# | Rank | Similarity | Title + Abs. | Year | PMID |
|---|---|---|---|---|---|
| 0 | 1 | 2 | 3 | 4 | 5 |
| 1903 | 0 | 0.8346 | Can a regulatory control network be used for a territorial monitoring of antimicrobial resistance in water intended for human consumption? Antimicrobial resistance genes and resistant bacteria could be found in water intended for human consumption (WIHC). In France, although the microbiological quality of WIHC is strictly monitored, antimicrobial resistance is not. The aim of this study is to test the concept of the use of the regulatory surveillance of WIHC to monitor antimicrobial resistance in a French area. Based on 2211 Petri dishes seeded for regulatory enumeration of Escherichia coli, that corresponds to sanitary surveillance of 2 French departments from January to April 2021, we characterized phenotypic and genotypic resistance of isolated E. coli strains. bla(TEM), bla(SHV), bla(CTX-M) that are the most frequent beta-lactamases-encoding genes in human infections were also researched on cultivable Gram negative-community. | 2024 | 39396793 |
| 2452 | 1 | 0.8308 | Worrying levels of antimicrobial resistance in Gram-negative bacteria isolated from cell phones and uniforms of Peruvian intensive care unit workers. BACKGROUND: Healthcare worker (HCW) uniforms and cell phones are involved in pathogen transmission. This study aimed to characterize pathogenic microorganism isolates from HCW uniforms and cell phones. METHODS: Gram-negative microorganisms were recovered from HCW uniforms and cell phones. Antimicrobial susceptibility and the presence of extended-spectrum β-lactamases (ESBL) and carbapenemases were determined. RESULTS: Escherichia coli was the most prevalent microorganism. Overall, high levels of resistance to cephalosporins, quinolones, co-trimoxazole and colistin were found. ESBL were mainly related to blaCTX-M-15 and blaSHV- genes. Carbapenem-resistant isolates presented as blaKPC or blaNDM. CONCLUSIONS: High levels of antimicrobial resistance, including colistin, were detected. Therefore, strategies are urgently needed to prevent bacterial dissemination. | 2022 | 34993550 |
| 1401 | 2 | 0.8292 | Molecular Surveillance of Multidrug-Resistant Bacteria among Refugees from Afghanistan in 2 US Military Hospitals during Operation Allies Refuge, 2021. In 2021, two US military hospitals, Landstuhl Regional Medical Center in Landstuhl, Germany, and Walter Reed National Military Medical Center (WRNMMC) in Bethesda, Maryland, USA, observed a high prevalence of multidrug-resistant bacteria among refugees evacuated from Afghanistan during Operation Allies Refuge. Multidrug-resistant isolates collected from 80 patients carried an array of antimicrobial resistance genes, including carbapenemases (bla(NDM-1), bla(NDM-5), and bla(OXA-23)) and 16S methyltransferases (rmtC and rmtF). Considering the rising transmission of antimicrobial resistance and unprecedented population displacement globally, these data are a reminder of the need for robust infection control measures and surveillance. | 2024 | 39530854 |
| 101 | 3 | 0.8290 | The encapsulated strain TIGR4 of Streptococcus pneumoniae is phagocytosed but is resistant to intracellular killing by mouse microglia. The polysaccharide capsule is a major virulence factor of Streptococcus pneumoniae as it confers resistance to phagocytosis. The encapsulated serotype 4 TIGR4 strain was shown to be efficiently phagocytosed by the mouse microglial cell line BV2, whereas the type 3 HB565 strain resisted phagocytosis. Comparing survival after uptake of TIGR4 or its unencapsulated derivative FP23 in gentamicin protection and phagolysosome maturation assays, it was shown that TIGR4 was protected from intracellular killing. Pneumococcal capsular genes were up-regulated in intracellular TIGR4 bacteria recovered from microglial cells. Actual presence of bacteria inside BV2 cells was confirmed by transmission electron microscopy (TEM) for both TIGR4 and FP23 strains, but typical phagosomes/phagolysosomes were detected only in cells infected with the unencapsulated strain. In a mouse model of meningitis based on intracranic inoculation of pneumococci, TIGR4 caused lethal meningitis with an LD(50) of 2 × 10² CFU, whereas the LD(50) for the unencapsulated FP23 was greater than 10⁷ CFU. Phagocytosis of TIGR4 by microglia was also demonstrated by TEM and immunohistochemistry on brain samples from infected mice. The results indicate that encapsulation does not protect the TIGR4 strain from phagocytosis by microglia, while it affords resistance to intracellular killing. | 2010 | 20615478 |
