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Feng-Yee Chang

Publications and source records attributed to Feng-Yee Chang.

At least 37 records · Page 2Linked to original sources
PubMed2004

Mutations of the rpoB gene in rifampicin-resistant Streptococcus pneumoniae in Taiwan.

OBJECTIVE: To determine the mechanism of rifampicin resistance in Streptococcus pneumoniae in Taiwan. METHODS: Rifampicin resistance was investigated with respect to the rpoB gene in 23 invasive S. pneumoniae isolates collected from 1996 to 2001. PCR and molecular typing were used for genetic and epidemiological analyses. Transformation was used to determine the functional gene for resistance. RESULTS: Twenty-two of 23 isolates carried at least one mutation at either cluster I or III of rpoB; the most frequent mutation found in 21 isolates (91%) was histidine (H499) to asparagine or tyrosine at position 499, followed by isoleucine to valine (I624V) at position 624 in 16 isolates (70%), tyrosine to phenylalanine (Y589F) at position 589 in 14 isolates (60.9%) and isoleucine to valine (I608V) at position 608 in 13 isolates (56.5%). Less-frequent mutations were also identified: D489V, R597F, N623E, N623S, N669D, Q671K, Y674F and A683V. High-level rifampicin resistance was observed in isolates with a mutation at position 499 or 489. Mutations other than at position 499 or 489 played little role in or had no relation to rifampicin resistance. No dominant epidemic strain was observed with ribotyping, multilocus sequence typing, or serotyping. CONCLUSIONS: Rifampicin resistance among multidrug-resistant S. pneumoniae in Taiwan was mostly caused by rpoB mutations.

Amino Acid Substitution↗
PubMed2004

High prevalence of phagocytic-resistant capsular serotypes of Klebsiella pneumoniae in liver abscess.

To better understand the role of capsular polysaccharide (CPS) K1 or K2 in Klebsiella pneumoniae liver abscess as well as the development of metastasis to eye, neutrophil phagocytosis of 70 CPS isolates including K1 (n = 23)/K2 (n = 10), non-K1/K2 (n = 37) was evaluated by flow cytometry, fluorescence imaging, and electron microscopy. K1/K2 isolates were significantly more resistant to phagocytosis (P < 0.0001) than non-K1/K2 isolates and displayed increased resistance to intracellular killing. Although mucoid phenotype (M-type) K1/K2 isolates were significantly more resistant to phagocytosis (P = 0.0029) than M-type non-K1/K2, no significant difference in the phagocytosis rate was observed between K1/K2 isolates with M-type and non-M-type (P = 0.0924). Mucoidy is an associated factor that was predominant in K1/K2 isolates, but which itself is not an independent influence on phagocytic resistance. The K1/K2 CPS proved significantly more resistant to phagocytosis than non-K1/K2 CPS in liver abscess isolates (P < 0.0001) and non-abscess isolates (P = 0.0001), suggesting that K1/K2 isolates were generally more virulent in both liver abscess and in non-liver abscess conditions. These findings indicate that resistance of CPS K1 or K2 K. pneumoniae to phagocytosis and intracellular killing presumably contributes to their high prevalence in liver abscess and uniquely in endophthalmitis.

Antigens, Bacterial↗
PubMed2004

Rapid creation of a temporary isolation ward for patients with severe acute respiratory syndrome in Taiwan.

OBJECTIVES: To rapidly establish a temporary isolation ward to handle an unexpected sudden outbreak of severe acute respiratory syndrome (SARS) and to evaluate the implementation of exposure control measures by healthcare workers (HCWs) for SARS patients. DESIGN: Rapid creation of 60 relatively negative pressure isolation rooms for 196 suspected SARS patients transferred from 19 hospitals and daily temperature recordings of 180 volunteer HCWs from 6 medical centers. SETTING: A military hospital. RESULTS: Of the 196 patients, 34 (17.3%) met the World Health Organization criteria for probable SARS with positive results of serologic testing for SARS-associated coronavirus (SARS-CoV), reverse transcriptase polymerase chain reaction (RT-PCR) from nasopharyngeal or throat swabs for SARS-CoV, or both. Seventy-four patients had suspected SARS based on unprotected exposure to SARS patients; three of them had positive results on RT-PCR but negative serologic results. The remaining 88 patients did not meet the criteria for a probable or suspected SARS diagnosis. Of the 34 patients with probable SARS, 13 were transferred to medical centers to receive mechanical ventilation due to rapid deterioration of chest x-ray results, and three patients died of SARS despite intensive therapy in medical centers. During the study period, one nurse developed probable SARS due to violation of infection control measures, but there was no evidence of cross-transmission to other HCWs. CONCLUSIONS: Despite the use of full personal protection equipment, the facility failed to totally prevent exposures of HCWs to SARS but minimized the risk of nosocomial transmission. Better training and improvements in infection control infrastructure may limit the impact of SARS.

