# | Rank | Similarity | Title + Abs. | Year | PMID |
|---|---|---|---|---|---|
| 0 | 1 | 2 | 3 | 4 | 5 |
| 2669 | 0 | 1.0000 | Occurrence of Pseudomonas lactis and Pseudomonas paralactis Amongst Non-Lactose-Fermenting Bacterial Isolates in Chickens and Their Antimicrobial Resistance Patterns. A serious concern of public-health proportion is rising from the carriage of antibiotic resistance determinant in Non-Lactose-Fermenting Bacteria and acquisition of virulence particularly in strains that are not routinely isolated or screened from common food animals. This study investigated the resistance profile and pathogenicity potential of selected Non-Lactose-Fermenting Bacteria isolated from 18 poultry farms. In total, we investigated the antibiotic susceptibility patterns of 25 Pseudomonas lactis and 71 Pseudomonas paralactis isolated from chicken faeces by testing them against 12 antibiotics. Resistance genes borne by the selected isolates were screened by sequencing the genetic location of resistance determinants was determined by plasmid curing. The virulence potential of the studied strains was determined phenotypically. Pseudomonas lactis isolates were mostly resistant to azetronam (93%), followed by trimethoprim (90%), cefotaxime (86%) and then amoxicillin/clavulanic acid (57%), while Pseudomonas paralactis. isolates were most resistant to azetronam (94%), trimethoprim (90%), cefepime (80%), piperacillin (75%) and amoxicillin/clavulanic acid (70%). The Multiple Antibiotic Resistance Index of Pseudomonas lactis and Pseudomonas paralactis isolates respectively ranged from 0.0 to 0.8 and 0.0 to 0.9. Polymerase Chain Reaction revealed the presence of antibiotic resistance factors such as blaCTX-M, qnrS, aac (6')-lb-cr and blaSHV while plasmid curing revealed carriages of resistance determinants on Resistance Plasmid. Moreover, virulence enzymes such as alkaline protease and phospholipase C were found in 3% and 12% of Pseudomonas paralactis and Pseudomonas lactis, respectively. This study reports the first occurrence of Pseudomonas lactis and Pseudomonas paralactis strains from chicken faeces, and their antimicrobial resistance and relative virulence suggest the encroachment of food animals by the under-studied non-lactose-fermenting bacteria that should alert public health concerns. | 2022 | 36329710 |
| 2702 | 1 | 0.9998 | Assessment of the presence of multidrug-resistant Escherichia coli, Salmonella and Staphylococcus in chicken meat, eggs and faeces in Mymensingh division of Bangladesh. The emergence of bacteria that is resistant to several drugs of clinical importance poses a threat to successful treatment, a phenomenon known as multidrug resistance that affects diverse classes of antibiotics. The purpose of this study was to evaluate the prevalence of multidrug-resistant Escherichia coli, Salmonella spp. and Staphylococcus aureus in chicken egg, meat and faeces from four districts of Bangladesh. A total of 120 chicken samples were collected from different poultry farms. Conventional culture and molecular detection methods were used for identification of bacterial isolates from the collected samples followed by antibiotic susceptibility test through the disc diffusion method, finally antibiotic resistant genes were detected by PCR. E. coli, Salmonella spp. and Staphylococcus aureus were detected in meat, egg and faecal samples. Antimicrobial susceptibility results revealed isolates from faeces were 100 % resistant to amoxicillin, while all S. aureus and Salmonella sp. from faeces were resistant to doxycycline, tetracycline and erythromycin. Salmonella spp. isolates from eggs indicated 100 % resistance to erythromycin, amoxycillin, while E. coli were 100 % resistant to erythromycin. E. coli and S. aureus from meat were 100 % resistant to amoxicillin and erythromycin. However, Salmonella spp. from eggs were 100 % susceptible to doxycycline, gentamicin, levofloxacin and tetracycline. The mecA and aac(3)-IV genes were only found in S. aureus and E. coli, respectively. The Sul1, tetB, and aadA1 were highest in Salmonella spp. and S. aureus, while the sul1, tetA and bla (SHV) were higher in E. coli. Isolates from all samples were multidrug resistant. These findings indicate a high risk of transmission of resistance genes from microbial contamination to food of animal origin. The study emphasizes the need for effective biosecurity measures, responsible antibiotic use, and strict regulations in poultry production to prevent the spread of antibiotic resistance. | 2024 | 39281621 |
