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The article discusses a study aimed at determining the prevalence of metallo-B-lactamases (MBLs)-producing Entero-bacteriaceae isolates at a Taiwanese university hospital in 2006 and examining tigecycline activity against MBL producers. It cites the use of 527 Klebsiella pneumoniae, 1026 Escherichia coli and 274 Enterobacter isolates in investigating the prevalence of MBLs in Enterobacteriaceae. The results emphasized the importance of knowing the characteristics of endemic carbapenemase producers before choosing a screening strategy.

Background/purpose: The emergence of multidrug-resistant Neisseria gonorrhoeae is a great challenge in controlling gonorrhea. This study was conducted to survey the prevalence of molecular mechanisms of antimicrobial resistance among 45 clinical isolates of N. gonorrhoeae collected at a university hospital in Southern Taiwan during 1999-2004.Methods: Mutations in mtrR loci and quinolone-resistance-determining regions (QRDRs) were examined by gene sequencing. Polymerase chain reactions with specific primers were performed to detect ermA, ermB, ermC, and ermF. Serogroups and serovars were determined by commercial kits.Results: The percentage of multidrug resistance, that is, resistance to penicillin, tetracycline, erythromycin, and ciprofloxacin, among the 45 isolates was 40%. Ceftriaxone and spectinomycin were active against all isolates in vitro. The frequency of mutations in the QRDR and mtrR promoter was 82.2% and 93.3%, respectively. Eighty-two percent of the isolates carried mutations both in the QRDR and mtrR loci. Of nine mutation profiles with QRDR mutations (n =37), gyrA-Ser91Phe/gyrA-Asp95Gly/parC-Ser87Arg was the most common type (56.8%). Acquired genes for rRNA methylase were detected in 11 isolates (10 ermB and 1 ermA). Twenty-seven serovars were identified and all belonged to serogroup B, which suggested that multiple clones of N. gonorrhoeae were circulating in the community in the Tainan area.Conclusion: The high prevalence of multidrug resistance caused by varied resistance mechanisms in N. gonorrhoeae limits the drug choice. Ongoing surveillance of antimicrobial resistance and discovery of new effective antibiotic therapy are warranted in endemic areas. [ABSTRACT FROM AUTHOR]

Background/purpose: To understand the resistance patterns of rapidly growing mycobacteria (RGM) in Taiwan, antimicrobial resistance of clinical isolates was determined as part of the SMART (Surveillance from Multicenter Antimicrobial Resistance in Taiwan) program.Methods: During the period from January 2002 to December 2003, clinical isolates were collected from eight hospitals located on the west side of Taiwan and one reference laboratory. Broth microdilution minimum inhibitory concentrations of 11 antimicrobial agents were determined for 312 clinical isolates of RGM, including the Mycobacterium fortuitum group (110 isolates), Mycobacterium abscessus group (168 isolates), and Mycobacterium chelonae group (34 isolates).Results: Nearly all of the RGM were susceptible to amikacin and ofloxacin (= 90%) and resistant to doxycycline (less than 3% susceptible). Tobramycin showed similar in vitro activity against the M. fortuitum and M. chelonae (77%) groups, but was less active against the M. abscessus group (58%). Ciprofloxacin was active mainly against M. fortuitum (95%). Nearly all RGM were resistant to erythromycin and doxycycline. However, around half of the RGM isolates remained susceptible to minocycline (50-54%). Clarithromycin was active against the M. abscessus group (53% susceptible), with a high rate of resistance in the M. chelonae (38% susceptible) and M. fortuitum (15% susceptible) group. Cefoxitin was more active against the M. fortuitum group (65%) than the other two RGM (40-44%), and les than 40% of the RGM isolates remained susceptible to imipenem (21-38%).Conclusion: The resistance of RGM in Taiwan is not as high as previously reported (notably for tobramycin, ciprofloxacin and cefoxitin), but reduction in the susceptibility rates of clarithromycin and imipenem for the M. fortuitum and M. abscessus groups demonstrates the importance of in vitro susceptibility testing of clinically important isolates, as susceptibility may differ in different geographical areas, even regionally, and over time. [ABSTRACT FROM AUTHOR]

Abstract: A major concern while prescribing clindamycin to treat infections caused by inducible macrolide, lincosamide, and group B streptogramin (iMLSB)-resistant strains is clinical therapy failure. In this study, we determined the prevalence, mechanism, and clonality of the iMLSB phenotype in oxacillin-resistant Staphylococcus aureus (ORSA) and oxacillin-susceptible S. aureus (OSSA). Among the 729 OSSA isolates collected from July 1995 to March 2006, 72 (10%) were clindamycin sensitive (Clis) and erythromycin resistant (Ermr), and 55 (8%) had the iMLSB phenotype. In the 709 ORSA isolates collected from January 1997 to March 2006, 31 (4%) were Clis and Ermr, and 29 (4%) isolates demonstrated the iMLSB phenotype. In OSSA, ermC was the predominant (51 of 55 isolates) genetic determinant responsible for the iMLSB phenotype, whereas in ORSA, ermA was predominant (27 of 29). Pulsed-field gel electrophoresis showed that 8 pulsed types (RA to RH) were present in ORSA isolates (n = 27), and pulsed type RC was predominant in 17 isolates with 5 identifiable subtypes (RC1 to RC5); this type was prevalent from November 1997 to June 2004. In the OSSA (n = 24) isolates, 14 different pulsed types (SA to SN) were identified, but none was predominant. These results indicate that the incidence of iMLSB resistance phenotype is higher in OSSA than ORSA in Taiwan, and the genetic determinants responsible for the iMLSB phenotype vary in OSSA and ORSA. [Copyright &y& Elsevier]