Disease Outbreaks↗
PubMed2004

Vancomycin-resistant enterococcus (VRE) carriage and infection in intensive care units.

From July, 1997, through December, 2001, patients who were admitted to intensive care units (ICUs) were enrolled in the study of vancomycin resistance enterococcus (VRE) colonization. Among 4,538 patients admitted to the ICUs, 363 (8.0%) patients were found to have positive culture of VRE at the day of admission to the ICUs and 453 (10.0%) of patients were negative to the first day of admission but became colonized with VRE during the stay in ICU. Among 816 patients, 9 (1.1%) with VRE isolated from sterile sites were selected for further analysis. Pulsed-field gel electrophoresis (PFGE) revealed a total of four PFGE banding patterns in the colonized and infected Enterococcus faecium isolates. Six of nine 9 were found to have an identical PFGE type Ia, suggesting the circulation of an endemic strain. All of these type Ia isolates also contained two potential virulence genes, the esp and hly genes and were first identified in Asia. After the further typing of 540 isolates that were randomly selected from each month, the endemic strain was not identified before the first patient was colonized and infected with this strain in November, 1998, but was isolated from other ICU patients during each month thereafter throughout the remainder of the study period. Although colonization of VRE is the first step toward infection, a low infection rate was observed, except in patients with prolonged hospitalization and severe illness. Use of the isolation room and reminders regarding hand hygiene failed to prevent the circulation of endemic strain. Thus, the SHEA guideline (Muto et al., Infect. Control Hosp. Epidemiol. 2003;24:362-386) for preventing nosocomial transmission of VRE should be enforced.

Bacterial Proteins↗
PubMed2004

Ciprofloxacin-resistant Salmonella enterica Typhimurium and Choleraesuis from pigs to humans, 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.

Adolescent↗
PubMed2004

Patient data, early SARS epidemic, Taiwan.

Of the first 10 patients in the epidemic of severe acute respiratory syndrome (SARS) in Taiwan, 4 were closely associated with a SARS patient in an airplane. Loose stools or diarrhea, hemophagocytosis syndrome, and high serum levels of interleukin (IL)-6, IL-8, and tumor necrosis factor-a associated with lung lesions were found in all 10 patients.

Adult↗
PubMed2004

Community-acquired methicillin-resistant Staphylococcus aureus bacteremia in Taiwan: risk factors for acquisition, clinical features and outcome.

The prevalence of community-acquired infection caused by methicillin-resistant Staphylococcus aureus (MRSA) in Taiwan has increased markedly in the past decade. This study investigated the risk factors for acquisition, the clinical features, and the outcome of community-acquired MRSA bacteremia. Data were collected from records of 86 patients with community-acquired S. aureus bacteremia admitted to a tertiary teaching hospital in Taipei from January 1994 to December 1999. MRSA accounted for 26% (22/86) of isolated pathogens. Over 90% of patients with S. aureus bacteremia had one or more underlying diseases. Significantly more patients with MRSA bacteremia [vs methicillin-susceptible S. aureus (MSSA) bacteremia] had congenital and valvular heart diseases (18% vs 0%, p=0.004), an initial presentation of acute respiratory failure (32% vs 11%, p=0.022), an implant as a portal of entry (9% vs 0%, p=0.014), and mortality (41% vs 20%, p=0.05). Acute Physiology and Chronic Health Evaluation (APACHE) III score was significantly higher in patients who died than in patients who survived in both the MRSA and MSSA bacteremia groups. Inappropriate treatment was more frequent in patients with MRSA bacteremia than in MSSA bacteremia. When a Gram-positive coccemia is initially noted in a patient with high APACHE III score and/or acute respiratory failure, early and aggressive treatment including glycopeptide should be considered.

Adult↗
PubMed2004

Resistance rates to commonly used antimicrobials among pathogens of both bacteremic and non-bacteremic community-acquired urinary tract infection.

