ABSTRACT
Three strains of Burkholderia cenocepacia genomovar IIIA that were polymerase chain reaction positive for cblA, bcrA, and the epidemic strain marker, but were distinct from representatives of ET12 by pulsed-field gel electrophoresis, are described. One of these strains was shown to express cable pili by electron microscopy.
Subject(s)
Bacterial Proteins/genetics , Bacterial Typing Techniques , Burkholderia Infections/microbiology , Burkholderia/classification , Burkholderia/genetics , Burkholderia/isolation & purification , Cluster Analysis , DNA Fingerprinting , Electrophoresis, Gel, Pulsed-Field , Fimbriae, Bacterial/ultrastructure , Genes , Genotype , Humans , Microscopy, Electron, Transmission , Polymerase Chain Reaction/methodsABSTRACT
OBJECTIVES: The aim of this study was to investigate the presence of VEB enzymes among Pseudomonas spp. referred to the UK's national reference laboratory and with phenotypic evidence of extended-spectrum beta-lactamase (ESBL) production. METHODS: Antibiograms were analysed for Pseudomonas spp. referred from November 2003 to November 2007. Isolates with >/=4-fold ceftazidime/clavulanate synergy were screened for bla(VEB) alleles. Genes encoding metallo-beta-lactamases (bla(MBL)) were sought in isolates with positive imipenem/EDTA synergy tests. Selected PCR products were sequenced. PFGE of SpeI-digested genomic DNA was used to compare isolates. RESULTS: Forty-nine (3.7%) of 1338 Pseudomonas spp. were considered potential ESBL producers; 40 were recovered for molecular testing. bla(VEB) alleles were detected in 32 Pseudomonas aeruginosa isolates, comprising diverse PFGE types, from 12 UK hospitals and 1 in India. One UK centre referred 15 isolates with VEB-1 enzyme; these were serotype O15, representing a single PFGE-defined strain that also produced VIM-10 metallo-carbapenemase. This strain was resistant to all beta-lactams, aminoglycosides and ciprofloxacin, remaining susceptible only to colistin (MICs =1 mg/L). Two other P. aeruginosa isolates co-producing both VEB and VIM enzymes were received from two other UK hospitals; one isolate represented inter-hospital spread of the O15 strain and the second was distinct. CONCLUSIONS: VEB enzymes have not been reported previously in the UK, but were produced by 80% of Pseudomonas spp. with phenotypic evidence of ESBL production. They co-existed with VIM carbapenemases in two strains, with one responsible for a major hospital outbreak. The incidence of ESBLs may be underestimated in Pseudomonas because ESBL phenotypes can be masked by other beta-lactam resistance mechanisms.
Subject(s)
Pseudomonas Infections/microbiology , Pseudomonas aeruginosa/enzymology , Pseudomonas aeruginosa/isolation & purification , beta-Lactamases/biosynthesis , Anti-Bacterial Agents/pharmacology , Bacterial Typing Techniques , Cluster Analysis , DNA Fingerprinting , Disease Outbreaks , Drug Resistance, Bacterial , Electrophoresis, Gel, Pulsed-Field , Genes, Bacterial , Genotype , Hospitals , Humans , India , Microbial Sensitivity Tests , Polymerase Chain Reaction/methods , Polymorphism, Restriction Fragment Length , Pseudomonas Infections/transmission , Pseudomonas aeruginosa/classification , Pseudomonas aeruginosa/genetics , Sequence Analysis, DNA , Serotyping , United Kingdom , beta-Lactamases/genetics , beta-Lactams/pharmacologyABSTRACT
BACKGROUND: KPC-type carbapenemases are increasingly prevalent in parts of the USA and Israel and are an emerging concern in South America, Europe and China. We investigated the UK's first two KPC-producing Klebsiella pneumoniae isolates. METHODS: The isolates were referred to the UK's national reference laboratory for confirmation of carbapenem resistance. Susceptibilities were determined by agar dilution, and bla(KPC) and Tn4401-like elements were sought by PCR and sequencing. Isolates were compared by PFGE of XbaI- and SpeI-digested genomic DNA. RESULTS: The isolates were from patients in different UK hospitals, with no epidemiological connection. Both were resistant to carbapenems (MICs > 16 mg/L), with imipenem MICs unchanged by EDTA, and also to all other beta-lactams (including inhibitor combinations), tobramycin, amikacin and ciprofloxacin. They were susceptible to gentamicin (MICs = 1 mg/L) and colistin (MICs = 0.5 mg/L), with intermediate susceptibility to tigecycline (MICs 1-2 mg/L). The isolates belonged to the same PFGE-defined strain, highly related to a disseminated KPC-producing strain characterized previously in Tel Aviv, Israel. Like this Israeli strain, the UK isolates produced KPC-3 carbapenemase, with the bla(KPC-3) gene located within a Tn4401-like element. CONCLUSIONS: The first KPC-3-producing K. pneumoniae isolates detected in the UK were highly genetically related to a KPC-3-producing Israeli K. pneumoniae strain. This relatedness was consistent with the history of one UK patient, who had been hospitalized previously in Israel. However, this strain may be circulating more widely since the second UK patient had no identifiable links with Israel or other overseas countries.