Summary: Objectives: The objectives of this study were to elucidate the clinical manifestations of Aeromonas infections and the association of putative virulence genes with clinical invasiveness. Methods: 116 consecutive clinical Aeromonas isolates collected from July 1999 to June 2001 in a medical center in southern Taiwan were included. All isolates were identified by biochemical phenotyping and their genomic sequences encoding eight putative virulence factors, including cytolytic enterotoxin (AHCYTOEN), aerolysin (aerA), hemolysin (hlyA), heat-labile enterotoxin (alt), heat-stable enterotoxin (ast), and components of type III secretion system (ascV, aexT and ascF–ascG) were analyzed using polymerase chain reaction and colony blot hybridization. The association of clinical diseases of the patients with the putative virulence genes in the isolates was analyzed. Results: Sixty-two percent of Aeromonas isolates caused clinically evident infections, of which the major clinical manifestations were primary bacteremia (40%), followed by soft tissue infections (27%), and hepatobiliary tract infections (15%). Liver cirrhosis (36%), malignancy (25%), and hepatobiliary diseases (13%) were the major underlying diseases in patients with Aeromonas bacteremia. The majority (64%) of patients with Aeromonas hepatobiliary infections had underlying hepatobiliary diseases, whereas 71% of those with soft tissue infections had antecedent water- or soil-related injuries. The crude fatality rate for Aeromonas infections was 26%. Aeromonas hydrophila complex was the most common (52%) of the three major complex groups investigated, followed by Aeromonas sobria complex (24%) and Aeromonas caviae complex (23%). None of the eight putative virulence factors was associated with invasiveness or bacteremia. Conclusions: Primary bacteremia, soft tissue infections, and hepatobiliary tract infections are the three major clinical manifestations of invasive Aeromonas infections in southern Taiwan. This study found no association between the presence of AHCYTOEN, aerA, hlyA, alt, ast, ascV, aexT or ascF–ascG genes in Aeromonas isolates and the development of extra-intestinal infections or bacteremia. [Copyright &y& Elsevier]

Abstract: A total of 1574 nonduplicate Proteus mirabilis isolates collected at a Taiwanese hospital during 1999 to 2005 were analyzed for production of extended-spectrum β-lactamases (ESBLs). Forty-four ESBL-producing isolates including 22 CTX-M-14, 18 CTX-M-3, 2 CTX-M-24, and 2 CTX-M-66 producers were detected, and the proportion of ESBL producers increased from 0.7% in 1999 to approximately 6% after 2002. CTX-M-66 is a novel variant of CTX-M ESBLs that differs from CTX-M-3 by a Ser to Asn change at amino acid position 23. Coresistances to aminoglycosides and ciprofloxacin were very common in the CTX-M-3 producers. The presence of ArmA-type or RmtB-type 16S rRNA methylase that confers high-level aminoglycoside resistance was detected in 12 CTX-M-3 producers and 4 CTX-M-14 producers. Twenty-four clones including an endemic CTX-M-14–producing clone were observed among the 44 ESBL producers by pulsed-field gel electrophoresis, suggesting that both horizontal transfer and clonal spread contributed to the increased prevalence of bla CTX-M in P. mirabilis. [Copyright &y& Elsevier]

Background/purpose: The aim of this study is to characterize antibiotic-nonsusceptible Salmonella isolates in Taiwan., Methods: A total of 76 Salmonella isolates showing lower susceptibility to cephalosporins or quinolones were identified from 1416 clinical isolates from 1999 to 2008. Minimal inhibitory concentrations for selected antimicrobial agents were tested by the agar dilution method. Antibiotic resistance-related genes were determined by polymerase chain reaction (PCR) combined with sequencing. Southern blotting, conjugation tests, and transformation tests were used to characterize plasmid-mediated quinolone resistance (PMQR) determinants., Results: The observed nonsusceptible phenotypes of 76 isolates were against cefoxitin (57.9%), cefotaxime (43.4%), ceftazidime (40.8%), ceftriaxone (42.1%), cefepime (5.3%), ciprofloxacin (80.3%), and levofloxacin (81.6%). Among 44 cephalosporin-resistant isolates, TEM-1, CMY-2, CMY-14, CTX-M-3-like and CTX-M-15-like determinants were present in 31 (70.5%), 32 (72.7%), 1 (2.3%), 1 (2.3%), and 1 (2.3%) of isolates, respectively. PCR screening for PMQR genes of 62 quinolone-nonsusceptible isolates revealed the presence of qnrS, qnrD, aac(6')-Ib-cr, and oqxAB in 3 (4.8%), 2 (3.2%), 1 (1.6%), and 10 (16.1%) isolates, respectively. Among 36 isolates showing high resistance to quinolones, S83F/D87N and S83F/D87G amino acid substitutions of GyrA were found in 29 (80.6%) and 6 (16.7%) isolates, respectively. Moreover, among quinolone highly resistant isolates, eight (22.2%) of isolates showed over-expression of the PAβN-sensitive efflux pump. Transformants and transconjugants harboring qnrD- or oqxAB-plasmids showed decreased susceptibility to quinolones., Conclusion: GyrA mutations are the major mechanisms associated with quinolone-resistant Salmonella isolates in Taiwan. Overproduction of efflux pump genes and the presence of qnr and oqxAB play additional roles in reduced susceptibility to quinolones., (Copyright © 2015. Published by Elsevier B.V.)

The aim of this study was to characterize fluoroquinolone (FQ)-resistant Escherichia coli isolates from bacteremia in Taiwan in 2001-2015. During the study period, 248 (21.2%) of 1171 isolates were identified as levofloxacin-resistant. The results of phylogenetic group analysis showed that 38.7% of the FQ-resistant isolates belonged to phylogenetic group B2, 23.4% to group B1, 22.6% to groupA, 14.9% to group D, and 0.4% belonged to group F. FQ-resistant isolates were highly susceptible to cefepime (91.5%), imipenem (96.0%), meropenem (98.8%), amikacin (98.0%), and fosfomycin (99.6%), as determined by the agar dilution method. β-lactamases, including blaTEM (66.1%), blaCMY-2 (16.5%), blaCTX-M (5.2%), blaDHA-1 (1.6%), and blaSHV-12 (1.6%), were found in FQ-resistant isolates. The results of PCR and direct sequencing showed that 37 isolates (14.9%) harbored plasmid-mediated quinolone resistance (PMQR) genes. qnrB2, qnrB4, qnrS1, coexistence of qnrB4 and qnrS1, oqxAB, and aac(6')-Ib-cr were found in 1, 4, 4, 1, 15, and 14 isolates, respectively. PMQR genes were successfully transfered for 11 (29.7%) of the 37 PMQR-harboring isolates by conjugation to E. coli C600. These findings indicate that qnr genes remained rare in E. coli but demonstrate the potential spread of oqxAB and aac(6')-Ib-c in Taiwan.