| 1955 | 2 | 0.9998 | Phenotypic & genotypic study of antimicrobial profile of bacteria isolates from environmental samples. BACKGROUND & OBJECTIVES: The resistance to antibiotics in pathogenic bacteria has increased at an alarming rate in recent years due to the indiscriminate use of antibiotics in healthcare, livestock and aquaculture. In this context, it is necessary to monitor the antibiotic resistance patterns of bacteria isolated from the environmental samples. This study was conducted to determine the phenotypic and genotypic profile of antimicrobial resistance in Gram-negative bacteria isolated from environmental samples. METHODS: Two hundred and fifty samples were collected from different sources, viz. fish and fishery products (99), livestock wastes (81) and aquaculture systems (70), in and around Mangaluru, India. Isolation, identification and antimicrobial profiling were carried out as per standard protocols. The isolates were screened for the presence of resistance genes using PCR. RESULTS: A total of 519 Gram-negative bacteria comprising Escherichia coli (116), Salmonella spp. (14), Vibrio spp. (258), Pseudomonas spp. (56), Citrobacter spp. (26) and Proteus spp. (49) were isolated and characterized from 250 samples obtained from different sources. A total of 12 antibiotics were checked for their effectiveness against the isolates. While 31.6 per cent of the isolates were sensitive to all the antibiotics used, 68.4 per cent of the isolates showed resistance to at least one of the antibiotics used. One-third of the isolates showed multidrug resistance. Maximum resistance was observed for ampicillin (43.4%), followed by nitrofurantoin (20.8%). Least resistance was seen for carbapenems and chloramphenicol. PCR profiling of the resistant isolates confirmed the presence of resistance genes corresponding to their antibiotic profile. INTERPRETATION & CONCLUSIONS: This study results showed high rate of occurrence of antimicrobial resistance and their determinants in Gram-negative bacteria isolated from different environmental sources. | 2019 | 31219088 |
| 2681 | 3 | 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 |
| 2677 | 4 | 0.9998 | Detection of Staphylococcus Isolates and Their Antimicrobial Resistance Profiles and Virulence Genes from Subclinical Mastitis Cattle Milk Using MALDI-TOF MS, PCR and Sequencing in Free State Province, South Africa. Staphylococcus species are amongst the bacteria that cause bovine mastitis worldwide, whereby they produce a wide range of protein toxins, virulence factors, and antimicrobial-resistant properties which are enhancing the pathogenicity of these organisms. This study aimed to detect Staphylococcus spp. from the milk of cattle with subclinical mastitis using MALDI-TOF MS and 16S rRNA PCR as well as screening for antimicrobial resistance (AMR) and virulence genes. Our results uncovered that from 166 sampled cows, only 33.13% had subclinical mastitis after initial screening, while the quarter-level prevalence was 54%. Of the 50 cultured bacterial isolates, MALDI-TOF MS and 16S rRNA PCR assay and sequencing identified S. aureus as the dominant bacteria by 76%. Furthermore, an AMR susceptibility test showed that 86% of the isolates were resistant to penicillin, followed by ciprofloxacin (80%) and cefoxitin (52%). Antimicrobial resistance and virulence genes showed that 16% of the isolates carried the mecA gene, while 52% of the isolates carried the Lg G-binding region gene, followed by coa (42%), spa (40%), hla (38%), and hlb (38%), whereas sea and bap genes were detected in 10% and 2% of the isolates, respectively. The occurrence of virulence factors and antimicrobial resistance profiles highlights the need for appropriate strategies to control the spread of these pathogens. | 2024 | 38200885 |