Subject(s)
Bacterial Proteins/biosynthesis , Klebsiella Infections/microbiology , Klebsiella pneumoniae/enzymology , Klebsiella pneumoniae/isolation & purification , beta-Lactamases/biosynthesis , Aged , Anti-Bacterial Agents/pharmacology , Bacterial Typing Techniques , Cluster Analysis , DNA Fingerprinting , Electrophoresis, Gel, Pulsed-Field , Female , Genes, Bacterial , Genotype , Hospitals , Humans , Klebsiella Infections/epidemiology , Klebsiella pneumoniae/classification , Klebsiella pneumoniae/drug effects , Male , Microbial Sensitivity Tests , Polymerase Chain Reaction , United Kingdom/epidemiology , beta-Lactam Resistance , beta-Lactams/pharmacologyABSTRACT
OBJECTIVES: Uropathogenic and invasive Escherichia coli O25:H4-ST131 isolates producing CTX-M-15 extended-spectrum beta-lactamase (ESBL) enzymes have recently been shown to be disseminated across the globe. In the UK, many CTX-M-15 ESBL-producing E. coli strains have been previously defined as belonging to the epidemic strains A-E, as determined by PFGE. The present study was carried out to define the relationship between these two groups of pathogenic E. coli. METHODS: Multilocus sequence typing and PFGE were used for molecular characterization of a collection of 61 ESBL-producing E. coli isolates from across the UK. RESULTS: Strains A to E all belonged to the ST131 clone, further underscoring the epidemiological importance of this lineage. CONCLUSIONS: The future spread of the ST131 clone, and its UK variants, should be monitored closely and the pathogenic mechanisms explaining their success should be investigated.
Subject(s)
Escherichia coli Infections/epidemiology , Escherichia coli Infections/microbiology , Escherichia coli/classification , Escherichia coli/isolation & purification , beta-Lactamases/biosynthesis , Bacterial Typing Techniques , Cluster Analysis , DNA Fingerprinting , Electrophoresis, Gel, Pulsed-Field , Escherichia coli/enzymology , Genotype , Humans , Molecular Epidemiology , Sequence Analysis, DNA , Serotyping , United Kingdom/epidemiologyABSTRACT
AIM: A high rate (48.6%) of extended spectrum beta-lactamase production among Klebsiella pneumoniae (ESBL-KP) clinical isolates in the paediatric wards of our hospital prompted the introduction of enhanced infection control measures, and after the implementation of these measures, we instituted a prospective surveillance programme, with a nested case-control study to determine the risk factors for rectal colonisation by ESBL-KP. METHODS: Over a 1-year period, rectal swabs from patients and samples from the environment and the hands of health-care workers were cultured. Strain typing of ESBL-KP isolates was performed using pulsed-field gel electrophoresis. Characteristics of patients who were colonised with ESBL-KP during hospital stay were compared with those of patients who remained negative for ESBL-KP. Multivariate analysis was performed with model-building using stepwise logistic regression to determine independent risk factors for ESBL-KP acquisition. RESULTS: Forty (18.5%) of 216 patients became colonised with ESBL-KP. The strongest independent predictors of ESBL-KP colonisation were mechanical ventilation (odds ratio (OR): 4.28) and hospitalisation for longer than 14 days (OR: 6.97). Genotyping of the isolates indicated probable patient-to-patient transmission; however, we could not determine the route of this spread. During the study period, a 1.6% rate of ESBL-KP clinical infection per 500 patient admissions was observed, in contrast to a 7% rate in the previous year. CONCLUSIONS: Prolonged length of stay and mechanical ventilation were independent predictors of ESBL-KP colonisation. Enhanced infection control measures, antimicrobial stewardship and screening for rectal carriage were associated with a substantial decrease in paediatric units.