Background: The emergence of imipenem-resistant Pseudomonas aeruginosa (IRPA) has become a great concern worldwide. The aim of this study was to investigate resistance mechanisms associated with bloodstream isolated IRPA strains in Taiwan., Results: A total of 78 non-duplicated IRPA isolates were isolated from patients with bloodstream infection. The average prevalence of imipenem-resistance in those isolates was 5.9 % during a 10-year longitudinal surveillance in Taiwan. PFGE results showed high clonal diversity among the 78 isolates. VIM-2, VIM-3, OXA-10, and OXA-17 β-lactamases were identified in 2 (2.6 %), 3 (3.8 %), 2 (2.6 %), and 1 (1.3 %) isolates, respectively. Active efflux pumps, AmpC β-lactamase overproduction, and extended-spectrum AmpC cephalosporinases (ESACs) were found in 58 (74.4 %), 25 (32.1 %) and 15 (19.2 %) of IRPA isolates, respectively. oprD mutations with amino acid substitution, shortened putative loop L7, premature stop codon caused by point mutation, frameshift by nucleotide insertion or deletion, and interruption by insertion sequence were found in 19 (24.4 %), 18 (23.1 %), 15 (19.2 %), 14 (17.9 %), and 10 (12.8 %) of isolates, respectively., Conclusions: This study suggests that alterations in the OprD protein and having an active efflux pump are the main mechanisms associated with bloodstream isolated IRPA. Overproduction of AmpC, ESACs, and the presence of VIM- and OXA-type β-lactamases play additional roles in reduced susceptibility to imipenem in P. aeruginosa isolates in Taiwan.

The OmpK36 porin plays a role in carbapenem resistance and may contribute to bacterial virulence in Klebsiella pneumoniae. This study aimed to investigate the characteristics of different groups of K. pneumoniae separated by ompK36 typing. Among 226 nonduplicate K. pneumoniae bloodstream isolates collected at a Taiwanese hospital in 2011, four ompK36 types, designated types A, B, C, and D, were identified by PCR in 61, 28, 100, and 36 isolates, respectively; 1 isolate was untypeable. Statistical analysis showed significantly higher rates of antimicrobial resistance (all tested antibiotics except meropenem), extended-spectrum β-lactamases or DHA-1 (47.5% together), Qnr-type quinolone resistance determinants (50.8%), and IncFIIA-type plasmids (49.2%) in group A than in others. Seventeen isolates were identified as belonging to 3 international high-risk clones (4 sequence type 11 [ST11], 10 ST15, and 3 ST147 isolates); all isolates but 1 ST15 isolate were classified in group A. The significant characteristics of group C were hypermucoviscosity (62.0%) and a higher virulence gene content. This group included all serotype K1 (n = 30), K2 (n = 25), and K5 (n = 3) isolates, 6 of 7 K57 isolates, all isolates of major clones associated with pyogenic liver abscesses (29 ST23, 11 ST65, 5 ST86, 7 ST373, and 1 ST375 isolates), and 16 (94.1%) of 17 isolates causing bacteremic liver abscesses. Twelve (42.9%) of the group B isolates were responsible for bacteremic biliary tract infections. Group D was predominant (83.3%) among 12 K20 isolates. This study suggests that most clinical K. pneumoniae isolates can be allocated into four groups with distinct characteristics based on ompK36 types., (Copyright © 2015, American Society for Microbiology. All Rights Reserved.)

Although extended-spectrum-β-lactamase (ESBL)-producing aeromonads have been increasingly reported in recent years, most of them were isolates from case reports or environmental isolates. To investigate the prevalence of ESBL producers among Aeromonas blood isolates and the genes encoding ESBLs, consecutive nonduplicate Aeromonas blood isolates collected at a medical center in southern Taiwan from March 2004 to December 2008 were studied. The ESBL phenotypes were examined by clavulanate combination disk test and the cefepime-clavulanate ESBL Etest. The presence of ESBL-encoding genes, including bla(TEM), bla(PER), bla(CTX-M), and bla(SHV) genes, was evaluated by PCR and sequence analysis. The results showed that 4 (2.6%) of 156 Aeromonas blood isolates, 1 Aeromonas hydrophila isolate and 3 Aeromonas caviae isolates, expressed an ESBL-producing phenotype. The ESBL gene in two A. caviae isolates was bla(PER-3), which was located in both chromosomes and plasmids, as demonstrated by Southern hybridization. Of four patients with ESBL-producing Aeromonas bacteremia, two presented with catheter-related phlebitis and the other two with primary bacteremia. Three patients had been treated with initial noncarbapenem β-lactams for 5 to 10 days, and all survived. In conclusion, ESBL producers exist among Aeromonas blood isolates, and clinical suspicion of ESBL production should be raised in treating infections due to cefotaxime-resistant Aeromonas isolates.