| 6130 | 4 | 0.8284 | Characterization of the virulence, growth temperature and antibiotic resistance of the Campylobacter jejuni IAL 2383 strain isolated from humans. The objective of this study was to characterize the C. jejuni IAL2383 strain isolated from humans in Brazil. Transcripts for the racR, dnaJ and ciaB genes were found and flaA, plda and cadF genes were present in the genome and bacteria was sensitive to most of the important antimicrobials used to treat humans. C. jejuni IAL2383 is a good experimental model to analyze the interactions with cells. | 2014 | 24948944 |
| 5240 | 5 | 0.8276 | Dynamics of Antimicrobial Resistance Carriage in Koalas (Phascolarctos Cinereus) and Pteropid Bats (Pteropus Poliocephalus) Before, During and After Wildfires. In the 2019-2020 summer, wildfires decimated the Australian bush environment and impacted wildlife species, including koalas (Phascolarctos cinereus) and grey headed flying fox pups (Pteropid bats, Pteropus poliocephalus). Consequently, hundreds of koalas and thousands of bat pups entered wildlife hospitals with fire-related injuries/illness, where some individuals received antimicrobial therapy. This study investigated the dynamics of antimicrobial resistance (AMR) in pre-fire, fire-affected and post-fire koalas and Pteropid bat pups. PCR and DNA sequencing were used to screen DNA samples extracted from faeces (koalas and bats) and cloacal swabs (koalas) for class 1 integrons, a genetic determinant of AMR, and to identify integron-associated antibiotic resistance genes. Class 1 integrons were detected in 25.5% of koalas (68 of 267) and 59.4% of bats (92 of 155). Integrons contained genes conferring resistance to aminoglycosides, trimethoprim and beta-lactams. Samples were also screened for blaTEM (beta-lactam) resistance genes, which were detected in 2.6% of koalas (7 of 267) and 25.2% of bats (39 of 155). Integron occurrence was significantly higher in fire-affected koalas in-care compared to wild pre-fire koalas (P < 0.0001). Integron and blaTEM occurrence were not significantly different in fire-affected bats compared to pre-fire bats (P > 0.05), however, their occurrence was significantly higher in fire-affected bats in-care compared to wild fire-affected bats (P < 0.0001 and P = 0.0488 respectively). The observed shifts of AMR dynamics in wildfire-impacted species flags the need for judicious antibiotic use when treating fire-affected wildlife to minimise unwanted selective pressure and negative treatment outcomes associated with carriage of resistance genes and antibiotic resistant bacteria. | 2024 | 38332161 |
| 814 | 6 | 0.8273 | Drown Them in Their Own Garbage: a New Strategy To Reverse Polymyxin Resistance? Purcell and colleagues offer new insights into a major mechanism of polymyxin resistance in Gram-negative bacteria (A. B. Purcell, B. J. Voss, and M. S. Trent, J Bacteriol 204:e00498-21, 2022, https://doi.org/10.1128/JB.00498-21). Inactivating a single lipid recycling enzyme causes accumulation of waste lipid by-products that inhibit a key factor responsible for polymyxin resistance. | 2022 | 34843378 |
| 1474 | 7 | 0.8273 | Simple, rapid, and cost-effective modified Carba NP test for carbapenemase detection among Gram-negative bacteria. PURPOSE: Detection of carbapenemases among Gram-negative bacteria (GNB) is important for both clinicians and infection control practitioners. The Clinical and Laboratory Standards Institute recommends Carba NP (CNP) as confirmatory test for carbapenemase production. The reagents required for CNP test are costly and hence the test cannot be performed on a routine basis. The present study evaluates modifications of CNP test for rapid detection of carbapenemases among GNB. MATERIALS AND METHODS: The GNB were screened for carbapenemase production using CNP, CarbAcineto NP (CANP), and modified CNP (mCNP) test. A multiplex polymerase chain reaction (PCR) was performed on all the carbapenem-resistant bacteria for carbapenemase genes. The results of three phenotypic tests were compared with PCR. RESULTS: A total of 765 gram negative bacteria were screened for carbapenem resistance. Carbapenem resistance was found in 144 GNB. The metallo-β-lactamases were most common carbapenemases followed by OXA-48-like enzymes. The CANP test was most sensitive (80.6%) for carbapenemases detection. The mCNP test was 62.1% sensitive for detection of carbapenemases. The mCNP, CNP, and CANP tests were equally sensitive (95%) for detection of NDM enzymes among Enterobacteriaceae. The mCNP test had poor sensitivity for detection of OXA-48-like enzymes. CONCLUSION: The mCNP test was rapid, cost-effective, and easily adoptable on routine basis. The early detection of carbapenemases using mCNP test will help in preventing the spread of multidrug-resistant organisms in the hospital settings. | 2017 | 28966495 |