Subject(s)
Cross Infection/microbiology , Klebsiella Infections/microbiology , Klebsiella pneumoniae/isolation & purification , beta-Lactamases/biosynthesis , Case-Control Studies , Child , Child, Preschool , Cross Infection/drug therapy , Cross Infection/epidemiology , Electrophoresis, Gel, Pulsed-Field , Equipment Contamination , Female , Hospital Bed Capacity, 300 to 499 , Hospitals, Teaching , Humans , Klebsiella Infections/drug therapy , Klebsiella Infections/epidemiology , Klebsiella Infections/etiology , Klebsiella pneumoniae/drug effects , Klebsiella pneumoniae/genetics , Length of Stay , Male , Microbial Sensitivity Tests , Phenotype , Prospective Studies , Respiration, Artificial , Risk Factors , Turkey/epidemiologyABSTRACT
A multiplex PCR using targets within the serotype-specific region of the capsular polysaccharide synthesis gene cluster of serotypes K1, K2 and K5 was evaluated using the 77 reference serotype strains of Klebsiella, and a panel of clinical isolates subjected previously to conventional serotyping. The PCR was highly specific for these serotypes, which are those most associated with virulence in humans and horses. PCR confirmed that isolates of the K5 serotype had cross-reacted with antiserum for other serotypes, particularly for K7. K5 isolates received by our laboratory were almost exclusively from thoroughbred horses, and were submitted for screening prior to breeding programmes. Most, including a reference strain isolated in 1955, belonged to a cluster of genetically similar isolates of sequence type (ST) 60. K1 isolates, all from humans, belonged to a previously identified cluster of ST 23.
Subject(s)
Klebsiella/classification , Polymerase Chain Reaction/methods , Serotyping/methods , Animals , Antigens, Bacterial , Bacterial Capsules/genetics , Cross Reactions , DNA, Bacterial/isolation & purification , Electrophoresis, Gel, Pulsed-Field , Genes, Bacterial , Horses , Humans , Klebsiella/genetics , Multigene Family , Polysaccharides, Bacterial , Sensitivity and SpecificityABSTRACT
One hundred thirty-eight clinical isolates of the Burkholderia cepacia complex (Bcc) were identified using a modified strategy that involved PCR detection of the cblA gene for the ET12 lineage simultaneously with detection of the Bcc recA PCR product; recA sequence cluster analysis also was part of the strategy. Four strains could not be assigned to any of the known genomovars.
