ABSTRACT
More than 900 cases of scarlet fever were recorded in Hong Kong during January-July, 2011. Six cases were complicated by toxic shock syndrome, of which 2 were fatal. Pulsed-field gel electrophoresis patterns suggested a multiclonal epidemic; emm12 was the predominant circulating type. We recommend genetic testing of and antimicrobial resistance monitoring for this reportable disease.
Subject(s)
Epidemics , Scarlet Fever/epidemiology , Streptococcus pyogenes/genetics , Anti-Bacterial Agents/pharmacology , Child , Electrophoresis, Gel, Pulsed-Field , Female , Hong Kong/epidemiology , Humans , Incidence , Microbial Sensitivity Tests , Scarlet Fever/complications , Scarlet Fever/microbiology , Shock, Septic/epidemiology , Shock, Septic/etiology , Streptococcus pyogenes/drug effectsSubject(s)
Bacterial Proteins/metabolism , Enterobacteriaceae/drug effects , Enterobacteriaceae/enzymology , beta-Lactamases/metabolism , Aged , Anti-Bacterial Agents/pharmacology , Drug Resistance, Multiple, Bacterial , Enterobacteriaceae/classification , Enterobacteriaceae/isolation & purification , Enterobacteriaceae Infections/diagnosis , Enterobacteriaceae Infections/microbiology , Female , Hong Kong , Humans , Male , Microbial Sensitivity Tests , Middle AgedABSTRACT
AIMS: The aim of this study was to characterise clinical and microbiological features of isolates obtained from both invasive and non-invasive Streptococcus pyogenes infections in Hong Kong, between October 2005 and April 2008. METHOD: Clinical data of invasive isolates were collected retrospectively. Altogether 281 isolates were emm sequence typed and tested for antimicrobial susceptibility using disk diffusion method. Detection of the presence of the streptococcal pyrogenic exotoxin genes was also carried out. RESULTS: emm1, emm4 and emm12 were the most prevalent in both the invasive and non-invasive groups with an increase in incidence of emm22 compared with a previous study. emm22 was associated with invasive cellulitis and wound infection. The overall rate of erythromycin resistance was 25.6% and was significantly higher in emm22 strains (85.7%). The phage-encoded superantigen gene speA was exclusively associated with emm1 in both invasive and non-invasive isolates. CONCLUSION: This study revealed a changing epidemiology of S. pyogenes infection in Hong Kong, with a unique pattern compared with other Asian countries. Invasiveness is not related to the presence of speA, speC or ssa genes and the antimicrobial resistance rate was high for macrolides. The findings have an implication on the use and efficacy of the polyvalent S. pyogenes vaccine under development.
Subject(s)
Drug Resistance, Microbial/genetics , Streptococcal Infections/epidemiology , Streptococcal Infections/microbiology , Streptococcus pyogenes/isolation & purification , Anti-Bacterial Agents/pharmacology , Bacterial Outer Membrane Proteins/genetics , Bacterial Proteins/genetics , Drug Resistance, Microbial/drug effects , Erythromycin/pharmacology , Exotoxins/genetics , Genes, Bacterial/genetics , Hong Kong/epidemiology , Humans , Membrane Proteins/genetics , Microbial Sensitivity Tests , Molecular Epidemiology , Retrospective Studies , Streptococcal Infections/blood , Streptococcus pyogenes/genetics , Superantigens/geneticsSubject(s)
Gram-Positive Bacterial Infections/diagnosis , Adult , Anti-Bacterial Agents/therapeutic use , Bacteria, Anaerobic , Endometriosis/complications , Endometriosis/microbiology , Female , Gram-Positive Bacteria , Gram-Positive Bacterial Infections/drug therapy , Hong Kong/epidemiology , Humans , Male , Middle Aged , Ovarian Cysts/complications , Ovarian Cysts/microbiology , Treatment Outcome , Vagina/microbiologySubject(s)
Acinetobacter Infections/epidemiology , Acinetobacter Infections/microbiology , Acinetobacter baumannii/genetics , Anti-Bacterial Agents/therapeutic use , Drug Resistance, Bacterial/genetics , beta-Lactamases/genetics , Acinetobacter Infections/drug therapy , Acinetobacter baumannii/drug effects , DNA, Bacterial/analysis , DNA, Bacterial/genetics , Hong Kong/epidemiology , HumansSubject(s)
Anti-Bacterial Agents/pharmacology , Clindamycin/pharmacology , Erythromycin/pharmacology , Streptococcus suis/drug effects , Tetracycline/pharmacology , Bacterial Typing Techniques/methods , Hong Kong , Hospitals , Humans , Microbial Sensitivity Tests , Serotyping , Streptococcal Infections/microbiology , Streptococcus suis/classification , Streptococcus suis/isolation & purificationABSTRACT
