| 1. |
- Alvarez, Laura, et al.
(författare)
-
Peptidoglycan Remodeling by the Coordinated Action of Multispecific Enzymes
- 2014
-
Ingår i: Microbial Drug Resistance. - : Mary Ann Liebert Inc. - 1076-6294 .- 1931-8448. ; 20:3, s. 190-198
-
Tidskriftsartikel (refereegranskat)abstract
- The peptidoglycan (PG) cell wall constitutes the main defense barrier of bacteria against environmental insults and acts as communication interface. The biochemistry of this macromolecule has been well characterized throughout the years but recent discoveries have unveiled its chemical plasticity under environmental stresses. Non-canonical D-amino acids (NCDAA) are produced and released to the extracellular media by diverse bacteria. Such molecules govern cell wall adaptation to challenging environments through their incorporation into the polymer, a widespread capability among bacteria that reveals the inherent catalytic plasticity of the enzymes involved in the cell wall metabolism. Here, we analyze the recent structural and biochemical characterization of Bsr, a new family of broad spectrum racemases able to generate a wide range of NCDAA. We also discuss the necessity of a coordinated action of PG multispecific enzymes to generate adequate levels of modification in the murein sacculus. Finally, we also highlight how this catalytic plasticity of NCDAA-incorporating enzymes has allowed the development of new revolutionary methodologies for the study of PG modes of growth and in vivo dynamics.
|
|
| 2. |
|
|
| 3. |
- Börjesson, Stefan, 1979-, et al.
(författare)
-
Methicillin-resistant Staphylococcus pseudintermedius in Sweden
- 2012
-
Ingår i: Microbial Drug Resistance. - : Mary Ann Liebert. - 1076-6294 .- 1931-8448. ; 18:6, s. 597-603
-
Tidskriftsartikel (refereegranskat)abstract
- Staphylococcus pseudintermedius is an opportunistic pathogen that is one of the most frequent causes of infections in dogs. In Europe, there are increasing reports of methicillin-resistant S. pseudintermedius (MRSP), and in Sweden, MRSP has also been more frequently isolated during recent years. However, there is limited knowledge regarding the epidemiology and genetic relationship among the Swedish isolates. This study therefore investigated the genetic relationship of MRSP isolated from companion animals in Sweden. In the study, MRSP isolates taken in the period January 2008-June 2010 from a total of 226 dogs and cats were characterized by spa typing, pulsed-field gel electrophoresis, and antimicrobial susceptibility testing. In addition, the geographical distribution of the isolates based on year of isolation and genetic typing was determined using a geographical information system. One multiresistant clonal lineage dominated among Swedish MRSP isolates, corresponding to the European winning lineage ST71-J-t02-SCCmec II-III. Furthermore, the geographical dissemination of MRSP corresponded to areas with high dog densities, centered on the three major cities in Sweden where the largest animal hospitals are situated.
|
|
| 4. |
|
|
| 5. |
|
|
| 6. |
|
|
| 7. |
|
|
| 8. |
- Hamasuna, Ryoichi, et al.
(författare)
-
In Vitro Activity of Sitafloxacin and Additional Newer Generation Fluoroquinolones Against Ciprofloxacin-Resistant Neisseria gonorrhoeae Isolates
- 2018
-
Ingår i: Microbial Drug Resistance. - : Mary Ann Liebert. - 1076-6294 .- 1931-8448. ; 24:1, s. 30-34
-
Tidskriftsartikel (refereegranskat)abstract
- Emergence of antimicrobial resistance in Neisseria gonorrhoeae is a major public health concern globally, and new antimicrobials for treatment of gonorrhea are imperative. In this study, the in vitro activity of sitafloxacin, a fluoroquinolone mainly used for respiratory tract or urogenital infections in Japan, and additional newer generation fluoroquinolones were determined against ciprofloxacin-resistant N. gonorrhoeae isolates. Minimum inhibitory concentrations (MICs) of ciprofloxacin, levofloxacin, moxifloxacin, sitafloxacin, pazufloxacin, and tosufloxacin against 47 N. gonorrhoeae isolates cultured in 2009 in Japan were determined by agar dilution method. The quinolone resistance-determining region (QRDR) of gyrA and parC was sequenced. The in vitro potency of sitafloxacin was substantially higher compared with all other tested fluoroquinolones. The MICs of sitafloxacin ranged from 0.03 to 0.5 mg/L for 35 ciprofloxacin-resistant N. gonorrhoeae isolates (ciprofloxacin MICs from 2 to 32 mg/L). No identified mutations in GyrA and ParC QRDR resulted in higher sitafloxacin MIC than 0.5 mg/L. Sitafloxacin had a high activity against N. gonorrhoeae isolates, including strains with mutations in DNA gyrase and topoisomerase IV, resulting in high-level resistance to ciprofloxacin and all other newer generation fluoroquinolones examined. However, it was still to a lower extent affected by GyrA and ParC QRDR mutations resulting in sitafloxacin MICs of up to 0.5 mg/L. This indicates that sitafloxacin should not be considered for empirical first-line monotherapy of gonorrhea. However, sitafloxacin could be valuable in a dual antimicrobial therapy and for cases with ceftriaxone resistance or allergy.