Subject(s)
Burkholderia Infections/microbiology , Burkholderia cepacia complex/classification , Burkholderia cepacia complex/genetics , Bacterial Proteins/genetics , Burkholderia cepacia complex/isolation & purification , Cluster Analysis , DNA Fingerprinting , DNA, Bacterial/chemistry , DNA, Bacterial/genetics , Electrophoresis, Gel, Pulsed-Field , Fimbriae, Bacterial/genetics , Genotype , Humans , Molecular Sequence Data , Polymerase Chain Reaction , Rec A Recombinases/genetics , Sequence Analysis, DNAABSTRACT
The magA gene was sought in hypermucoviscous isolates of Klebsiella spp., the Klebsiella K serotype reference strains and in isolates of the K1 serotype of Klebsiella pneumoniae from the UK, Hong Kong, Israel, Taiwan and Australia. Only K1 isolates were PCR positive for magA; this gene was found in all such isolates tested. Hypermucoviscosity was not confined to magA positive isolates, nor was it found in all magA positive isolates. Comparison of XbaI PFGE profiles revealed that most (19/23) of the magA positive isolates clustered within 72 % similarity, with a further subcluster of isolates, from three different continents, clustering within >80 %. All of the 16 isolates tested within the main cluster had the same sequence type (ST 23) by multilocus sequence typing, with the exception of one isolate, which had a single nucleotide difference at one of the seven loci. This study indicates that a genotype strongly associated with highly invasive disease in Taiwan, where large numbers of cases have been reported, is geographically very widespread.
Subject(s)
Klebsiella Infections/microbiology , Klebsiella pneumoniae/classification , Klebsiella pneumoniae/genetics , Liver Abscess/microbiology , Australia , Bacterial Proteins/genetics , Cluster Analysis , DNA Fingerprinting , DNA, Bacterial/genetics , Deoxyribonucleases, Type II Site-Specific , Electrophoresis, Gel, Pulsed-Field , Genotype , Geography , Hong Kong , Humans , Israel , Klebsiella pneumoniae/isolation & purification , Molecular Epidemiology , Polymerase Chain Reaction , Sequence Analysis, DNA , Sequence Homology , Taiwan , United KingdomABSTRACT
OBJECTIVES: To determine the distribution of acquired AmpC beta-lactamases in 173 isolates of Escherichia coli and Klebsiella spp. submitted to the UK's national reference laboratory for antibiotic resistance. METHODS: MICs were determined and interpreted according to BSAC guidelines. Candidate isolates were those resistant to cefotaxime and/or ceftazidime, irrespective of addition of clavulanic acid. Genes encoding six phylogenetic groups of acquired AmpC enzymes were sought by PCR. Selected isolates were compared by pulsed-field gel electrophoresis (PFGE), and one bla(AmpC) amplicon was sequenced. RESULTS: Genes encoding acquired AmpC enzymes were detected in 67 (49%) candidate E. coli and 21 (55%) Klebsiella spp. Sixty isolates produced CIT-type enzymes, 14 had ACC types, 11 had FOX types and 3 had DHA enzymes. The low-level cephalosporin resistance of the remaining isolates (n = 85; 49%) was inferred to result from reduced permeability or, in E. coli, from hyperexpression of chromosomal ampC. Twenty-four E. coli isolates from one hospital produced a CIT-type enzyme, with 20 of these additionally producing a group 1 CTX-M extended-spectrum beta-lactamase. PFGE indicated that these isolates belonged to UK epidemic strain A, which normally produces CTX-M-15, but no acquired AmpC. Sequencing a representative bla(AmpC) amplicon indicated that in one centre this strain had acquired a novel CMY-2 variant, designated CMY-23. CONCLUSIONS: Diverse acquired AmpC enzymes occur in E. coli and Klebsiella spp. isolates in the UK and Ireland, with CIT types the most common. Producers are geographically scattered, but with some local outbreaks. Acquisition of a CMY-2-like enzyme by E. coli epidemic strain A suggests that these enzymes may be poised to become an important public health issue.