| 1382 | 8 | 0.8270 | Surveillance of antimicrobial-resistant Escherichia coli in Sheltered dogs in the Kanto Region of Japan. There is a lack of an established antimicrobial resistance (AMR) surveillance system in animal welfare centers. Therefore, the AMR prevalence in shelter dogs is rarely known. Herein, we conducted a survey in animal shelters in Chiba and Kanagawa prefectures, in the Kanto Region, Japan, to ascertain the AMR status of Escherichia coli (E. coli) prevalent in shelter dogs. E. coli was detected in the fecal samples of all 61 and 77 shelter dogs tested in Chiba and Kanagawa, respectively. The AMR was tested against 20 antibiotics. E. coli isolates derived from 16.4% and 26.0% of samples from Chiba and Kanagawa exhibited resistance to at least one antibiotic, respectively. E. coli in samples from Chiba and Kanagawa prefectures were commonly resistant to ampicillin, piperacillin, streptomycin, kanamycin, tetracycline, and nalidixic acid; that from the Kanagawa Prefecture to cefazolin, cefotaxime, aztreonam, ciprofloxacin, and levofloxacin and that from Chiba Prefecture to chloramphenicol and imipenem. Multidrug-resistant bacteria were detected in 18 dogs from both regions; β-lactamase genes (blaTEM, blaDHA-1, blaCTX-M-9 group CTX-M-14), quinolone-resistance protein genes (qnrB and qnrS), and mutations in quinolone-resistance-determining regions (gyrA and parC) were detected. These results could partially represent the AMR data in shelter dogs in the Kanto Region of Japan. | 2022 | 35031646 |
| 1483 | 9 | 0.8264 | Clinical Evaluation of the iCubate iC-GPC Assay for Detection of Gram-Positive Bacteria and Resistance Markers from Positive Blood Cultures. The iC-GPC Assay (iCubate, Huntsville, AL) is a qualitative multiplex test for the detection of five of the most common Gram-positive bacteria (Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus pneumoniae, Enterococcus faecalis, and Enterococcus faecium) responsible for bacterial bloodstream infections, performed directly from positive blood cultures. The assay also detects the presence of the mecA, vanA, and vanB resistance determinants. This study comparatively evaluated the performance of the iC-GPC Assay against the Verigene Gram-positive blood culture (BC-GP) assay (Luminex Corp., Austin, TX) for 1,134 patient blood culture specimens positive for Gram-positive cocci. The iC-GPC Assay had an overall percent agreement with the BC-GP assay of 95.5%. Discordant specimens were further analyzed by PCR and a bidirectional sequencing method. The results indicate that the iC-GPC Assay together with the iCubate system is an accurate and reliable tool for the detection of the five most common Gram-positive bacteria and their resistance markers responsible for bloodstream infections. | 2018 | 29899000 |
| 1393 | 10 | 0.8263 | Prevalence, antimicrobial resistance and detection of virulence genes of Escherichia coli and Salmonella spp. isolated from white-lipped peccaries and collared peccaries. Salmonella spp. and Escherichia coli are implicated in human and animal infections and require antimicrobial treatment in many situations. Faecal samples of healthy white-lipped peccaries (Pecari tajacu) (n = 30) and collared peccaries (Tayassu pecari ) (n = 60) obtained in three farms located in the Midwest Brazil. The antimicrobial profiles of commensal E. coli from P. tajacu and T. pecari from commercial herds in Brazil were isolated and analyzed and virulence genes were detected. Among 90 healthy animals, no Salmonella spp. were isolated. However, 30 samples (27%) tested positive for E. coli, with 18 isolates from P. tajacu and 12 from T. pecari, representing frequencies of 58.0% and 38.7%, respectively. Additionally, other Enterobacteriaceae family bacteria were detected but not included in this analysis. However, individual samples from 30 animals tested positive for E. coli, of which 16 