This study examined the distribution of organisms and their antimicrobial resistance in patients admitted due to acute bacteremic and non-bacteremic community-acquired urinary tract infection (UTI). During a period of 1 year and 1 month, a total of 201 patients and 253 bacterial isolates were studied. Fever higher than 38.5 degrees C was significantly more common in the bacteremic group than the non-bacteremic group (68% vs 48%; p<0.05). Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, and Proteus mirabilis were the most common organisms isolated. E. coli was the leading pathogen and it was significantly more predominant in bacteremic UTI than non-bacteremic UTI (73% vs 49%; p<0.01). Bacteria other than E. coli (i.e., K. pneumoniae, P. aeruginosa, Proteus spp., Morganella morganii, Enterobacter cloacae, Citrobacter spp., Acinetobacter baumannii, Serratia marcescens, and Providencia spp.) were more common in non-bacteremic UTI than bacteremic UTI (44% vs 22%; p<0.01). E. coli isolated from both bacteremic and non-bacteremic patients had a high rate of resistance to ampicillin (80%), cephalothin (59%), gentamicin (29%), piperacillin (61%), trimethoprim-sulfamethoxazole (56%), amoxicillin-clavulanic acid (34%), and ticarcillin-clavulanic acid (36%). Isolates of P. aeruginosa, K. pneumoniae, and Proteus spp. from the non-bacteremic group showed a higher proportion of resistance to extended-spectrum cephalosporins, aminoglycosides (netilmicin and amikacin) and ciprofloxacin. The emergence of a high rate of resistance to commonly used antimicrobials (ampicillin, cephalothin, gentamicin, trimethoprim-sulfamethoxazole, piperacillin, amoxicillin-clavulanic acid and ticarcillin-clavulanic acid) may have an impact on the antibiotic treatment of patients admitted due to acute community-acquired bacteremic or non-bacteremic UTI in Taiwan. Further studies are needed to clarify the impact of antimicrobial resistance on the outcome in these conditions.

Adult↗
PubMed2004

Community-acquired brain abscess in Taiwan: etiology and probable source of infection.

Brain abscess is a life-threatening infection caused by spread from infected parameningeal or remote foci. Historically, streptococci have been the predominant organisms reported while brain abscess metastatic from liver abscess caused by Klebsiella pneumoniae has been a more recent emerging problem. This study retrospectively analyzed the characteristics of community-acquired brain abscess admitted during an 11-year period. There were 17 men and 7 women with age from 20 to 82 years (median, 41 years). The most common source of infection was liver abscess, followed by otitic infection and sinusitis. The classic triad of fever, headache and focal neurologic deficit was noted in only 25% of cases. Spread of the abscess to multiple lobes was common (n = 6). The most commonly identified organisms were Streptococcus spp. (n = 7) and K. pneumoniae (n = 5). All 5 cases of K. pneumoniae brain abscess also had concomitant pyogenic liver abscess and 4 of them had diabetes mellitus. In this study, brain abscess was common in young patients and in patients with diabetes mellitus. In Taiwan, Streptococcus spp. and K. pneumoniae are leading etiologies for community-acquired brain abscess. Liver abscess is the most likely source of K. pneumoniae brain abscess.

Adolescent↗
PubMed2003

Staphylococcus aureus bacteremia: recurrence and the impact of antibiotic treatment in a prospective multicenter study.

Staphylococcus aureus bacteremia is associated with substantial morbidity. Recurrence is common, but incidence and risk factors for recurrence are uncertain. The emergence of methicillin resistance and the ease of administering vancomycin, especially in patients who have renal insufficiency, have led to reliance on this drug with the assumption that it is as effective as beta-lactam antibiotics, an assumption that remains open to debate. We initiated a multicenter, prospective observational study in 6 university hospitals and enrolled 505 consecutive patients with S. aureus bacteremia. All patients were monitored for 6 months and patients with endocarditis were followed for 3 years. Recurrence was defined as return of S. aureus bacteremia after documentation of negative blood cultures and/or clinical improvement after completing a course of antistaphylococcal antibiotic therapy. All blood isolates taken from patients with recurrent bacteremia underwent pulsed-field gel electrophoresis testing. Recurrence was subclassified as reinfection (different pulsed-field gel electrophoresis patterns) or relapse (same pulsed-field gel electrophoresis pattern).Forty-two patients experienced 56 episodes of recurrence (79% were relapses and 21% were reinfection). Relapse occurred earlier than reinfection (median, 36 versus 99 d, p < 0.06). Risk factors for relapse of S. aureus bacteremia included valvular heart disease, cirrhosis of the liver, and deep-seated infection (including endocarditis). Nafcillin was superior to vancomycin in preventing bacteriologic failure (persistent bacteremia or relapse) for methicillin-susceptible S. aureus (MSSA) bacteremia. Failure to remove infected intravascular devices/catheters and vancomycin therapy were common factors in patients experiencing multiple (greater than 2) relapses. However, by multivariate analysis, only endocarditis and therapy with vancomycin (versus nafcillin) were significantly associated with relapse. Recurrences occurred in 9.4% of S. aureus bacteremias following antistaphylococcal therapy, and most were relapses. Duration of antistaphylococcal therapy was not associated with relapse, but type of antibiotic therapy was. Nafcillin was superior to vancomycin in efficacy in patients with MSSA bacteremia.