Subject(s)
Bacterial Proteins/genetics , Escherichia coli/enzymology , Klebsiella/enzymology , beta-Lactamases/genetics , Drug Resistance, Bacterial , Escherichia coli/drug effects , Escherichia coli/genetics , Ireland , Klebsiella/drug effects , Klebsiella/genetics , Microbial Sensitivity Tests , United KingdomABSTRACT
OBJECTIVES: To study the clonality of gentamicin-resistant, extended-spectrum beta-lactamase (ESBL)-negative and ESBL-producing Escherichia coli isolated from community-onset urinary tract infections (UTIs) in Cornwall. METHODS: Isolates were identified by API, susceptibilities were determined by local disc testing, and MICs were determined at the reference laboratory, both interpreted using BSAC guidelines. bla(CTX-M) genes were sought by PCR, and isolates were compared by PFGE. RESULTS: In the years 2004 and 2005, 69 E. coli were submitted by Truro (Cornwall) laboratory for reference laboratory testing: these included 14 gentamicin-resistant, ESBL-negative isolates; 45 with group 1 CTX-M enzymes; seven with group 9 CTX-M enzymes; and three with non-CTX-M ESBLs. By PFGE, nine gentamicin-resistant, ESBL-negative E. coli were distinct (<85% similarity) from all the ESBL producers, but three were related to producers of group 1 CTX-M enzymes, and two isolates were related to a non-CTX-M ESBL producer. An outbreak strain was identified, represented by 11 gentamicin-resistant and one gentamicin-susceptible isolates, all with group 1 CTX-M enzymes, and two gentamicin-resistant, ESBL-negative isolates. This was distinct by PFGE from nationally distributed CTX-M-producing strains. Five of nine patients infected with this strain had been on the same ward in a local hospital; four presented with community-onset UTIs; one inpatient developed a hospital-acquired bacteraemia. Of the other four patients presenting with community-onset UTIs, three were admitted to different hospitals and the fourth had only attended an outpatient clinic. CONCLUSIONS: Community-onset, ESBL-producing and non-producing E. coli were diverse. Two ESBL-negative isolates were closely related to a local CTX-M-producing outbreak strain, suggesting gain or loss of a bla(CTX-M)-carrying plasmid. An outbreak strain was linked with prior hospital admission and appeared not to represent genuine community acquisition.
Subject(s)
Community-Acquired Infections/microbiology , Escherichia coli/drug effects , Escherichia coli/genetics , Urinary Tract Infections/microbiology , Disease Outbreaks , Drug Resistance, Multiple, Bacterial , Escherichia coli/enzymology , Escherichia coli Proteins/genetics , Gentamicins/pharmacology , Humans , beta-Lactamases/geneticsABSTRACT
From late 2003 to the end of 2005, the Health Protection Agency's national reference laboratories received approximately 1,600 referrals of Acinetobacter spp., including 419 and 58 examples, respectively, of two carbapenem-resistant Acinetobacter baumannii lineages, designated OXA-23 clones 1 and 2. Representatives of these clones were obtained from 40 and 8 hospitals, respectively, in London or elsewhere in Southeast England. Both clones had blaOXA-23-like genes, as well as the intrinsic (but downregulated) blaOXA-51-like carbapenemase genes typical of A. baumannii. Both were highly multiresistant: only colistin and tigecycline remained active versus OXA-23 clone 1 isolates; OXA-23 clone 2 isolates were also susceptible to amikacin and minocycline. These lineages increase the burden created by the southeast (SE) clone, a previously reported A. baumannii lineage with variable carbapenem resistance contingent on upregulation of the blaOXA-51-like gene. Known since 2000, the SE clone had been referred from over 40 hospitals by the end of 2005, with 627 representatives received by the reference laboratories. The OXA-23 clone 2 is now in decline, but OXA-23 clone 1 continues to be referred from new sites, as does the SE clone. Their spread is forcing the use of unorthodox therapies, principally colistin and tigecycline, although the optimal regimens remain uncertain.
Subject(s)
Acinetobacter Infections/epidemiology , Acinetobacter Infections/microbiology , Acinetobacter baumannii/drug effects , Anti-Bacterial Agents/pharmacology , Carbapenems/pharmacology , Drug Resistance, Multiple, Bacterial , Acinetobacter baumannii/enzymology , Acinetobacter baumannii/genetics , Acinetobacter baumannii/isolation & purification , England , Humans , Microbial Sensitivity Tests , beta-Lactamases/geneticsABSTRACT
bla(OXA-51-like) was sought in clinical isolates of Acinetobacter species in a multiplex PCR, which also detects bla(OXA-23-like) and class 1 integrase genes. All isolates that gave a band for bla(OXA-51-like) identified as A. baumannii. This gene was detected in each of 141 isolates of A. baumannii but not in those of 22 other Acinetobacter species.