This study was conducted to investigate the prevalence and characteristics of ertapenem-resistant (ETP-R) Klebsiella pneumoniae isolates at a Taiwanese hospital. The disk-diffusion tests revealed that the rate of ertapenem resistance among all isolates collected in 2008 was 13.5%, and the resistance rate among bloodstream isolates increased from 0% to 13.6% between 2001 and 2008. Eighty-two nonduplicate ETP-R isolates collected in 2008 were examined. Seventy-four (90.2%) isolates of them had extended-spectrum β-lactamases (CTX-M- and SHV-type), AmpC enzymes (DHA-1 and CMY-2), and IMP-8 metallo-β-lactamase alone or in combination, and an extremely high prevalence of fluoroquinolone resistance (95.1%) and plasmid-mediated quinolone resistance determinants (90.2%) were also observed. Eighteen ETP-R but imipenem-susceptible isolates were selected and compared with 18 imipenem-nonsusceptible isolates collected before 2008. Sequence analyses revealed genetic disruptions of OmpK36 in 11 imipenem-nonsusceptible and 6 imipenem-susceptible isolates, respectively, and OmpK35 disruptions in 10 isolates for both groups. For the isolates with intact ompK36, sodium dodecyl sulfate-polyacrylamide gel electrophoresis suggests decreased expression of OmpK36 in 5 of 7 imipenem-nonsusceptible isolates and 3 of 12 imipenem-susceptible isolates. In conclusion, the increasing prevalence of ertapenem resistance that was predominantly attributed to noncarbapenemase-mediated resistance mechanisms in K. pneumoniae is becoming a serious treat to patients in Taiwan.

Background/purpose: Identifying the pathogens present in blood stream infections is crucial to initiate appropriate antimicrobial therapy and avoid morbidity and mortality. The aim of this study was to evaluate the effect of overnight storage of aerobic and anaerobic BACTEC 9240 blood culture bottles on the detection time for common pathogens., Methods: From November 2007 to July 2008, a total of 2,105 isolates were positively detected using the BACTEC 9240 system. The time to positive detection (TTD) was calculated by subtracting the time of receipt in the laboratory from the time required to detect a positive culture. The mean TTD values were calculated using the TTD value of the first positive culture bottle only. Overnight delay at the National Cheng Kung University Hospital, Taiwan was 15 hours (from 5 pm to 8 am)., Results: Of the 2,105 total isolates, 972 (46.1%) were Gram-positive bacteria, 1,024 (48.6%) were Gram-negative bacteria and 109 (5.1%) were fungi. Among the top 10 pathogens, 24.7% grew only in the aerobic bottle and 15.1% in the anaerobic bottle, including Staphylococcus spp., Enterococcus faecium, Enterobacteriaceae, and Gram-positive bacilli. Due to the overnight delay in loading a blood culture bottle into the instrument, for most of the pathogens (including Staphylococcus spp. and Enterobacteriaceae), a decrease in TTD by

Background/purpose: An increase in incidence of Clostridium difficile infection (CDI) among Western countries has been noted in recent years. Epidemiological data of CDI are scarce in Taiwan. This study is intended to depict the clinical features of CDI at a medical center in Southern Taiwan., Methods: From January 1, 2007 to March 31, 2008, hospitalized patients with CDI (defined as the presence of gastrointestinal symptoms and fecal C. difficile toxin) were identified. Their medical records were reviewed for further evaluation., Results: A total of 86 cases of CDI were identified in the study period. The incidence was 42.6 cases per 100,000 patient-days, or 3.4 cases per 1,000 discharges, and was highest in intensive care units (110.6 cases per 100,000 patient-days). Variable incidence rates were noted in different wards, and prevalence was higher in the infectious ward. Diarrhea, fever, and abdominal distension were common in 82 (95.3%), 47 (54.7%), and 29 (33.7%) patients, respectively. Metronidazole was the initial therapeutic regimen for 83 (96.5%) patients. Prolonged diarrhea was noted in 31 (36.4%) patients, especially in those on hemodialysis therapy. Recurrence was noted in 7 (8.1%) patients. Fecal carriage of vancomycin-resistant Enterococcus colonization was found in three patients after therapy for CDI. All-cause mortality rate of patients with CDI at 30 days was 23.3%., Conclusion: CDI is increasingly being recognized within the medical departments, and should be considered in hospitalized adults with diarrhea, fever, or abdominal distension alone, or in combination., (Copyright 2010 Taiwan Society of Microbiology. Published by Elsevier B.V. All rights reserved.)

Due to reduced antibiotic consumption in Taiwan, erythromycin resistance rate had decreased in Streptococcus pyogenes, but it increased in Streptococcus pneumoniae. The objectives of the present study were (1) to determine the erythromycin and clindamycin resistance rate and minimum inhibitory concentration (MIC) of the group B streptococcus (GBS) clinical isolates, and (2) to investigate the mechanism responsible for the macrolide, lincosamide, and group B streptogramin (MLS(B)) resistance. A total of 1,395 GBS isolates were collected from June 2001 to April 2007. Forty-four percent of the GBS isolates were resistant to erythromycin, and 39% were resistant to clindamycin. The annual erythromycin resistance rate increased from 32% in 2001 to 51% in 2004; a significant decrease was observed in 2005 (47%), 2006 (42%), and 2007 (38%). Percentage of erythromycin-resistant isolates with erm(B) gene significantly increased from 72% in 2001 to 90% in 2007. We found that the plasmid encoded zeta gene was present in 13% of the resistant isolates, along with erm(B). When compared to our previous study (1991 to May 2001), the overall erythromycin resistance rate increased from 30% to 44%. erm(B) was the major resistant determinant, and zeta toxin encoding plasmid has a limited role in mediating erythromycin resistance unlike in GAS isolates as reported earlier.

Objectives: The aim of this study was to determine the prevalence and characteristics of qnr-carrying Salmonella isolates from humans in southern Taiwan., Methods: A total of 446 Salmonella isolates collected between 2003 and 2006 were screened for qnrA, qnrB and qnrS by PCR experiments. Genetic structures of qnr were determined by PCR-based methods or direct sequencing of plasmid DNA., Results: qnrB2 and qnrS1 were detected in two serovar Enteritidis isolates and two serovar Typhimurium isolates, respectively. One qnrS1-positive isolate was found to produce the CMY-2 AmpC enzyme. qnrS1 was identified on a 10 kb plasmid, which exhibited >99% nucleotide sequence identity with plasmid TPqnrS-1a reported from the UK. qnrB2 was found in a complex sul1-type class 1 integron on a >100 kb plasmid., Conclusions: This study demonstrated the occurrence of qnrB2 and qnrS1 in Salmonella for the first time in Taiwan and characterized their genetic structures.

