobial resistance of Enterococcus spp. isolated from Thai fermented pork in Chiang Rai Province, Thailand. OBJECTIVES: The aim of this study was to evaluate the prevalence of antimicrobial-resistant phenotypes and genes of Enterococcus spp. in order to explore the range of resistance profiles from Thai traditional fermented pork. METHODS: A total of 120 Thai fermented pork specimens were collected in Chiang Rai, Thailand. Antimicrobial resistance among isolated enterococci to 11 antimicrobial agents was determined by the agar disk diffusion method. Antibiotic resistance genes from resistant phenotypes and virulence genes were observed. RESULTS: A total of 119 enterococci were found contaminating the collected samples. The most prevalent species was Enterococcus faecalis (68.9%), followed by Enterococcus hirae (16.0%), Enterococcus faecium (13.4%) and Enterococcus gallinarum (1.7%). The highest percentage of resistance was to ciprofloxacin (97.5%), followed by erythromycin (78.2%) and tetracycline (67.2%), whilst high-level gentamicin- and streptomycin-resistant isolates were of lower frequency (7.6% and 22.7%, respectively). All isolates were susceptible to the clinically important agents vancomycin and teicoplanin. Overall, a relatively high frequency of multidrug-resistant (MDR) enterococci was observed (76.2%). Antimicrobial-resistant phenotypes were found to carry aacA-aphD, addE, erm(B), mefA/E, cat, tet(L) and tet(M) resistance genes. Virulence genes were also evaluated and the gelE gene was found to be the most common (37.8%). CONCLUSIONS: These data highlight the importance of MDR enterococci in fermented pork in Thailand. This is the first report to detect the unusual species E. hirae carrying the mefA/E macrolide resistance gene. These clinically important and unusual enterococci isolates from Thai fermented pork could be a source of transferable resistance genes to other bacteria. | 2018 | 29030312 |
| 1300 | 15 | 0.9997 | Genotypic 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. | 2020 | 32099419 |
| 2673 | 16 | 0.9997 | Geographical and ecological analysis of resistance, coresistance, and coupled resistance to antimicrobials in respiratory pathogenic bacteria in Spain. A multicenter susceptibility surveillance (the S.A.U.C.E. project) including 2,721 Streptococcus pneumoniae, 3,174 Streptococcus pyogenes, and 2,645 Haemophilus influenzae consecutive isolates was carried out in 25 hospitals all over Spain from November 2001 to October 2002 to evaluate the current epidemiology of resistance of the main bacteria involved in community-acquired respiratory tract infections. Susceptibility testing was performed in a single centralized laboratory by a broth microdilution method. The prevalence of resistant S. pneumoniae strains was 0.4% for cefotaxime, 4.4% for amoxicillin and amoxicillin-clavulanic acid, 25.6% for cefuroxime-axetil, 34.5% for erythromycin, clarithromycin, and azithromycin, and 36.0% for cefaclor. Phenotypes of resistance to erythromycin were MLS(B) (macrolide-lincosamide-streptogramin B) in 89.9% (gene ermB) and M (macrolide) in 9.7% of cases (gene mefA). No strain harbored both genes simultaneously. Serotypes 19, 6, 23, 14, and 3 were the most prevalent, accounting for 54.6% of the total isolates. Resistance to macrolides seems to be the most alarming point, since among penicillin-susceptible isolates it reached 15.1% compared to 55.8% among penicillin-resistant strains. Geographically, a number of regions had rates of erythromycin resistance above 40% (even higher in children). Resistance to erythromycin was also high in S. pyogenes isolates: mean regional 33.2%, beta-lactamase-producing H. influenzae were 20%, whereas 4.4% had a beta-lactamase-negative, ampicillin-resistant phenotype. We highlight the importance of different geographical frequencies of coresistance (associations of resistance to different drugs within the same species) and coupled resistance (association of resistance between different species) probably resulting from different local coselective events. | 2005 | 15855520 |