Subject(s)
Acinetobacter baumannii/classification , Acinetobacter baumannii/isolation & purification , Bacterial Proteins/genetics , DNA, Bacterial/genetics , Genes, Bacterial , beta-Lactamases/genetics , Acinetobacter baumannii/enzymology , Acinetobacter baumannii/genetics , DNA, Bacterial/analysis , Electrophoresis, Agar Gel , Integrases/genetics , Polymerase Chain Reaction , Sensitivity and SpecificityABSTRACT
Acinetobacter isolates associated with casualties from the Iraq conflict from the United States were compared with those from the United Kingdom by pulsed-field gel electrophoresis and integron analysis. Representatives of the main outbreak strain associated with casualties from both countries were indistinguishable in DNA profile. Two further outbreak strains were common to both sets of isolates.
Subject(s)
Acinetobacter Infections/microbiology , Acinetobacter baumannii/classification , Acinetobacter baumannii/genetics , Military Personnel , Warfare , Acinetobacter Infections/epidemiology , Acinetobacter baumannii/isolation & purification , Cluster Analysis , Cross Infection/epidemiology , Cross Infection/microbiology , DNA Fingerprinting , DNA, Bacterial/genetics , Electrophoresis, Gel, Pulsed-Field , Humans , Integrons/genetics , Iraq , Microbial Sensitivity Tests , Molecular Epidemiology , Polymorphism, Restriction Fragment Length , United Kingdom/epidemiology , United States/epidemiologyABSTRACT
ISAba1 was found in all widespread clones of Acinetobacter baumannii in the United Kingdom. All isolates studied had a blaOXA-51-like carbapenemase gene; some also had blaOXA-23-like and/or blaOXA-58-like. Among isolates with blaOXA-51-like as sole carbapenemase gene, only those with ISAba1 adjacent to blaOXA-51-like were carbapenem resistant. Minor differences in blaOXA-51-like sequence were observed in resistant and susceptible isolates. Isolates with blaOXA-23-like in addition were consistently resistant to carbapenems; in all of these ISAba1 lay upstream of blaOXA-23-like, but was not associated with blaOXA-51-like. These results suggest that ISAba1 is providing the promoter for blaOXA-51-like and, probably, for blaOXA-23-like.
Subject(s)
Acinetobacter baumannii/genetics , Bacterial Proteins/genetics , DNA Transposable Elements/physiology , beta-Lactamases/genetics , Acinetobacter baumannii/enzymology , Polymerase Chain ReactionABSTRACT
The aim of this study was to determine the diversity of Klebsiella pneumoniae capsular serotypes in an Australian setting. Consecutive (n = 293) nonrepetitive isolates of K. pneumoniae from a large teaching hospital laboratory were analyzed. The majority of isolates were from urinary specimens (60.8%); the next most common source was sputum (14.3%), followed by blood (14%). Serotyping revealed a wide range of capsule types. K54 (17.1%), K28 (4.1%), and K17 (3.1%) were the most common, and K54 isolates displayed a high degree of clonality, suggesting a common, nosocomial source. In vitro, one K54 isolate was more adherent to urinary catheters and HEp-2 cells than four other tested isolates; it was slightly more resistant to chlorhexidine but was more susceptible to drying than heavily encapsulated strains. This is the first seroprevalence survey of K. pneumoniae to be performed on Australian isolates, and the high level of diversity of serotypes suggests that capsule-based immunoprophylaxis might not be useful for Australia. In addition there are significant differences in the predominance of specific serotypes compared to the results of surveys performed overseas, which has important implications for capsule-based immunoprophylaxis aimed at a global market.