Objectives: To determine the prevalence and characteristics of bloodstream isolates of Escherichia coli and Klebsiella pneumoniae with qnr genes in a Taiwanese hospital., Methods: A total of 2035 E. coli and 1147 K. pneumoniae isolates collected between 1999 and 2005 were screened for qnrA, qnrB and qnrS by PCR and colony hybridization. Beta-lactamase genes, genetic relatedness and transferability were examined by PCR, PFGE and conjugation, respectively., Results: The prevalence of qnr genes was 7.8% and 0.6% for K. pneumoniae and E. coli, respectively. The prevalence rates of qnrB2, qnrB4 and qnrS1 genes for K. pneumoniae were 2.3%, 3.6% and 2.8%, respectively, and for E. coli were 0.2%, 0% and 0.4%, respectively. The prevalence of qnrB4 in K. pneumoniae increased remarkably from 0% to 7.6% over the 7 study years. qnrA was not detected. Overall, the SHV-5-related, CTX-M-14, CTX-M-3, CMY-2, DHA-1 and IMP-8 beta-lactamases were detected alone or in combination in 82.0% of qnr-positive K. pneumoniae isolates and 41.7% of qnr-positive E. coli isolates. Notably, all qnrB4-positive isolates possessed the DHA-1 enzyme, and the majority of the qnrB2-positive isolates (E. coli, 100%; K. pneumoniae, 80.8%) produced SHV-5-related beta-lactamases. Genetic diversity was demonstrated by PFGE. Conjugation experiments revealed co-transfer of bla(SHV-12), bla(DHA-1) and bla(SHV-5) with qnrB2, qnrB4 and qnrS1, respectively., Conclusions: qnr genes remained rare in E. coli but appeared to be increasing in K. pneumoniae in our hospital. Horizontal transfer may play a major role in the intra-hospital spread of qnr.

Objectives: To investigate characteristics of nine carbapenem-non-susceptible (CP-NS) Escherichia coli isolates collected between 1999 and 2005 at a Taiwanese university hospital., Methods: Genetic relatedness was analysed by PFGE. beta-Lactamases were characterized by PCR and isoelectric focusing. Outer membrane proteins and transcripts were investigated by SDS-PAGE and northern blotting. Cloning experiments were performed to investigate the role of membrane permeability in carbapenem non-susceptibility., Results: The nine CP-NS isolates were found to produce the CMY-2 AmpC enzyme (n = 8), the CTX-M-14-type extended-spectrum beta-lactamase (ESBL) (n = 1), the SHV-12 ESBL (n = 1) and the IMP-8-type metallo-beta-lactamase (n = 1) alone or in combination. All CP-NS isolates revealed a decrease in the transcription and protein expression of ompC, and susceptibility to carbapenems was restored in one isolate by introducing the cloned ompC gene. PFGE revealed genetic diversity among the nine isolates. All patients with the CP-NS isolates had been treated with carbapenems (six patients) and/or extended-spectrum cephalosporins (five patients) before isolation., Conclusions: Our study suggests that the decreased susceptibility to carbapenems in E. coli in the hospital might arise by the stepwise accumulations of multiple drug-resistance determinants in different clones.

Of 1,994 group B streptococcal isolates collected, 26 (1.3%) of the isolates were resistant to levofloxacin, and cross-resistance to other fluoroquinolones was observed. The emergence and prevalence of high-level fluoroquinolone resistance in genetically unrelated isolates were linked to the presence of gyrA, parC, and parE triple mutations in each isolate.

We report a case of rat bite fever caused by Streptobacillus moniliformis in Taiwan. It manifested as prosthetic valve endocarditis, which was cured by cardiac valve replacement and antimicrobial therapy. The DNA sequence of the 16S rRNA gene of S. moniliformis was detected in valve specimens by PCR and nucleotide sequencing.

The prevalence of three plasmid-mediated quinolone resistance determinants, QnrA, QnrB, and QnrS, among 526 nonreplicate clinical isolates of Enterobacter cloacae collected at a Taiwanese university hospital in 2004 was determined by PCR and colony hybridization, and the association of Qnr with the IMP-8 metallo-beta-lactamase was investigated. Eighty-six (16.3%) of all isolates were qnr positive, and the qnrA1-like, qnrB2-like, and qnrS1-like genes were detected alone or in combination in 3 (0.6%), 53 (10.1%), and 34 (6.5%) isolates, respectively. Among 149 putative extended-spectrum-beta-lactamase-producing isolates, 59 (39.6%) isolates, all of which were SHV-12 producers, harbored qnrA (0.7%; 1 isolate), qnrB (28.9%; 43 isolates), or qnrS (12.1%; 18 isolates). Forty-four (78.6%) of 56 IMP-8 producers carried qnrB (58.9%; 33 isolates), qnrS (25.0%; 14 isolates), or both. PCR and sequence analysis revealed that qnrA1 was located in a complex sul1-type integron that contains dhr15, aadA2, qacEDelta1, sul1, orf513, qnrA1, ampR, and qacEDelta1. Conjugation experiments revealed the coexistence of qnrB and bla(IMP-8) on the transferred plasmids and the absence of beta-lactamase content on the transferred qnrS-positive plasmids. The transferred bla(IMP-8)-positive plasmids with and without qnrB had very similar restriction patterns, suggesting the horizontal mobility of qnrB. Pulsed-field gel electrophoresis showed six major patterns among the 44 qnr-positive IMP-8-producing isolates. Thus, the extremely high prevalence of qnr among the metallo-beta-lactamase-producing E. cloacae isolates in the hospital may be due mainly to the intrahospital spread of a few clones and the dissemination of plasmids containing both qnrB and blaIMP-8.