| 2709 | 5 | 0.9998 | Isolation, genotyping and antibiotic resistance analysis in Salmonella species isolated from turkey meat in Isfahan, Iran. Salmonella is one of the mainzoonotic bacteria in the poultry industry.The knowledge about biological characteristics and antibiotic resistance pattern can help medication in poultry and human. This research aimed to study Salmonella spp contamination and its antibiotic resistance in turkey meat in Isfahan province, Iran.400 samples were collected from the turkey meat in slaughter line (May 2021 to May 2022). The conventional microbiological and biochemical tests were applied for isolation and typing of Salmonella spp. The polymerase chain reaction (PCR) was utilized for detection and typing of Salmonella strains. The antibiotic sensitivity test was achieved and all strains were evaluated for resistance genes of Act (3)-IV, Sul1 and qnrA. In microbiological examination, 32 Salmonella strains (8 %) were identified. All tested strains were positive for invA gene. By amplifying the FlicC and Prot6E genes, 28 and 4 strains had genes related to enteritidis and typhimurium, respectively. In disc diffusion test, the highest antibiotic resistance was to oxytetracycline (50 %) and the lowest was to gentamicin, amoxiclavulanic acid, cefotaxime and ceftriaxone. The results showed that 6 (18.75 %) and 10 (31.25 %) of the Salmonella spp were able to amplify Sul1 and qnrA genes, respectively. No Salmonella strain could amplify Act (3)-IV gene. 100 % of the strains carried the Sul1 and qnrA genes were resistant to sulfonamide, and enrofloxacin. Furthermore, 3 sulfonamide resistant strains (75 %) and 5 enrofloxacin resistant strains (83.33 %) were harbored Sul1 and qnrA genes, respectively. The prevalence and antibiotic resistance of Salmonella spp in turkey meat can induce health risk concern. However, the wide spectrum antibiotic resistance complicates the proper treatment of Salmonella infection in human. | 2025 | 39944349 |
| 2358 | 6 | 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 |
| 2397 | 7 | 0.9998 | 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 |
| 2391 | 8 | 0.9998 | Antimicrobial resistance and presence of virulence factor genes in Arcanobacterium pyogenes isolated from the uterus of postpartum dairy cows. Arcanobacterium pyogenes is considered the most significant bacterium involved in the pathogenesis of metritis in cattle. Infections caused by antimicrobial-resistant bacteria are a great challenge in both human and veterinary medicine. The purpose of this study was to present an overview of antimicrobial resistance in A. pyogenes isolated from the uteruses of postpartum Holstein dairy cows and to identify virulence factors. Seventy-two A. pyogenes isolates were phenotypically characterized for antimicrobial resistance to amoxicillin, ampicillin, ceftiofur, chloramphenicol, florfenicol, oxytetracycline, penicillin, spectinomycin, streptomycin and tetracycline by the broth microdilution method. Presence of virulence factor genes of A. pyogenes was investigated. Isolates exhibited resistance to all antimicrobial agents tested; high levels of resistance were found to amoxicillin (56.9%); ampicillin (86.1%), chloramphenicol (100%), florfenicol (59.7%), oxytetracycline (54.2%), penicillin (86.1%) and tetracycline (50%). Of all isolates, 69 (95.8%) were resistant to at least 2 of the antimicrobial agents tested and multidrug resistance (resistant to at least 3 antimicrobials) was observed in 64 (88.9%) of the A. pyogenes isolates. The major multidrug resistance profile was found for chloramphenicol-ampicillin-penicillin-florfenicol-amoxicillin-tetracycline, which was observed in 21 (29.2%) multidrug resistant isolates. No isolate was resistant to all nine antimicrobial agents tested but four isolates (5.6%) were resistant to eight antimicrobials. The information highlights the need for prudent use of specific antimicrobial agents. All four virulence factor genes occurred in isolates from normal puerperium and clinical metritis; however, the fimA gene was present in significantly higher frequency in isolates from metritis cows. | 2010 | 20346602 |