Subject(s)
Antibodies, Bacterial/blood , Klebsiella Infections/epidemiology , Klebsiella Infections/mortality , Klebsiella pneumoniae/classification , Australia/epidemiology , Bacterial Vaccines/administration & dosage , Bacterial Vaccines/immunology , Hospitals , Humans , Klebsiella Infections/prevention & control , Klebsiella pneumoniae/immunology , Seroepidemiologic Studies , Sputum/microbiology , Terminal Care , Urine/microbiologyABSTRACT
Integrons were sought in Acinetobacter isolates from hospitals in the United Kingdom by integrase gene PCR. Isolates were compared by pulsed-field gel electrophoresis, and most belonged to a small number of outbreak strains or clones of A. baumannii, which are highly successful in the United Kingdom. Class 1 integrons were found in all of the outbreak isolates but in none of the sporadic isolates. No class 2 integrons were found. Three integrons were identified among the main outbreak strains and clones. While a particular integron was usually associated with a strain or clone, some members carried a different integron. Some integrons were associated with more than one strain. The cassette arrays of two of the integrons were very similar, both containing gene aacC1, which confers resistance to gentamicin, two open reading frames coding for unknown products (orfX, orfX'), and gene aadA1a, which confers resistance to spectinomycin and streptomycin. The larger of these integrons had two copies of the first (orfX) of the gene cassettes coding for unknown products. The third integron, with a cassette array containing gene aacA4, which codes for amikacin, netilmicin, and tobramycin resistance; a chloramphenicol acetyltransferase, catB8; and gene aadA1, conferring resistance to spectinomycin and streptomycin, was associated with an OXA-23 carbapenemase-producing clone, which has spread rapidly in hospitals in the United Kingdom during 2003 and 2004. These integron cassette arrays have been found in other outbreak strains of A. baumannii from other countries. We conclude that integrons are useful markers for epidemic strains of A. baumannii and that integron typing provides valuable information for epidemiological studies.
Subject(s)
Acinetobacter Infections/epidemiology , Acinetobacter baumannii/classification , Disease Outbreaks , Integrons/genetics , Acinetobacter Infections/microbiology , Acinetobacter baumannii/drug effects , Acinetobacter baumannii/genetics , Anti-Bacterial Agents/pharmacology , Electrophoresis, Gel, Pulsed-Field , Genotype , Humans , Integrases/genetics , Microbial Sensitivity Tests , Molecular Sequence Data , Polymerase Chain Reaction , Restriction Mapping , Sequence Analysis, DNA , United Kingdom/epidemiologyABSTRACT
Burkholderia multivorans strains from 47 cystic fibrosis (CF) patients in 28 hospitals were compared by pulsed-field gel electrophoresis (PFGE) and flagellin (fliC) PCR-restriction fragment length polymorphism (PCR-RFLP) analysis. A considerable degree of genetic variation was evident, with each patient harboring a strain with a unique PFGE profile. Four sizes of fliC amplicons were produced, and these amplicons gave 13 RFLP types with restriction enzyme MspI. B. multivorans did not appear to spread between patients, suggesting that most CF patients acquire the organism from the natural environment.
Subject(s)
Burkholderia/genetics , Burkholderia/isolation & purification , Cystic Fibrosis/microbiology , Burkholderia/classification , Burkholderia Infections/transmission , Electrophoresis, Gel, Pulsed-Field , Flagellin/genetics , Genetic Variation , Humans , Phylogeny , Polymerase Chain Reaction/methods , Polymorphism, Restriction Fragment Length , United KingdomABSTRACT
Linezolid, the first oxazolidinone antibacterial agent to be developed for clinical use, was licensed in the UK in early 2001. We report the first three examples of resistant enterococci (two isolates of Enterococcus faecium and one Enterococcus faecalis) isolated in the UK, which were obtained from patients who had received linezolid. The linezolid MICs for the resistant isolates were 64 mg/L. Pulsed-field gel electrophoresis (PFGE) analysis of the linezolid-susceptible and -resistant isolates from two of the patients, combined with sequence analysis of rRNA, indicated that resistance developed in previously susceptible strains, most probably via a point mutation in the 23S rRNA.