|
|
| 9. |
- Hasan, Badrul, et al.
(författare)
-
Fecal Carriage of Extended-Spectrum -Lactamases in Healthy Humans, Poultry, and Wild Birds in Leon, NicaraguaA Shared Pool of bla(CTX-M) Genes and Possible Interspecies Clonal Spread of Extended-Spectrum -Lactamases-Producing Escherichia coli
- 2016
-
Ingår i: Microbial Drug Resistance. - : Mary Ann Liebert Inc. - 1076-6294 .- 1931-8448. ; 22:8, s. 682-687
-
Tidskriftsartikel (refereegranskat)abstract
- Antibiotic-resistant bacteria are a major concern in the healthcare of today, especially the increasing number of gram-negative bacteria producing -lactamases such as extended-spectrum -lactamases (ESBLs). However, little is known about the relationship of ESBL producers in humans and domestic and wild birds, especially in a low-income setting. Therefore, we studied the fecal carriage of ESBL-producing Escherichia coli and Klebsiella pneumoniae in healthy humans, poultry, and wild birds in the vicinity of Leon, Nicaragua. Three hundred fecal samples were collected during December 2012 from humans (n=100), poultry (n=100) and wild birds (n=100). The samples were examined for ESBL-producing E. coli and K. pneumoniae, revealing the prevalence of 27% in humans, 13% in poultry, and 8% in wild birds. Further characterization of the ESBL-producing isolates was performed through polymerase chain reaction (PCR) (NDM, CTX-M), epidemiological typing (ERIC2-PCR), multilocus sequence typing, and sequencing. ESBL producers harbored bla(CTX-M-2), bla(CTX-M-15), bla(CTX-M-22), and bla(CTX-M-3) genotypes. The bla(CTX-M-15) constituted the absolute majority of ESBL genes among all samples. ERIC-PCR demonstrated highly related E. coli clones among humans, poultry, and wild birds. Clinically relevant E. coli clone ST648 was found in humans and poultry. There is a shared pool of bla(CTX-M) genes between humans and domesticated and wild birds in Nicaragua, and the results suggest shared clones of ESBL-producing E. coli. The study adds to the notion that wild birds and poultry can pick up antibiotic-resistant bacteria of human origin and function as a melting pot of resistance. Structured surveillance programs of antimicrobial resistance and a more regulated prescription of antibiotics are warranted in Nicaragua.
|
|
| 10. |
- Hasan, Badrul, 1984-, et al.