Objectives: The present study was conducted to investigate acquired beta-lactamases and their genetic support in 26 Pseudomonas aeruginosa isolates that were resistant to nearly all antipseudomonal drugs from six medical centres in Taiwan., Methods: Acquired beta-lactamases and their genetic support were determined by PCR-based strategies., Results: Four and 16 of the 26 isolates were found to produce VIM-2 and VIM-3 metallo-beta-lactamases (MBLs), respectively, and 1, 1 and 2 isolates produced OXA-17, OXA-10 and PSE-1, respectively. These bla genes are all in class 1 integrons that are probably chromosomally located. The bla(VIM-3)-containing integron, with a deletion between int1 and the bla(VIM-3) structural gene, has six gene cassettes, bla(VIM-3), a probable fosfomycin resistance determinant, aacA4, aacA4, aadB and aacA4. The bla(VIM-2)-containing integron, without detectable 5'-conserved segment, contains four genes cassettes (aacA7-bla(VIM-2)-dhfr-aacA5) and is ended by tniC. The bla(OXA-10)-containing integron includes a catB3 cassette and a fused gene cassette, which is made up of bla(OXA-17) and a novel streptomycin-spectinomycin gene, designated aadA15. The bla(OXA-17)-containing integron has three gene cassettes (aacA4-catB2-bla(OXA-17)) but the 59-base element of the bla(OXA-17) cassette is interrupted by a putative transposase gene. The bla(PSE-1)-containing integron has three gene cassettes, aacA4, an aadA3-related gene designated aadA3b and bla(PSE-1). PFGE revealed genetic diversity among the multidrug-resistant isolates from different hospitals., Conclusions: This study demonstrated the high prevalence of VIM-type MBLs and the presence of unusual bla-encoding integrons in multidrug-resistant P. aeruginosa isolates in Taiwan. The spread of bla(VIM-2)-related genes by horizontal transfer might have occurred.

Production of extended-spectrum beta-lactamases and plasmid-mediated AmpC enzymes was investigated among 291 Escherichia coli and 282 Klebsiella pneumoniae isolates that showed decreased susceptibilities to extended-spectrum cephalosporins from seven Taiwanese medical centers. CTX-M-type and SHV-type enzymes were the most prevalent extended-spectrum beta-lactamases. CMY-2-like and DHA-1-like beta-lactamases were the most prevalent AmpC-type enzymes.

Background and Purpose: Data on the epidemiology of OXA-type extended-spectrum beta (beta)-lactamases (ESBLs) are limited due to difficulty of identification by routine microbiology laboratories. We determined the prevalence rate of OXA-type beta-lactamases among extended-spectrum cephalosporin (ESC)-non-susceptible Pseudomonas aeruginosa isolates at a university hospital in southern Taiwan., Methods: A total of 1,294 ESC-non-susceptible P. aeruginosa isolates collected between 1989 and 1996 (n = 42) and between December 1999 and December 2002 (n = 1,252) were analyzed by polymerase chain reaction assays with primers specific for bla(OXA) genes and isoelectric focusing., Results: Forty five isolates (3.5%) were found to produce an OXA-type beta-lactamase. Overall, 2 OXA-type ESBLs, OXA-14 (n = 2) and OXA-17 (n = 35), were detected in 37 (2.9%) isolates, and the OXA-10-type narrow-spectrum beta-lactamase was found in 8 (0.6%) isolates. OXA-10 and the 2 OXA-type ESBLs were detected in 6 (14.3%) and 4 (9.5%) of 42 ESC-non-susceptible isolates collected between 1989 and 1996. OXA-10 and OXA-17 were detected in 2 (0.2%) and 33 (2.6%) of 1,252 ESC-non-susceptible isolates collected between December 1999 and December 2002., Conclusions: These data indicate that OXA-17 was the most common OXA-type ESBL and that OXA-type beta-lactamases have decreased in ESC-non-susceptible P. aeruginosa at this hospital in recent years. Pulsed-field gel electrophoresis revealed clonal diversity among the OXA-producing isolates.

We report the prevalence and characteristics of Salmonella strains resistant to ciprofloxacin and extended-spectrum cephalosporins in Taiwan from January to May 2004. All isolates resistant to extended-spectrum cephalosporins carried blaCMY-2, and all ciprofloxacin-resistant Salmonella enterica serotype Choleraesuis isolates were genetically related.

The susceptibilities of nonduplicate isolates to six antifungal agents were determined for 391 blood isolates of seven Candida species, 70 clinical isolates (from blood or cerebrospinal fluid) of Cryptococcus neoformans, and 96 clinical isolates of four Aspergillus species, which were collected in seven different hospitals in Taiwan (as part of the 2003 program of the study group Surveillance of Multicenter Antimicrobial Resistance in Taiwan). All isolates of Candida species other than C. glabrata and C. krusei were susceptible to fluconazole. Among the 59 C. glabrata isolates, 16 (27%) were not susceptible to fluconazole, and all were dose-dependently susceptible or resistant to itraconazole. For three (5.1%) C. glabrata isolates, voriconazole MICs were 2 to 4 microg/ml, and for all other Candida species isolates, voriconazole MICs were /=2 microg/ml were 100% (3 isolates) for C. krusei, 11% (23 of 207 isolates) for Candida albicans, 3.0% (2 of 67 isolates) for Candida tropicalis, 20% (12 of 59 isolates) for C. glabrata, and 0% for both Candida parapsilosis and Candida lusitaniae. For three (4%) Cryptococcus neoformans isolates, fluconazole MICs were >/=16 microg/ml, and two (3%) isolates were not inhibited by 1 mug of amphotericin B/ml. For four (4.2%) of the Aspergillus isolates, itraconazole MICs were 8 microg/ml. Aspergillus flavus was less susceptible to amphotericin B, with the MICs at which 50% (1 microg/ml) and 90% (2 microg/ml) nsrsid417869\delrsid7301351 of isolates were inhibited being twofold greater than those for Aspergillus fumigatus and Aspergillus niger. All Aspergillus isolates were inhibited by

Recently, antimicrobial resistance among nontyphoid Salmonella serotypes has been increasingly recognized. In southern Taiwan, we encountered 3 cases of invasive infections caused by Salmonella enterica serotype Choleraesuis with resistance to ciprofloxacin and ceftriaxone. Resistance to ciprofloxacin was related to nucleotide mutations in gyrA and parC, and resistance to ceftriaxone was related to the presence of CMY-2 beta -lactamase.