were isolated from P. tajacu presenting multidrug resistance and six were isolated from T. pecari presenting a similar pattern. The E. coli virulence genes detected were papC (pilus-associated pyelonephritis) in five isolates, tsh (temperature-sensitive hemagglutinin) in one isolate, and eae (enteric attachment and effacement) in one isolate. The serum resistance gene, iss (increased serum survival), was detected in four isolates. An association between these genes and the presence of hemolysin was also observed in one isolate. Thus, T. pecari and P. tajacu are potential reservoirs of pathogenic and multidrug-resistant and E. coli. Faecal E. coli of healthy P. tajacu and T. pecari could act as a possible reservoir of antimicrobial resistance genes in environment. | 2024 | 38713279 |
| 3740 | 11 | 0.8257 | Stp1 Loss of Function Promotes β-Lactam Resistance in Staphylococcus aureus That Is Independent of Classical Genes. β-Lactam resistance in Staphylococcus aureus limits treatment options. Stp1 and Stk1, a serine-threonine phosphatase and kinase, respectively, mediate serine-threonine kinase (STK) signaling. Loss-of-function point mutations in stp1 were detected among laboratory-passaged β-lactam-resistant S. aureus strains lacking mecA and blaZ, the major determinants of β-lactam resistance in the bacteria. Loss of Stp1 function facilitates β-lactam resistance of the bacteria. | 2020 | 32179529 |
| 1741 | 12 | 0.8255 | Detection of SGI1/PGI1 Elements and Resistance to Extended-Spectrum Cephalosporins in Proteae of Animal Origin in France. Proteae, and especially Proteus mirabilis, are often the cause of urinary tract infections (UTIs) in humans. They were reported as carriers of extended-spectrum β-lactamase (ESBL) genes, and recently of carbapenemases, mostly carried by the Salmonella genomic island 1 (SGI1) and Proteus genomic island 1 (PGI1). Proteae have also lately become an increasing cause of UTIs in companion animals, but antimicrobial susceptibility data in animals are still scarce. Here, we report the characterization of 468 clinical epidemiologically unrelated Proteae strains from animals collected between 2013 and 2015 in France. Seventeen P. mirabilis strains (3.6%) were positive for SGI1/PGI1 and 18 Proteae (3.8%) were resistant to extended-spectrum cephalosporins (ESC). The 28 isolates carrying SGI1/PGI1 and/or ESC-resistance genes were isolated from cats, dogs, and horses. ESBL genes were detected in six genetically related P. mirabilis harboring bla(V EB-6) on the SGI1-V variant, but also independently of the SGI1-V, in 3 P. mirabilis strains (bla(VEB-6) and bla(CTX-M-15)) and 1 Providencia rettgeri strain (bla(CTX-M-1)). The AmpC resistance genes bla(CMY -2) and/or bla(DHA-16) were detected in 9 P. mirabilis strains. One strain presented both an ESBL and AmpC gene. Interestingly, the majority of the ESBL/AmpC resistance genes were located on the chromosome. In conclusion, multiple ESC-resistance genetic determinants are circulating in French animals, even though SGI1-V-carrying P. mirabilis seems to be mainly responsible for the spread of the ESBL gene bla(VEB-6) in dogs and horses. These results are of public health relevance and show that companion animals in close contact with humans should be regarded as a potential reservoir of ESC-resistant bacteria as well as a reservoir of ESC-resistance genes that could further disseminate to human pathogens. | 2017 | 28154560 |
| 1384 | 13 | 0.8255 | Antimicrobial resistance in wildlife: detection of antimicrobial resistance genes in Apennine wolves (Canis lupus italicus Altobello, 1921) from Central Italy. The aim of this study was to molecularly investigate the presence of antimicrobial resistance genes (ARGs) in organ samples from 11 Apennine wolves (Canis lupus italicus) collected in Central Italy. Samples from lung, liver, spleen, kidney, tongue and intestine were investigated by PCRs targeting the following genes: tet(A), tet(B), tet(C), tet(D), tet(E), tet(G), tet(K), tet(L), tet(M), tet(O), tetA(P), tet(Q), tet(S), tet(X), sul1, sul2, sul3, bla(CTX-M), bla(SHV), bla(TEM) and mcr-1. A PCR positivity was highlighted for 13 out of the 21 tested genes; no positive results were obtained for tet(C), tet(D), tet(E), tet(G), sul3, bla(CTX), bla(SHV) and mcr-1 genes. All 11 animals sampled showed positivity for one or more resistance genes. The results confirm the potential role of the wolf as an indicator and/or vector of antimicrobial-resistant bacteria or ARGs. | 2024 | 38499909 |