(författare)
-
Molecular Characterization of Clinically Relevant Extended-Spectrum beta-Lactamases bla(CTX-M-15)-Producing Enterobacteriaceae Isolated from Free-Range Chicken from Households in Bangladesh
- 2022
-
Ingår i: Microbial Drug Resistance. - : Mary Ann Liebert Inc. - 1076-6294 .- 1931-8448. ; 28:7, s. 780-786
-
Tidskriftsartikel (refereegranskat)abstract
- The study explored the potential colonization and characterization of extended-spectrum beta-lactamase (ESBL)-producing Enterobacteriaceae in the gut of free-range poultry from the rural households in Bangladesh. From 48 households located in several rural regions (eastern, western, and southern) of Bangladesh, 180 poultry fecal samples were collected to isolate ESBL-producing Enterobacteriaceae. ESBL producers were characterized by susceptibility testing, conjugation experiment, conventional polymerase chain reactions (PCRs), and multilocus sequence typing (MLST) followed by sequencing. Total 23% (42/180) poultry were ESBL positive consisting of Escherichia coli (n = 41) and Klebsiella pneumoniae (n = 1). ESBL producers were resistant to Cefotaxime (CTX; 100%), Cefepime (100%), Amoxicillin-clavulanic acid (36%), Ciprofloxacin (31%), and Trimethoprim-sulfamethoxazole (24%), and 12% isolates were multidrug resistant. All ESBL producers were carrying bla(CTX-M-15)-like genotype.Isolates were also carrying genes for quinolone resistance [qnrS1, aac(6 ')-Ib-cr], silver resistance (silE), and mercury resistance (merA). Isolates were negative for 025b-ST131 clone, mcr-1, and bla(OXA-48) gene. The repetitive element PCR revealed 15 different clones of E. coli and some of these clones were found to be common in 3 sampling locations. MLST analysis of E. coli revealed 9 different sequence types (STs); ST4, ST156, ST542, ST1140, ST1290, ST4628, ST5114, ST9768, and ST11317. ESBL producers were carrying transferable plasmids and 4 different plasmid replicon types; IncI1 (29%), IncY (7%), IncFIB (7%), and IncF1A (5%). The findings from the study confirmed that free-range poultry are potential ESBL carriers with coresistance to other antibiotic classes, metals, and biocides. This study confirms that free-range poultry in Bangladesh living close to humans without any direct antibiotic exposure could carry ESBL bacteria. Free-range poultry could be reservoir as well as a potential spreader of pathogenic E. coli and antibiotic- or biocide-resistant genes.
|
|
| 11. |
- Hasan, Badrul, 1984-, et al.
(författare)
-
The Gull (Chroicocephalus brunnicephalus) as an Environmental Bioindicator and Reservoir for Antibiotic Resistance on the Coastlines of the Bay of Bengal
- 2014
-
Ingår i: Microbial Drug Resistance. - : Mary Ann Liebert Inc. - 1076-6294 .- 1931-8448. ; 20:5, s. 466-471
-
Tidskriftsartikel (refereegranskat)abstract
- The presence and frequency of multiresistant bacteria in wild birds act as indicators of the environmental contamination of antibiotic resistance. To explore the rate of contamination mediated by Escherichia coli, 150 fecal samples from the brown-headed gull (Chroicocephalus brunnicephalus) and 8 water samples from the Bay of Bengal area were collected, cultured, and tested for antibiotic susceptibility. Special attention was paid to extended-spectrum beta-lactamase (ESBL)-producing isolates, which were further characterized genetically. Antibiotic resistance was found in 42.3% (36/85) of the E. coli isolates and multidrug resistance in 11.8%. Isolates from the area with a higher human activity were more resistant than those from an area with a lower level of activity. Most frequent was resistance to ampicillin (29.4%), followed by trimethoprim-sulfamethoxazole (24.7%) and quinolones (22.4%). Carriage of ESBL-producing E. coli was relatively high (17.3%) in the gulls, whereas no ESBL producers were found in the water. All ESBL-producing E. coli isolates, but one, carried blaCTX-M-15 or blaCTX-M-15-like genes. A blaCTX-M-14-like enzyme was found as an exception. Gulls from two different colonies shared E. coli clones and harbored the clinically relevant sequence types ST10, ST48, and ST131. The high frequency of antibiotic resistance and ESBL production among E. coli isolates from gulls indicates that the environmental contamination of antibiotic resistance has already gone far on the coastlines of the Bay of Bengal. Considering the limited control over the antibiotic consumption and waste from human activities in Bangladesh, there is no easy solution in sight.
|
|
| 12. |
|
|
| 13. |
- Hessman, Jon, et al.
(författare)
-
High Prevalence and Temporal Variation of Extended Spectrum β-Lactamase–Producing Bacteria in Urban Swedish Mallards
- 2018
-
Ingår i: Microbial Drug Resistance. - : Mary Ann Liebert Inc. - 1076-6294 .- 1931-8448.