Resistance to erythromycin is common among Streptococcus agalactiae in Taiwan, however the genetic relatedness of erythromycin-resistant isolates has not yet been reported. From 1991 to 2001, 629 clinical isolates of S. agalactiae were collected in a medical center at Tainan in southern Taiwan, of which 189 (30.0%) were resistant to erythromycin. The isolation rate of erythromycin-resistant group B streptococcus (GBS) was stable, irrespective of the clinical sources or study period. Among them, 145 (76.7%) isolates showed the macrolide-lincosamide-streptogramin B (MLS)-resistant phenotype, and 44 (23.3%) had the macrolide (M)- resistant phenotype. Of the isolates with MLS phenotype, 141 (97.2%) isolates harbored the ermB gene alone and only three (2.1%) the ermTR gene, whereas 41 (93.2%) of 44 isolates with M phenotype harbored the mefA/E gene. Of 177 typeable isolates, there were 26 unrelated pulsed-field gel electrophoresis (PFGE) patterns. PFGE type 1 accounted for 17.8% (24/135) of MLS phenotype isolates with the ermB gene and 48.7% (18/37) of M phenotype isolates with the mefA/E gene. During the study period, the proportion of PFGE type 6 decreased significantly, whereas that of type 8 increased. Our results suggest that erythromycin resistance is not uncommon among clinical isolates of S. agalactiae and is, at least, partially related to polyclonal spread in southern Taiwan.

Objectives: This study was conducted to investigate the occurrence of 16S rRNA methylases that confer high-level aminoglycoside resistance in Klebsiella pneumoniae and Escherichia coli isolates from two Taiwanese hospitals and the characteristics of these isolates., Methods: A total of 1624 K. pneumoniae and 2559 E. coli isolates consecutively collected over an 18 month period from a university hospital and seven E. coli and eight K. pneumoniae isolates that were resistant to amikacin from a district hospital were analysed. Two 16S rRNA methylase genes, armA and rmtB, were detected by PCR-based assays. beta-Lactamase characteristics were determined by phenotypic and genotypic methods., Results: Overall, 28 armA-positive and seven rmtB-positive isolates were identified, and extended-spectrum beta-lactamases (ESBLs) were detected in 33 (94.3%) isolates. The prevalence rates of armA and rmtB at the university hospital were 0.9% (n=15) and 0.3% (n=5) in K. pneumoniae and 0.4% (n=10) and 0.04% (n=1) in E. coli. CTX-M-3, CTX-M-14, SHV-5-like ESBLs, and CMY-2 were detected alone or in combination in 21, 6, 11, and 2, respectively, of the 28 armA-positive isolates. CTX-M-14 was detected in six of the seven rmtB-positive isolates. Fingerprinting of conjugative plasmids revealed the dissemination of closely related plasmids containing both armA and bla(CTX-M-3). PFGE suggests that armA and rmtB spread by both horizontal transfer and clonal spread., Conclusions: This is the first report of the emergence of 16S rRNA methylases in Enterobacteriaceae in Taiwan. The spread of the multidrug-resistant isolates producing both ESBLs and 16S rRNA methylases may become a clinical problem.

Among 99 clinical Klebsiella pneumoniae isolates resistant to cefoxitin and extended-spectrum cephalosporins, coexistence of AmpC (DHA-1, CMY-2, or CMY-8) and extended-spectrum beta-lactamases (CTX-M and/or SHV) was detected in a total of 35. The remainder produced AmpC (n = 42), extended-spectrum beta-lactamases (n = 9), metallo-beta-lactamases (n = 2), or none of these enzymes (n = 11). Phenotypic characteristics of these isolates were demonstrated.

In an epidemiologic and case-control study including 30 case patients over a 3.5-year period in a Taiwanese university hospital, only beta-lactamase inhibitor use and extended-spectrum cephalosporin use were identified as independent risk factors for nosocomial CMY-2-producing Escherichia coli bloodstream infection, and CMY-2 producers were found more prevalent than extended-spectrum beta-lactamase-producing isolates.

Acute Q fever was previously regarded as an uncommon infectious disease in Taiwan but has been increasingly recognized recently. Acute febrile illness, hepatitis, and pneumonia are the 3 most common manifestations of this condition, whereas jaundice is rarely reported among patients with acute Q fever. We report 2 cases of acute Q fever with jaundice and multi-organ involvement. The first patient presented with fever, severe headache, and acute abdomen necessitating laparotomy and was complicated with acute cholestatic hepatitis, acute non-oliguric renal failure and disseminated intravascular coagulation. The second patient had acute cholestatic hepatitis and thrombocytopenia, and the latter was likely related to the infection of bone marrow by Coxiella burnetii, as evidenced by the presence of C. burnetii DNA detected by nested polymerase chain reaction. The incidence and clinical significance of hyperbilirubinemia was also determined by review of medical records of 35 cases of acute Q fever cases diagnosed serologically at National Cheng Kung University Hospital from 1994 to 2001. All had biochemical hepatitis and 23% had hyperbilirubinemia (serum bilirubin > or =2 mg/dL). The febrile course before admission and the period between the initiation of effective medication to defervescence were longer in patients with hyperbilirubinemia than in patients without hyperbilirubinemia, although this difference was not significant. Our results suggest that the predominant presentation of acute Q fever in southern Taiwan is acute febrile illness with hepatitis and that jaundice is not uncommon. Due to the clinical polymorphism of acute Q fever, the threshold of surveys for C. burnetii infections should be low for febrile patients with elevated transaminases or hyperbilirubinemia of unknown cause.

Twenty-six Escherichia coli isolates recovered from food animal feces and retail ground meats and 14 urinary E. coli isolates from outpatients were shown to carry bla(CMY-2). Similar CMY-2-encoding plasmids were found among seven human and three ground-pork isolates. These data indicate the community spread of bla(CMY-2) in southern Taiwan.