In an attempt to assess the level of quinolone resistance and its association with other antimicrobial resistance in faecal Escherichia coli isolated from routine outpatient specimens in Hong Kong, ciprofloxacin-supplemented MacConkey agar was used to screen for resistant isolates. Antimicrobial susceptibility testing of the isolates was done by VITEK 2 and previous amplification-based methods were employed to characterize the genetic determinants behind some of the resistance phenotypes. One hundred and seventy-six (43%) of 409 specimens had quinolone-resistant E. coli isolated (199 isolates). Quinolone resistance was found to be associated with resistances to penicillins (>80%) and co-trimoxazole (69%). Nonsusceptibility to combinations of penicillins and clavulanic acid was above 20% and up to 50% for the aminoglycosides gentamicin and tobramycin. CTX-M-type extended-spectrum beta-lactamases were found responsible for most cephalosporin resistances but the transferable quinolone resistance determinant qnrA was not detected. Our data suggested that a high percentage of E. coli isolates as part of the alleged normal intestinal microflora in humans appeared to be resistant to quinolones. Co-resistance to various other frequently used antimicrobials was also observed. Transferable genetic determinants were found to be involved in some cases.
Subject(s)
Drug Resistance, Multiple, Bacterial/drug effects , Escherichia coli Infections/drug therapy , Escherichia coli Infections/microbiology , Escherichia coli/drug effects , Escherichia coli/isolation & purification , Feces/microbiology , Quinolones/therapeutic use , Anti-Bacterial Agents/therapeutic use , Hong Kong , HumansABSTRACT
A rapid pulsed-field gel electrophoresis (PFGE) protocol for subtyping of Streptococcus suis serotype 2 was developed and evaluated using 27 clinical isolates from 22 epidemiologically unrelated patients. Results were matched against antibiogram, virulence genotyping and multi locus sequence typing (MLST). PFGE appeared to be the most discriminatory with numerical index of discrimination (D) equal to 0.87.
Subject(s)
Electrophoresis, Gel, Pulsed-Field/methods , Streptococcus suis/classification , Animals , Anti-Bacterial Agents/pharmacology , Bacterial Proteins/genetics , Bacterial Typing Techniques , DNA, Bacterial/analysis , Humans , Microbial Sensitivity Tests , Serotyping , Streptococcus suis/drug effects , Streptococcus suis/genetics , Streptococcus suis/pathogenicity , Time Factors , Virulence/geneticsABSTRACT
Burkholderia pseudomallei produces an Ambler class A beta-lactamase, known as BPS-1. The beta-lactamase gene from a laboratory-derived, ceftazidime-resistant strain of B. pseudomallei (LH-1-2) was cloned and expressed in Escherichia coli. The beta-lactamase, named BPS-1m, had an identical isoelectric focusing point (pI 7.7) to that of BPS-1, but differed in having a stronger hydrolytic activity against ceftazidime. Susceptibility testing showed that BPS-1m when expressed in E. coli conferred resistance to ceftazidime (MIC >or= 32 mg/L). The amino acid sequence of BPS-1m differed from that of BPS-1 by a Pro-to-Ser change at position 167 in the omega loop.
Subject(s)
Burkholderia pseudomallei/enzymology , Ceftazidime/metabolism , beta-Lactamases/metabolism , Amino Acid Substitution/genetics , Burkholderia pseudomallei/genetics , Burkholderia pseudomallei/isolation & purification , Genetic Variation , Humans , Hydrolysis , beta-Lactam Resistance/genetics , beta-Lactamases/geneticsSubject(s)
Anti-Infective Agents/pharmacology , Burkholderia pseudomallei/drug effects , Burkholderia pseudomallei/isolation & purification , Animals , Fluoroquinolones , Humans , Melioidosis/drug therapy , Melioidosis/microbiology , Microbial Sensitivity Tests/methods , Microbial Sensitivity Tests/statistics & numerical dataABSTRACT
The beta-lactamase gene blaA(BPS) in Burkholderia pseudomallei was cloned and expressed in Escherichia coli. BPS-1 is a cephalosporinase with an isoelectric point of 7.7. Sequence analysis of BPS-1 revealed conserved motifs typical of class A beta-lactamases and a relationship to the PenA (in B. cepacia) and BlaI (in Yersinia enterocolitica) lineages.