-
Tidskriftsartikel (refereegranskat)abstract
- Antibiotic resistant bacteria present a growing global healthcare challenge. Previous research demonstrates that wild birds harbor extended spectrum -lactamase (ESBL)-producing Enterobacteriaceae and may contribute to their dissemination. We aimed to assess prevalence and temporal variation in the detection rate of ESBL-producing bacteria in urban wild birds and to evaluate methods regarding sample handling. Monthly fecal sampling was performed in 2013 at an urban pond in Sweden. ESBL-producing Escherichia coli and Klebsiella pneumoniae were analyzed by polymerase chain reaction targeting bla(CTX-M). Subsets of samples were analyzed in multiple replicates and without previous freezing. Pond water samples were screened for 12 antibiotics. Out of 813 fecal samples, 47% grew ESBL-producing E. coli, a higher prevalence than in similar studies. Detection rate varied considerably between months, ranging from 4.2% in May to 84% in July, and was significantly higher during warm months. A majority of isolates harbored CTX-M-15 type ESBL. Detection rates were increased by duplicating samples and by avoiding freezing. No antibiotics were detected in pond water. This study demonstrates high prevalence and a previously undescribed temporal variation in detection rate of ESBL-producing Enterobacteriaceae in wild birds. The distribution of CTX-M genes corresponds well with Swedish human isolates, indicating communication between the genetic pools of ESBLs in humans and wild birds. Urban ponds may serve as important natural reservoirs for antimicrobial resistance.
|
|
| 14. |
|
|
| 15. |
- Hogberg, L, et al.
(författare)
-
Penicillin-resistant pneumococci in Sweden 1997-2003: Increased multiresistance despite stable prevalence and decreased antibiotic use
- 2006
-
Ingår i: Microbial Drug Resistance. - : Mary Ann Liebert Inc. - 1076-6294 .- 1931-8448. ; 12:1, s. 16-22
-
Tidskriftsartikel (refereegranskat)abstract
- Antimicrobial resistance patterns and capsular groups of penicillin-resistant Streptococcus pneumoniae (PRP; MIC penicillin G >= 0.5 mg/ml) in Sweden between 1997 and 2003 were described, and trends in resistance and antibiotic sales during the same period were compared. The most common serogroups were in descending order 9, 19, 14, 23, and 6. Despite a low and stable annual PRP rate (proportion of PRP out of all pneumococci) of around 2% during the study period, the proportion of PRP resistant to other antibiotics increased. Of all tested PRP isolates, 82% were also resistant to trimethoprim/sulfamethoxazole, 32% had additional resistance to tetracycline, and 26% to erythromycin. Antibiotic sales figures for all studied antibiotic subgroups decreased during the same period. Little correlation was found between antibiotic sales and PRP resistance rates, indicating that there are still other poorly defined factors contributing to the reported resistance levels in the population. However, although PRP strains in Sweden are becoming more commonly resistant to antibiotics other than beta-lactams, the low and further reduced antibiotic sales still might have delayed the development and rapid spread of PRP in the population.
|
|
| 16. |
- Horcajo, Pilar, et al.
(författare)
-
Peptidoglycan plasticity in bacteria : stress-induced peptidoglycan editing by noncanonical D-amino acids
- 2012
-
Ingår i: Microbial Drug Resistance. - : Mary Ann Liebert Inc. - 1076-6294 .- 1931-8448. ; 18:3, s. 306-313
-
Tidskriftsartikel (refereegranskat)abstract
- It has been generally assumed that the role of D-amino acids in bacterial physiology is rather limited. However, recent new evidence demonstrated that millimolar concentrations of noncanonical D-amino acids are synthesized and released to the environment by bacteria from diverse phyla. These D-amino acids help bacteria adapt to environmental challenges by modulating the structure and composition of the peptidoglycan (PG). This regulation, which appears to be well conserved among bacterial species, occurs principally through the incorporation of the D-amino acids into the terminus of the peptide moiety of muropeptides. These findings revived interest in studies investigating D-amino acids as an exciting and trendy topic in current microbiology, which considers them as fundamental players in different aspects of bacterial physiology. In this article, we provide an overview of the origins of research on the effects of D-amino acids in the biology of bacterial cell walls, including their recent implication as key factors for stress-associated PG remodeling.
|
|
| 17. |
|
|
| 18. |
|
|
| 19. |
- Kaarme, Johan, et al.