| 2707 | 9 | 0.9998 | Emergence of colistin resistance and characterization of antimicrobial resistance and virulence factors of Aeromonas hydrophila, Salmonella spp., and Vibrio cholerae isolated from hybrid red tilapia cage culture. BACKGROUND: Tilapia is a primary aquaculture fish in Thailand, but little is known about the occurrence of antimicrobial resistance (AMR) in Aeromonas hydrophila, Salmonella spp., and Vibrio cholerae colonizing healthy tilapia intended for human consumption and the co-occurrence of these AMR bacteria in the cultivation water. METHODS: This study determined the phenotype and genotype of AMR, extended-spectrum β-lactamase (ESBL) production, and virulence factors of A. hydrophila, Salmonella spp., and V. cholerae isolated from hybrid red tilapia and cultivation water in Thailand. Standard culture methods such as USFDA's BAM or ISO procedures were used for the original isolation, with all isolates confirmed by biochemical tests, serotyping, and species-specific gene detection based on PCR. RESULTS: A total of 278 isolates consisting of 15 A. hydrophila, 188 Salmonella spp., and 75 V. cholerae isolates were retrieved from a previous study. All isolates of A. hydrophila and Salmonella isolates were resistance to at least one antimicrobial, with 26.7% and 72.3% of the isolates being multidrug resistant (MDR), respectively. All A. hydrophila isolates were resistant to ampicillin (100%), followed by oxytetracycline (26.7%), tetracycline (26.7%), trimethoprim (26.7%), and oxolinic acid (20.0%). The predominant resistance genes in A. hydrophila were mcr-3 (20.0%), followed by 13.3% of isolates having floR, qnrS, sul1, sul2, and dfrA1. Salmonella isolates also exhibited a high prevalence of resistance to ampicillin (79.3%), oxolinic acid (75.5%), oxytetracycline (71.8%), chloramphenicol (62.8%), and florfenicol (55.3%). The most common resistance genes in these Salmonella isolates were qnrS (65.4%), tetA (64.9%), bla (TEM) (63.8%), and floR (55.9%). All V. cholerae isolates were susceptible to all antimicrobials tested, while the most common resistance gene was sul1 (12.0%). One isolate of A. hydrophila was positive for int1, while all isolates of Salmonella and V. cholerae isolates were negative for integrons and int (SXT). None of the bacterial isolates in this study were producing ESBL. The occurrence of mcr-3 (20.0%) in these isolates from tilapia aquaculture may signify a serious occupational and consumer health risk given that colistin is a last resort antimicrobial for treatment of Gram-negative bacteria infections. CONCLUSIONS: Findings from this study on AMR bacteria in hybrid red tilapia suggest that aquaculture as practiced in Thailand can select for ubiquitous AMR pathogens, mobile genetic elements, and an emerging reservoir of mcr and colistin-resistant bacteria. Resistant and pathogenic bacteria, such as resistance to ampicillin and tetracycline, or MDR Salmonella circulating in aquaculture, together highlight the public health concerns and foodborne risks of zoonotic pathogens in humans from cultured freshwater fish. | 2023 | 36855429 |
| 2671 | 10 | 0.9998 | Toxinotyping and molecular characterization of antimicrobial resistance in Clostridium perfringens isolated from different sources of livestock and poultry. The present study was designed to understand the presence of antimicrobial resistance among the prevalent toxinotypes of Clostridium perfringens recovered from different animals of Tamil Nadu, India. A total of 75 (10.76%) C. perfringens were isolated from 697 multi-species fecal and intestinal content samples. C. perfringens type A (90.67%), type C (2.67%), type D (4%) and type F (2.67%) were recovered. Maximum number of isolates were recovered from dog (n = 20, 24.10%) followed by chicken (n = 19, 5.88%). Recovered isolates were resistant to gentamicin (44.00%), erythromycin (40.00%), bacitracin (40.00%), and tetracycline (26.67%), phenotypically and most of the isolates were found to be resistant to multiple antimicrobials. Genotypic characterization revealed that tetracycline (41.33%), erythromycin (34.66%) and bacitracin (17.33%) resistant genes were present individually or in combination among the isolates. Combined results of phenotypic and genotypic characterization showed the highest percentage of erythromycin resistance (26.66%) among the isolates. None of the isolates showed amplification for lincomycin resistance genes. The correlation matrix analysis of genotypic resistance showed a weak positive relationship between the tetracycline and bacitracin resistance while a weak negative relationship between the tetracycline and erythromycin resistance. The present study thus reports the presence of multiple-resistance genes among C. perfringens isolates that may be involved in the dissemination of resistance to other bacteria present across species. Further insights into the genome can help to understand the mechanism involved in gene transfer so that measures can be taken to prevent the AMR spread. | 2021 | 33220406 |