We evaluated the disk susceptibility data of 671 nontyphoid Salmonella isolates collected from different parts of Taiwan from March 2001 to August 2001 and 1,261 nontyphoid Salmonella isolates from the National Taiwan University Hospital from 1996 to 2001. Overall, ciprofloxacin resistance was found in 2.7% (18/671) of all nontyphoid Salmonella isolates, in 1.4% (5/347) of Salmonella enterica serotype Typhimurium and in 7.5% (8/107) in S. enterica serotype Choleraesuis nationwide. MICs of six newer fluoroquinolones were determined for the following isolates: 37 isolates of ciprofloxacin-resistant (human) S. Typhimurium (N = 26) and Choleraesuis (N = 11), 10 isolates of ciprofloxacin-susceptible (MIC <1 mg/mL) (human) isolates of these two serotypes, and 15 swine isolates from S. Choleraesuis (N = 13) and Typhmurium (N = 2) with reduced susceptibility to ciprofloxacin (MIC >0.12 microg/mL). Sequence analysis of the gryA, gyrB, parC, parE, and acrR genes, ciprofloxacin accumulation, and genotypes generated by pulsed-field gel electrophoresis with three restriction enzymes (SpeI, XbaI, and BlnI) were performed. All 26 S. Typhimurium isolates from humans and pigs belonged to genotype I. For S. Choleraesuis isolates, 91% (10/11) of human isolates and 54% (7/13) of swine isolates belonged to genotype B. These two genotypes isolates from humans all exhibited a high-level of resistance to ciprofloxacin (MIC 16-64 mg/mL). They had two-base substitutions in the gyrA gene at codons 83 (Ser83Phe) and 87 (Asp87Gly or Asp87Asn) and in the parC gene at codon 80 (Ser80Arg, Ser80Ile, or Ser84Lys). Our investigation documented that not only did these two S. enterica isolates have a high prevalence of ciprofloxacin resistance nationwide but also that some closely related ciprofloxacin-resistant strains are disseminated from pigs to humans.

Collected between 1993 and 2002 at a Taiwanese university hospital, 77 group A streptococcus isolates associated with scarlet fever were grouped by emm typing and pulsed-field gel electrophoresis. The predominance of an emm1 clone before 1996 and the presence of genetically diverse emm1 and emm4 strains thereafter were found.

Of 384 Salmonella isolates collected from 1997 to 2000 in a university hospital in Taiwan, six ceftriaxone-resistant isolates of Salmonella enterica serovar Typhimurium were found in two patients in 2000. The resistance determinants were on conjugative plasmids that encoded a CMY-2-like cephalosporinase. During the study period, the proportion of CMY-2-like enzyme producers among Escherichia coli increased rapidly from 0.2% in early 1999 to >4.0% in late 2000. Klebsiella pneumoniae isolates producing a CMY-2-like beta-lactamase did not emerge until 2000. The presence of bla(CMY)-containing plasmids with an identical restriction pattern from Salmonella, E. coli, and K. pneumoniae isolates was found, which suggests interspecies spread and horizontal transfer of the resistance determinant. Various nosocomial and community-acquired infections were associated with the CMY-2-like enzyme producers. Our study suggests that the spread of plasmid-mediated CMY-2-like beta-lactamases is an emerging threat to hospitalized patients and the public in Taiwan.

A total of 9082 clinical isolates of Enterobacteriaceae other than Klebsiella spp. collected in 1999 and 2000 at a university hospital in Taiwan were investigated for the production of metallo- beta-lactamases (MBLs). Thirty-six (2.9%) of the 1261 Enterobacter cloacae isolates and one (0.3%) of the 340 Citrobacter freundii isolates were found to carry bla(IMP-8) and bla(VIM-2), respectively, by colony hybridization, PCR and sequence analysis. The IMP-8 producers were recovered from 20 patients and four of them had recently transferred from other hospitals, implying spread of IMP-8-producing E. cloacae among different healthcare settings. Of the 20 non-repetitive IMP-8 producers, 17 (85%) isolates also harboured bla(SHV-12), which was on the same transferable plasmids with bla(IMP-8). The bla(VIM-2)-positive isolate and all non-repetitive bla(IMP-8)-positive isolates appeared susceptible to imipenem (MICs < 8 mg/L) and meropenem (MICs < 4 mg/L), indicating the difficulty in detection of MBLs in Enterobacteriaceae by routine susceptibility testing. Ribotyping of the IMP-8-producing E. cloacae isolates indicated that the dissemination of bla(IMP-8) was due largely to the spread of an epidemic clone, but horizontal transfer among unrelated strains also occurred.

Ten nonrepetitive clinical isolates of Klebsiella pneumoniae exhibiting an unusual inducible beta-lactam resistance phenotype were identified between January 1999 and September 2001 in a university hospital in Taiwan. In the presence of 2 micro g of clavulanic acid, the isolates showed a one to four twofold concentration increase in the MICs of ceftazidime, cefotaxime, and aztreonam but remained susceptible to cefepime (MICs,

Two outbreaks of hand-foot-and-mouth disease (HFMD) occurred in Taiwan between 1998 and 2000. Enteroviruses were isolated from a total of 1,892 patients in this laboratory during this period. Of the virus isolates, enterovirus 71 (EV71) was diagnosed in 44.4% of the patients (132 of 297) in 1998, 2% (13 of 646) in 1999, and 20.5% (195 of 949) in 2000. Genetic analyses of the 5'-untranslated and VP1 regions of EV71 isolates by reverse transcription-PCR and sequencing were performed to understand the diversity of EV71 in these outbreaks of HFMD. Most EV71 isolates from the 1998 epidemic belonged to genotype C, while only one-tenth of the isolates were genotype B. Interestingly, all EV71 isolates tested from 1999 to 2000 belonged to genotype B. This study indicated that two genogroups of EV71 capable of inducing severe clinical illness have been circulating in Taiwan. Furthermore, the predominant EV71 genotypes responsible for each of the two major HFMD outbreaks within the 3-year period in Taiwan were different.