(författare)
-
Zero Prevalence of Vancomycin-Resistant Enterococci Among Swedish Preschool Children
- 2015
-
Ingår i: Microbial Drug Resistance. - : Mary Ann Liebert Inc. - 1076-6294 .- 1931-8448. ; 21:1, s. 65-68
-
Tidskriftsartikel (refereegranskat)abstract
- Objectives: Enterococci are a natural part of the bacterial flora of humans, animals, and insects and are frequently found in the community. Vancomycin-resistant enterococci (VRE) have emerged as a growing problem, associated with high morbidity and mortality. The aim of this study was to investigate the prevalence of VRE among healthy Swedish preschool children and ascertain whether they constitute a reservoir for the bacteria.Methods: In total, 313 individual diapers were collected from preschools in Uppsala, Sweden. Fecal samples were screened by analyzing the color change in a broth followed by polymerase chain reaction for vanA and vanB genes, which are associated with vancomycin resistance.Results: Neither vanA nor vanB genes could be detected from the samples.Conclusions: Preschool children in Uppsala do not constitute a reservoir for VRE. The zero prevalence is consistent with the overall decline in VRE prevalence in Sweden during the last years.
|
|
| 20. |
|
|
| 21. |
|
|
| 22. |
- Lupo, Agnese, et al.
(författare)
-
Is blaCTX-M-1 Riding the Same Plasmid Among Horses in Sweden and France?
- 2018
-
Ingår i: Microbial Drug Resistance. - : Mary Ann Liebert. - 1076-6294 .- 1931-8448. ; 24:10, s. 1580-1586
-
Tidskriftsartikel (refereegranskat)abstract
- A predominance of the blaCTX-M-1/IncHI1 plasmid combination in horses has been reported in Czech-Republic, Denmark, and The Netherlands. To clarify a possible specific plasmid epidemiology of blaCTX-M-1 in horses in a European perspective, a collection of 74 extended-spectrum beta-lactamase-producing Escherichia coli recovered from diseased horses in France and Sweden during the period 2009-2014 was investigated in respect of their genetic relatedness, plasmid content, and molecular features.Overall, 80% of E. coli isolates from diseased horses harbored blaCTX-M-1 on large IncHI1 plasmids with plasmid sequence type (pST) 2 and pST9 more prevalent in Sweden and France, respectively. In French isolates, IncI1/pST3 plasmids were also identified. The CTX-M-1-producing E. coli belonged principally to the clonal complex 10. ST641, together with its single locus variant, and ST1730 constituted two other major groups. The rep-PCR clustering highlighted a clonal dissemination of E. coli CTX-M-1 producers in different regions of the same country and during several years.The STs found in our isolates were also reported in The Netherlands, suggesting a common source of contamination in Europe, although only further cooperative investigation will clarify this issue. On the other hand, the spread of IncI1/pST3 plasmids among horses constitutes another worrisome issue considering their successful spread in other animal hosts such as chicken or bovines.Monitoring evolution and propagation of antimicrobial resistance in equine environment is a priority to avoid further propagation of antimicrobial resistance mechanisms threatening human and animal health.
|
|
| 23. |
|
|
| 24. |
|
|
| 25. |
|
|
| 26. |
|
|
| 27. |
|
|
| 28. |
|
|
| 29. |
- Prellner, Karin, et al.
(författare)
-
Immunization and protection in pneumococcal otitis media studied in a rat model
- 1999
-
Ingår i: Microbial Drug Resistance. - 1076-6294 .- 1931-8448. ; 5:1, s. 73-82
-
Tidskriftsartikel (refereegranskat)abstract
- The recent and growing problem of bacterial resistance to common antibiotics has generated great interest in different methods for prevention of infections. The treatment of the pathogens causing upper airway infections and especially acute otitis media (AOM) is especially interesting in this context because these infections are a common cause of prescription of antibiotics all over the world. Both in AOM and recurrent AOM, Streptococcus pneumoniae, the most frequently occurring bacterium is isolated in 30-50% of all AOM attacks. In the last decade, multiresistant S. pneumoniae have emerged as a major problem. Thus, it is important to explore possibilities that immunization may protect against pneumococcal OM. In a well-defined animal model using Sprague-Dawley rats, we have investigated the effects of different routes of immunization with different antigens and whole cells. Together with otomicroscopical evaluation of middle ear (ME) status, samples for bacterial cultivation as well as for studies of histopathological changes have been collected. Antibody titers have been followed during and after pneumococcal AOM by an enzyme-linked immunosorbent assay (ELISA) method.
|
|
| 30. |
- Saffari, Fereshteh, et al.