| 2398 | 17 | 0.9997 | Antimicrobial-Resistant Enterococcus spp. in Wild Avifauna from Central Italy. Bacteria of the genus Enterococcus are opportunistic pathogens, part of the normal intestinal microflora of animals, able to acquire and transfer antimicrobial resistance genes. The aim of this study was to evaluate the possible role of wild avifauna as a source of antimicrobial-resistant enterococci. To assess this purpose, 103 Enterococcus spp. strains were isolated from the feces of wild birds of different species; they were tested for antimicrobial resistance against 21 molecules, vancomycin resistance, and high-level aminoglycosides resistance (HLAR). Furthermore, genes responsible for vancomycin, tetracycline, and HLAR were searched. E. faecium was the most frequently detected species (60.20% of isolates), followed by E. faecalis (34.95% of isolates). Overall, 99.02% of the isolated enterococci were classified as multidrug-resistant, with 19.41% extensively drug-resistant, and 2.91% possible pan drug-resistant strains. Most of the isolates were susceptible to amoxicillin/clavulanic acid (77.67%) and ampicillin (75.73%), with only 5.83% of isolates showing an ampicillin MIC ≥ 64 mg/L. HLAR was detected in 35.92% of isolates, mainly associated with the genes ant(6)-Ia and aac(6')-Ie-aph(2″)-Ia. Few strains (4.85%) were resistant to vancomycin, and the genes vanA and vanB were not detected. A percentage of 54.37% of isolates showed resistance to tetracycline; tet(M) was the most frequently detected gene in these strains. Wild birds may contribute to the spreading of antimicrobial-resistant enterococci, which can affect other animals and humans. Constant monitoring is essential to face up to the evolving antimicrobial resistance issue, and monitoring programs should include wild avifauna, too. | 2022 | 35884106 |
| 2397 | 18 | 0.9997 | Antimicrobial resistance in Enterococcus strains isolated from healthy domestic dogs. Enterococci are opportunistic bacteria that cause severe infections in animals and humans, capable to acquire, express, and transfer antimicrobial resistance. Susceptibility to 21 antimicrobial agents was tested by the disk diffusion method in 222 Enterococcus spp. strains isolated from the fecal samples of 287 healthy domestic dogs. Vancomycin and ampicillin minimum inhibitory concentrations (MICs) and high-level aminoglycoside resistance (HLAR) tests were also performed. Isolates showed resistance mainly to streptomycin (88.7%), neomycin (80.6%), and tetracycline (69.4%). Forty-two (18.9%) isolates showed an HLAR to streptomycin and 15 (6.7%) to gentamicin. Vancomycin and ampicillin MIC values showed 1 and 18 resistant strains, respectively. One hundred and thirty-six (61.2%) strains were classified as multidrug resistant and six (2.7%) strains as possibly extensively drug-resistant bacteria. Enterococcus faecium and Enterococcus faecalis were the most prevalent antimicrobial resistant species. Companion animals, which often live in close contact with their owners and share the same environment, represent a serious source of enterococci resistant to several antibiotics; for this reason, they may be a hazard for public health by providing a conduit for the entrance of resistance genes into the community. | 2017 | 27976593 |
| 2670 | 19 | 0.9997 | Molecular characterisation and antimicrobial resistance of Streptococcus agalactiae isolates from dairy farms in China. INTRODUCTION: Streptococcus agalactiae (S. agalactiae) is a pathogen causing bovine mastitis that results in considerable economic losses in the livestock sector. To understand the distribution and drug resistance characteristics of S. agalactiae from dairy cow mastitis cases in China, multilocus sequence typing (MLST) was carried out and the serotypes and drug resistance characteristics of the bacteria in the region were analysed. MATERIAL AND METHODS: A total of 21 strains of bovine S. agalactiae were characterised based on MLST, molecular serotyping, antimicrobial susceptibility testing, and the presence of drug resistance genes. RESULTS: The serotypes were mainly Ia and II, accounting for 47.6% and 42.9% of all serotypes, respectively. Five sequence types (STs) were identified through MLST. The ST103 and ST1878 strains were predominant, with rates of 52.4% and 28.6%, respectively. The latter is a novel, previously uncharacterised sequence type. More than 90% of S. agalactiae strains were susceptible to penicillin, oxacillin, cephalothin, ceftiofur, gentamicin, florfenicol and sulfamethoxazole. The bacteria showed high resistance to tetracycline (85.7%), clindamycin (52.1%) and erythromycin (47.6%). Resistant genes were detected by PCR, the result of which showed that 47.6%, 33.3% and 38.1% of isolates carried the tet(M), tet(O) and erm(B) genes, respectively. CONCLUSION: The results of this study indicate that S. agalactiae show a high level of antimicrobial resistance. It is necessary to monitor the pathogens of mastitis to prevent the transmission of these bacteria. | 2023 | 38143824 |