| 1391 | 14 | 0.8255 | Faecal carriage of extended-spectrum β-lactamase-producing and AmpC β-lactamase-producing bacteria among Danish army recruits. During May and June 2008, 84 Danish army recruits were tested for faecal carriage of extended-spectrum β-lactamase (ESBL)-producing and AmpC β-lactamase-producing bacteria. Three ESBL-producing (CTX-M-14a) Escherichia coli isolates, two AmpC-producing (CMY-2) E. coli isolates and one AmpC-producing (CMY-34) Citrobacter freundii isolate were detected. Two of the CTX-M-14a E. coli isolates had similar pulsed-field gel electrophoresis and multilocus sequence typing profiles, indicating the same origin or transmission between the two army recruits. The bla(CTX-M-14a) genes were transferable to an E. coli recipient. These commensal bacteria therefore constitute a reservoir of resistance genes that can be transferred to other pathogenic bacteria in the intestine. | 2011 | 20718802 |
| 5446 | 15 | 0.8255 | Antimicrobial sensitivity trends and virulence genes in Shigella spp. from the Oceania region. Shigella is a common cause of diarrhoea in Papua New Guinea (PNG) and other Oceania countries. However, little is known about the strains causing infection. Archived Shigella isolates (n = 72) were obtained from research laboratories in PNG and reference laboratories in Australia. Shigella virulence genes were detected by PCR, and antimicrobial susceptibility was determined by disk diffusion. The ipaH virulence gene was present in all 72 isolates. The prevalence of other virulence genes was variable, with ial, invE, ipaBCD, sen/ospD3 and virF present in 60% of isolates and set1A and set1B genes present in 42% of isolates. Most S. flexneri isolates contained genes encoding enterotoxin 1 and/or enterotoxin 2. Resistance to antibiotics was common, with 51/72 isolates resistant to 2-4 antimicrobials. A greater proportion of bacteria isolated since 2010 (relative to pre-2010 isolates) were resistant to commonly used antibiotics such as ampicillin, chloramphenicol, tetracycline, and trimethoprim-sulfamethoxazole; suggesting that antimicrobial resistance (AMR) in Shigella is increasing over time in the Oceania region. There is a need for improved knowledge regarding Shigella circulation in the Oceania region and further monitoring of AMR patterns. | 2018 | 29906636 |
| 1386 | 16 | 0.8252 | ESBL/pAmpC-producing Enterobacterales in common leopard geckos (Eublepharis macularius) and central bearded dragons (Pogona vitticeps) from Portugal. Common leopard geckos (Eublepharis macularius) and central bearded dragon (Pogona vitticeps) are widely kept as pets but can harbor pathogenic bacteria, including antimicrobial-resistant (AMR) bacteria. This study aimed to research the frequency of β-lactamase-producing Enterobacterales in these two reptile species. A total of 132 samples were collected from the oral and cloacal cavities of healthy common leopard geckos and central bearded dragons in the Lisbon area, Portugal. Antimicrobial resistance was assessed for third-generation cephalosporin (3GC)-resistant Enterobacterales. The results revealed that 3GC-resistant Enterobacterales were observed in 17.9% (n = 14/78) of the reptiles. The most commonly identified species were: Citrobacter freundii and Klebsiella aerogenes. Furthermore, some isolates produced extended-spectrum β-lactamases (ESBLs) and AmpC β-lactamases (AmpC) encoding genes such as bla (CMY-2), bla (CTX-M-15,) and bla (TEM-1). These findings emphasize the potential role of these reptiles in the spread of AMR bacteria, particularly in urban settings where human- animal interactions are frequent. Given the zoonotic risks, this study emphasizes the importance of continued surveillance and responsible antimicrobial use in both veterinary and human medicine to mitigate the spread of AMR bacteria. | 2025 | 40370835 |