(författare)
-
Molecular and Phenotypic Characterization of Multidrug-Resistant Clones of Staphylococcus epidermidis in Iranian Hospitals : Clonal Relatedness to Healthcare-Associated Methicillin-Resistant Isolates in Northern Europe
- 2016
-
Ingår i: Microbial Drug Resistance. - : Mary Ann Liebert Inc. - 1076-6294 .- 1931-8448. ; 22:7, s. 570-577
-
Tidskriftsartikel (refereegranskat)abstract
- The aim of the study was to investigate the molecular epidemiology of Staphylococcus epidermidis in Iranian hospitals and to compare the genotypes with a previously characterized collection of >1,300 S. epidermidis isolates of nosocomial and community origin from Northern Europe, Australia, and USA. In total, 82 clinical S. epidermidis isolates from three Iranian hospitals were examined by multilocus sequence typing, pulsed-field gel electrophoresis (PFGE) and staphylococcal cassette chromosome mec (SCCmec) typing. In addition, antimicrobial susceptibility, the presence of the ica operon, and the predilection to biofilm formation were assessed. Three predominant PFGE clones were found. The PFGE patterns of the most common sequence type (PFGE type 040-ST2) showed 80% similarity to multidrug-resistant S. epidermidis (MDRSE) clinical isolates from eight hospitals in Northern Europe. The second most common (PFGE 024-ST22) showed an unique PFGE pattern, whereas the third most predominant genotype (PFGE 011-ST5) proved indistinguishable to the PFGE Co-ST5 identified in five hospitals in Northern Europe. In conclusion, the study documented the dissemination of three MDRSE clones within and between hospitals in Iran and revealed an intercontinental spread of two clonal multidrug-resistant lineages (ST2 and ST5) in the hospital environment. Isolates of the predominant clones were significantly more frequently associated with multidrug-resistance and biofilm formation compared to nonclonal isolates. Further studies are needed to explore and characterize the genetic traits that enable these successful MDRSE clones to persist and disseminate worldwide in the healthcare settings.
|
|
| 31. |
- Tegnell, Anders, et al.
(författare)
-
Study of developed resistance due to antibiotic treatment of coagulase-negative Staphylococci.
- 2003
-
Ingår i: Microbial Drug Resistance. - : Mary Ann Liebert Inc. - 1076-6294 .- 1931-8448. ; 9:1, s. 1-6
-
Tidskriftsartikel (refereegranskat)abstract
- Coagulase-negative Staphylococci (CoNS) are a major cause of postoperative infections. These infections are often associated with foreign material implants and/or a compromised immune system in the patient. Multiresistant strains are increasingly common in the hospital environment and there is concern that the infections will become difficult or impossible to treat. This report is based on a study of 75 patients, with postoperative infections caused by CoNS after thoracic surgery. All patients were treated with surgical revision and antibiotic therapy. One or more bacterial cultures were made in each case, and the resistance pattern of the CoNS found was determined. The goal of the study was to evaluate possible relationships between antibiotic therapy and the appearance of resistance to antibiotics in CoNS found. To describe this relationship, three models were constructed and analyzed by multiple logistic regression. The results indicate an increased resistance to beta-lactam antibiotics and clindamycin after the use of cephalosporins. Also, the use of vancomycin or vancomycin in combination with rifampicin or fusidic acid increases the risk for development of resistance to beta-lactam antibiotics, ciprofloxacin, fusidic acid, clindamycin, netilmycin, and rifampicin. The hypothesis that a combination of antibiotics will curtail the development of resistance was not supported in this study.
|
|
| 32. |
|
|
| 33. |
- Zhou, Ziyu, et al.