| 1286 | 11 | 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 |
| 2700 | 12 | 0.9998 | Prevalence of Salmonella Typhimurium and Salmonella Enteritidis isolated from poultry meat: virulence and antimicrobial-resistant genes. Salmonellosis, a zoonotic disease, is one of the leading causes of foodborne illness worldwide. It is responsible for most infections caused by consumption of contaminated food. In recent years, a significant increase in the resistance of these bacteria to common antibiotics has been observed, posing a serious threat to global public health. The aim of this study was to investigate the prevalence of virulent antibiotic-resistant Salmonella spp. strains in Iranian poultry markets. A total of 440 chicken meat samples were randomly selected from meat supply and distribution facilities in Shahrekord and tested for bacteriological contamination. After culturing and isolating the strains, identification was performed using the classical bacteriological method and PCR. To determine antibiotic resistance, a disc diffusion test was performed according to the recommendations of the French Society of Microbiology. PCR was used to detect resistance and virulence genes. Only 9% of the samples were positive for Salmonella. These were Salmonella typhimurium isolates. All Salmonella typhimurium serotypes tested positive for the rfbJ, fljB, invA and fliC genes. Resistance to TET, cotrimoxazole, NA, NIT, piperacillin/tazobactam and other antibiotics was found in 26 (72.2%), 24 (66.7%), 22 (61.1%) and 21 (58.3%) isolates, respectively. The sul1, sul2 and sul3 genes were present in 20, 12 and 4 of 24 cotrimoxazole-resistant bacteria, respectively. Chloramphenicol resistance was found in six isolates, but more isolates tested positive for the floR and cat two genes. In contrast, 2 (33%) of the cat three genes, 3 (50%) of the cmlA genes and 2 (34%) of the cmlB genes were all positive. The results of this investigation showed that Salmonella typhimurium is the most common serotype of the bacterium. This means that most of the antibiotics commonly used in the livestock and poultry industries are ineffective against most Salmonella isolates, which is important for public health. | 2023 | 37322421 |
| 2398 | 13 | 0.9998 | 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 |
| 2672 | 14 | 0.9998 | Antimicrobial-Resistance and Virulence-Associated Genes of Pasteurella multocida and Mannheimia haemolytica Isolated from Polish Dairy Calves with Symptoms of Bovine Respiratory Disease. Bovine respiratory disease causes significant economic losses in cattle farming due to mortality, treatment costs, and reduced productivity. It involves viral and bacterial infections, with Pasteurella multocida and Mannheimia haemolytica key bacterial pathogens. These bacteria contribute to severe pneumonia and are often found together. Poland has one of the highest levels of antimicrobial use in food-producing animals among European Union countries. A total of 70 bacterial strains were analyzed, 48 P. multocida and 22 M. haemolytica, collected from affected calves' respiratory tracts. The bacterial species were confirmed molecularly using PCR, which was also employed to detect antimicrobial resistance and virulence-associated genes. Antimicrobial susceptibility was determined using the broth microdilution method. Antimicrobial resistance varied between the two bacterial species studied. The highest resistance in P. multocida was to chlortetracycline 79.2% (38/48) and oxytetracycline 81.3% (39/48), while M. haemolytica showed 63.6% (14/22) resistance to penicillin and tilmicosin. The highest susceptibility was found for fluoroquinolones: P. multocida demonstrated 91.7% (44/48) susceptibility to enrofloxacin and 87.5% (42/48) to danofloxacin, while 77.3% (17/22) of M. haemolytica were susceptible to both tested