| 2270 | 17 | 0.8252 | Antibiotic resistant bacteria and resistance genes in biofilms in clinical wastewater networks. Increasing isolation rates of resistant bacteria in the last years require identification of potential infection reservoirs in healthcare facilities. Especially the clinical wastewater network represents a potential source of antibiotic resistant bacteria. In this work, the siphons of the sanitary installations from 18 hospital rooms of two German hospitals were examined for antibiotic resistant bacteria and antibiotic residues including siphons of showers and washbasins and toilets in sanitary units of psychosomatic, haemato-oncological, and rehabilitation wards. In addition, in seven rooms of the haemato-oncological ward, the effect of 24 h of stagnation on the antibiotic concentrations and MDR (multi-drug-resistant) bacteria in biofilms was evaluated. Whereas no antibiotic residues were found in the psychosomatic ward, potential selective concentrations of piperacillin, meropenem and ciprofloxacin were detected at a rehabilitation ward and ciprofloxacin and trimethoprim were present at a haemato-oncology ward. Antibiotic resistant bacteria were isolated from the siphons of all wards, however in the psychosomatic ward, only one MDR strain with resistance to piperacillin, third generation cephalosporins and quinolones (3MRGN) was detected. In contrast, the other two wards yielded 11 carbapenemase producing MDR isolates and 15 3MRGN strains. The isolates from the haemato-oncological ward belonged mostly to two specific rare sequence types (ST) (P. aeruginosa ST823 and Enterobacter cloacae complex ST167). In conclusion, clinical wastewater systems represent a reservoir for multi-drug-resistant bacteria. Consequently, preventive and intervention measures should not start at the wastewater treatment in the treatment plant, but already in the immediate surroundings of the patient, in order to minimize the infection potential. | 2019 | 30905579 |
| 1385 | 18 | 0.8252 | GENOMIC CHARACTERIZATION OF MULTIDRUG-RESISTANT EXTENDED-SPECTRUM β-LACTAMASE-PRODUCING ESCHERICHIA COLI AND KLEBSIELLA PNEUMONIAE FROM CHIMPANZEES (PAN TROGLODYTES) FROM WILD AND SANCTUARY LOCATIONS IN UGANDA. Farm and wild animals may serve as reservoirs of antimicrobial-resistant bacteria of human health relevance. We investigated the occurrence and genomic characteristics of extended spectrum β-lactamase (ESBL)-producing bacteria in Ugandan chimpanzees (Pan troglodytes) residing in two environments with or without close contact to humans. The ESBL-producing Escherichia coli and Klebsiella pneumoniae were isolated from fecal material of chimpanzees from Budongo Forest and Ngamba Island Chimpanzee Sanctuary in Uganda and were more commonly isolated from chimpanzees in Ngamba Island Chimpanzee Sanctuary, where animals have close contact with humans. Selected ESBL isolates (E. coli n=9, K. pneumoniae n=7) were analyzed by whole-genome sequencing to determine the presence of resistance genes, as well as sequence type and virulence potential; the blaCTX-M-15 gene was present in all strains. Additionally, the ESBL genes blaSHV-11 and blaSHV-12 were found in strains in the study. All strains were found to be multidrug resistant. The E. coli strains belonged to four sequence types (ST2852, ST215, ST405, and ST315) and the K. pneumoniae strains to two sequence types (ST1540 and ST597). Virulence genes did not indicate that strains were of common E. coli pathotype, but strains with the same sequence types as isolated in the current study have previously been reported from clinical cases in Africa. The findings indicate that chimpanzees in close contact with humans may carry ESBL bacteria at higher frequency than those in the wild, indicating a potential anthropogenic transmission. | 2022 | 35255126 |
| 3056 | 19 | 0.8247 | Spread of a newly found trimethoprim resistance gene, dhfrIX, among porcine isolates and human pathogens. A plasmid-borne gene mediating trimethoprim resistance, dhfrIX, newly found among porcine strains of Escherichia coli, was observed at a frequency of 11% among trimethoprim-resistant veterinary isolates. This rather high frequency of dhfrIX could be due to the extensive use of trimethoprim in veterinary practice in Sweden. After searching several hundred clinical isolates, one human E. coli strain was also found to harbor the dhfrIX gene. Thus, the dhfrIX gene seems to have spread from porcine bacteria to human pathogens. Furthermore, the occurrence of other genes coding for resistant dihydrofolate reductase enzymes (dhfrI, dhfrII, dhfrV, dhfrVII, and dhfrVIII) among the porcine isolates was investigated. In addition, association of dhfr genes with the integraselike open reading frames of transposons Tn7 and Tn21 was studied. In colony hybridization experiments, both dhfrI and dhfrII were found associated with these integrase genes. The most common combination was dhfrI and int-Tn7, indicating a high prevalence of Tn7. | 1992 | 1482138 |