(författare)
-
Emergence of IncX3 Plasmid-Harboring bla(NDM-5) in a Citrobacter sedlakii Isolated from Outdoor Aerosol in Wastewater Treatment Plant
- 2022
-
Ingår i: Microbial Drug Resistance. - : MARY ANN LIEBERT, INC. - 1076-6294 .- 1931-8448. ; 28:2, s. 199-204
-
Tidskriftsartikel (refereegranskat)abstract
- A carbapenem-resistant Citrobacter sedlakii strain AA2CS carrying bla(NDM-5) was detected in outdoor aerosols of a wastewater treatment plant (WWTP) in China and the whole genome was sequenced subsequently. AA2CS was captured in an aerobic tank with aerosol particles of sizes ranging from 4.7 to 7.0 mu m. Besides bla(NDM-5), AA2CS also harbored 21 other antibiotic resistance genes and displayed a high level of resistance to ampicillin, cefotaxime, ceftazidime, tetracycline, and meropenem. Bla(NDM-5) was located on the IncX3 plasmid (pCSNDM-5) with an IS3000-IS5-bla(NDM-5)-ble(MBL)-trpF-dsbD-IS26 structure. pCSNDM-5 was highly homologous to other bla(NDM-5)-carrying IncX3 plasmids in China and can be transferred to the Escherichia coli recipient J53. To our knowledge, this is the first report of carbapenem-resistant Enterobacteriaceae in outdoor aerosols in WWTPs.
|
|
| 34. |
- Zou, Huiyun, et al.
(författare)
-
Evaluating Dissemination Mechanisms of Antibiotic-Resistant Bacteria in Rural Environments in China by Using CTX-M-Producing Escherichia coli as an Indicator
- 2019
-
Ingår i: Microbial Drug Resistance. - : Mary Ann Liebert, Inc., publishers. - 1076-6294 .- 1931-8448. ; 25:7, s. 975-984
-
Tidskriftsartikel (refereegranskat)abstract
- It is becoming increasingly recognized that the environment plays an important role both in the emergence and in dissemination of antibiotic-resistant bacteria (ARB), Mechanisms and factors facilitating this development are, however, not yet well understood. The high detection rate of CTX-M genes in environmental sources provides an opportunity to explore this issue. In this study, 88 CTX-M-producing Escherichia coli were isolated from 30 pig feces samples from 30 pig farms and 201 environmental samples. CTX-M-producing E. coli was detected with the following frequencies in the different types of samples: pig feces, 73%; river water, 64%; river sediment, 52%; wastewater, 31%; drinking water, 23%; outlet sediment, 21%; soil, 17%; and vegetables, 4.4%. Dissemination of CTX-M-producing E. coli to different environmental matrices was evaluated by analyzing the genetic relatedness of isolates from different environmental sources, and putative transmission routes through bird feces, pig feces, drinking water, river sediment, river water, and wastewater were hypothesized. Dissemination through these routes is likely facilitated by anthropogenic activities and environmental factors. Wild birds as potential vectors for dissemination of CTX-M-producing E. coli have the capacity to spread ARB across long distances. Regional dissemination between different environmental matrices of CTX-M-producing E. coli increases the exposure risk of humans and animals in the area.
|
|
| 35. |
|
|
| 36. |
- Nilsson Wimar, Percy, et al.
(författare)
-
Several different clones present during the penetration phase of resistant Streptococcus pneumoniae in the city of Malmo, Sweden
- 1999
-
Ingår i: Microbial Drug Resistance. - 1076-6294. ; 5:1, s. 37-43
-
Tidskriftsartikel (refereegranskat)abstract
- A rapid increase in the prevalence of Streptococcus pneumoniae with reduced sensitivity to penicillin (MIC > or = 0.12 microgram/mL) was noted among clinical isolates during a 15-month period in 1994-1995 in the city of Malmo, Sweden. All first-time clinical isolates (n = 178) were consecutively collected and investigated for genetic relatedness with BOX-A PCR and arbitrarily primed (AP) PCR. An improved method for chromosomal DNA extraction and the use of three reliable discriminatory primers for AP-PCR of S. pneumoniae are described. Using molecular fingerprinting, 30 different genotypes were discerned among the 178 isolates. The majority (87%) of isolates belonged to serogroups 6, 9, 15, 19, and 23. Resistance patterns and serogrouping indicated the presence of at least three major phenotypic clones. DNA fingerprinting in conjunction with minimum inhibitory concentration (MIC) values, resistance patterns, and epidemiological data confirmed the existence of two clones belonging to serogroups 6 and 9. Of the 178 isolates, 82% were from children of preschool age, most of whom attended day-care centers. We conclude that abundant S. pneumoniae strains with MICs > or = 0.12 microgram/mL for penicillin were present in the city of Malmo during the study period. At least two genetically discrete clones causing clinical illness were identified, and attendance at day-care centers may be a major factor in the spread of these strains.
|
|