fluoroquinolones. The tetH and tetR genes were observed only in P. multocida, at frequencies of 20.8% (10/48) and 16.7% (8/48), respectively. Both species carried the mphE and msrE genes, though at lower frequencies. All M. haemolytica contained the lkt, gs60, and gcp genes. All P. multocida carried the sodA gene, while the hgbB and ompH genes were present in 37.5% (18/48) and 20.8% (10/48) of strains, respectively. The highest resistance was observed against the most commonly used antibiotics in the European Union, although the resistance differed between the studied bacterial species and each strain exhibited the presence of at least one virulence gene. | 2025 | 40142384 |
| 2701 | 15 | 0.9998 | Detection of antibiotic-resistant bacteria and their resistance genes from houseflies. BACKGROUND AND AIM: Houseflies (Musca domestica) are synanthropic insects which serve as biological or mechanical vectors for spreading multidrug-resistant bacteria responsible for many infectious diseases. This study aimed to detect antibiotic-resistant bacteria from houseflies, and to examine their resistance genes. MATERIALS AND METHODS: A total of 140 houseflies were captured using sterile nylon net from seven places of Mymensingh city, Bangladesh. Immediately after collection, flies were transferred to a sterile zipper bag and brought to microbiology laboratory within 1 h. Three bacterial species were isolated from houseflies, based on cultural and molecular tests. After that, the isolates were subjected to antimicrobial susceptibility testing against commonly used antibiotics, by the disk diffusion method. Finally, the detection of antibiotic resistance genes tetA, tetB, mcr-3, mecA, and mecC was performed by a polymerase chain reaction. RESULTS: The most common isolates were Staphylococcus aureus (78.6%), Salmonella spp., (66.4%), and Escherichia coli (51.4%). These species of bacteria were recovered from 78.3% of isolates from the Mymensingh Medical College Hospital areas. Most of the isolates of the three bacterial species were resistant to erythromycin, tetracycline, penicillin and amoxicillin and were sensitive to ciprofloxacin, ceftriaxone, chloramphenicol, gentamicin, and azithromycin. Five antibiotic resistance genes of three bacteria were detected: tetA, tetB, mcr-3, and mecA were found in 37%, 20%, 20%, and 14% isolates, respectively, and no isolates were positive for mecC gene. CONCLUSION: S. aureus, Salmonella spp., and E. coli with genetically-mediated multiple antibiotic resistance are carried in houseflies in the Mymensingh region. Flies may, therefore, represent an important means of transmission of these antibiotic-resistant bacteria, with consequent risks to human and animal health. | 2020 | 32255968 |
| 2670 | 16 | 0.9998 | 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 |
| 2719 | 17 | 0.9998 | Antimicrobial resistance and virulence signatures of Listeria and Aeromonas species recovered from treated wastewater effluent and receiving surface water in Durban, South Africa. BACKGROUND: Treated wastewater effluent has been found to contain high levels of contaminants, including disease-causing bacteria such as Listeria and Aeromonas species. The aim of this study was to evaluate the antimicrobial resistance and virulence signatures of Listeria and Aeromonas spp. recovered from treated effluents of two wastewater treatment plants and receiving rivers in Durban, South Africa. METHODS: A total of 100 Aeromonas spp. and 78 Listeria spp. were positively identified based on biochemical tests and PCR detection of DNA region conserved in these genera. The antimicrobial resistance profiles of the isolates were determined using Kirby Bauer disc diffusion assay. The presence of important virulence genes were detected via PCR, while other virulence determinants; protease, gelatinase and haemolysin were detected using standard assays. RESULTS: Highest resistance was observed against penicillin, erythromycin and nalidixic acid, with all 78 (100%) tested Listeria spp displaying resistance, followed by ampicillin (83.33%), trimethoprim (67.95%), nitrofurantoin (64.10%) and cephalosporin (60.26%). Among Aeromonas spp., the highest resistance (100%) was observed against ampicillin, penicillin, vancomycin, clindamycin and fusidic acid, followed by cephalosporin (82%), and erythromycin (58%), with 56% of the isolates found to be resistant to naladixic acid and trimethoprim. Among Listeria spp., 26.92% were found to contain virulence genes, with 14.10, 5.12 and 21% harbouring the actA, plcA and iap genes, respectively. Of the 100 tested Aeromonas spp., 52% harboured the aerolysin (aer) virulence associated gene, while lipase (lip) virulence associated gene was also detected in 68% of the tested Aeromonas spp. CONCLUSIONS: The presence of these organisms in effluents samples following conventional wastewater treatment is worrisome as this could lead to major environmental and human health problems. This emphasizes the need for constant evaluation of the wastewater treatment effluents to ensure compliance to set guidelines. | 2015 | 26498595 |
| 2967 | 18 | 0.9998 | Antibiotic susceptibility and prevalence of foodborne pathogens in poultry meat in Romania. INTRODUCTION: The occurrence of pathogenic strains in poultry meat is of growing concern in Romania. Another problem found on a global level is the continuous increase of antimicrobial resistance in bacteria isolated from food. This study aimed to evaluate the prevalence of pathogenic bacteria in poultry carcasses obtained in Romania in 2012-2013 and to reveal the most prevalent patterns of antimicrobial resistance in the isolated strains. METHODOLOGY: A total of 144 broiler chicken carcasses were evaluated according to classical microbiological methods. The DNA was extracted from the bacterial colonies and the resistance genes were identified by PCR. RESULTS: In 2012, 47.2% of the samples revealed at least one of the following bacteria: Campylobacter jejuni (9.72%; n = 7), Salmonella enterica serotype Enteritidis (4.17%; n = 3), Listeria monocytogenes (15.28%; n = 11), and Escherichia coli (16.67%; n = 12). In 2013, the number of positive samples of pathogenic bacteria decreased, although Campylobacter jejuni was isolated in a higher percentage (20.8% vs. 9.72%). The percentage of multidrug-resistant (MDR) bacteria was high (23%); the most prevalent pattern included resistance to tetracycline, sulfonamides, and quinolones/fluoroquinolones. All the resistant Salmonella and E. coli strains were tested for the presence of characteristic resistance genes (Kn, bla(TEM), tetA, tetB, tetG, DfrIa, aadA1a, Sul) and revealed that these isolates represent an important reservoir in the spread of this phenomenon. CONCLUSIONS: Our findings suggest that Romania urgently needs an integrated surveillance system within the entire chain, for drug-resistant pathogens isolated from poultry meat. | 2015 | 25596569 |
| 2693 | 19 | 0.9998 | Prevalence, Antimicrobial Resistance and Toxin-Encoding Genes of Clostridioides difficile from Environmental Sources Contaminated by Feces. Clostridioides difficile (C. difficile) is the most common pathogen causing antibiotic-associated intestinal diseases in humans and some animal species, but it can also be present in various environments outside hospitals. Thus, the objective of this study was to investigate the presence and the characteristics of toxin-encoding genes and antimicrobial resistance of C. difficile isolates from different environmental sources. C. difficile was found in 32 out of 81 samples (39.50%) after selective enrichment of spore-forming bacteria and in 45 samples (55.56%) using a TaqMan-based qPCR assay. A total of 169 C. difficile isolates were recovered from those 32 C. difficile-positive environmental samples. The majority of environmental C. difficile isolates were toxigenic, with many (88.75%) positive for tcdA and tcdB. Seventy-four isolates (43.78%) were positive for binary toxins, cdtA and cdtB, and 19 isolates were non-toxigenic. All the environmental C. difficile isolates were susceptible to vancomycin and metronidazole, and most isolates were resistant to ciprofloxacin (66.86%) and clindamycin (46.15%), followed by moxifloxacin (13.02%) and tetracycline (4.73%). Seventy-five isolates (44.38%) showed resistance to at least two of the tested antimicrobials. C. difficile strains are commonly present in various environmental sources contaminated by feces and could be a potential source of community-associated C. difficile infections. | 2023 | 36671363 |