Adolescent↗
PubMed2003

A prospective multicenter study of Staphylococcus aureus bacteremia: incidence of endocarditis, risk factors for mortality, and clinical impact of methicillin resistance.

Our objectives were to determine the incidence of endocarditis in patients whose Staphylococcus aureus bacteremia was community-acquired, related to hemodialysis, or hospital-acquired; to assess clinical factors that would reliably distinguished between S. aureus bacteremia and S. aureus endocarditis; to assess the emergence of methicillin-resistant S. aureus (MRSA) as a cause of endocarditis; and to examine risk factors for mortality in patients with S. aureus endocarditis. We conducted a prospective observational study in 6 university teaching hospitals; we evaluated 505 consecutive patients with Staphylococcus aureus bacteremia. Thirteen percent of patients with S. aureus bacteremia were found to have endocarditis, including 21% with community-acquired S. aureus bacteremia, 5% with hospital-acquired bacteremia, and 12% on hemodialysis. Infection was due to MRSA in 31%. Factors predictive of endocarditis included underlying valvular heart disease, history of prior endocarditis, intravenous drug use, community acquisition of bacteremia, and an unrecognized source. Twelve patients with bacteremia had a prosthetic valve; 17% developed endocarditis. Unexpectedly, nonwhite race proved to be an independent risk factor for endocarditis by both univariate and multivariate analyses. Persistent bacteremia (positive blood cultures at day 3 of appropriate therapy) was identified as an independent risk factor for both endocarditis and mortality, a unique observation not reported in other prospective studies of S. aureus bacteremia. Patients with endocarditis due to MRSA were significantly more likely to have complicating renal insufficiency and to experience persistent bacteremia than those with endocarditis due to MSSA. The 30-day mortality was 31% among patients with endocarditis compared to 21% in patients who had bacteremia without endocarditis (p = 0.055). Risk factors for death due to endocarditis included severity of illness at onset of bacteremia (as measured by Apache III and Pitt bacteremia score), MRSA infection, and presence of atrioventricular block on electrocardiogram. Patients with S. aureus bacteremia who have community acquisition of infection, underlying valvular heart disease, intravenous drug use, unknown portal of entry, history of prior endocarditis, and possibly, nonwhite race should undergo echocardiography to screen for the presence of endocarditis. We recommend that blood cultures be repeated 3 days following initiation of antistaphylococcal antibiotic therapy in all patients with S. aureus bacteremia. Positive blood cultures at 3 days may prove to be a useful marker in promoting more aggressive management, including more potent antibiotic therapy and surgical resection of the valve in endocarditis cases. MRSA as the infecting organism should be added to the list of risk factors for consideration of valvular resection in cases of endocarditis.

Bacteremia↗
PubMed2003

Extended-spectrum cephalosporin compared to cefazolin for treatment of Klebsiella pneumoniae-caused liver abscess.

From January 1995 to May 2000, a total of 107 adults with liver abscess due to Klebsiella pneumoniae admitted at a large medical center in northern Taiwan were reviewed. Patients were considered to have received cefazolin or an extended-spectrum cephalosporin if they received at least 3 days of that antibiotic within the first 5 days of hospitalization. Fifty-nine (55.1%) patients received cefazolin, and 48 (44.9%) patients received an extended-spectrum cephalosporin. The demographic data, clinical features, severities of illness, and rates of early drainage for the two groups were comparable. However, the rates of developing complications for the two groups were significantly different (37.3 versus 6.3%, respectively; P < 0.001). Furthermore, six independent factors preventing severe complications following liver abscess due to K. pneumoniae were identified: normal platelet count, alkaline phosphatase less than 300 U/liter, no gas formation in the abscess, APACHE III score less than 40, use of an extended-spectrum cephalosporin, and early drainage. In conclusion, cefazolin therapy may be suboptimal for patients with liver abscess due to K. pneumoniae despite active in vitro susceptibility. Use of an extended-spectrum cephalosporin and early drainage for patients with liver abscess due to K. pneumoniae are suggested.

APACHE↗
PubMed2003

Telithromycin- and fluoroquinolone-resistant Streptococcus pneumoniae in Taiwan with high prevalence of resistance to macrolides and beta-lactams: SMART program 2001 data.

There is a high prevalence of beta-lactam- and macrolide-resistant Streptococcus pneumoniae in Taiwan. To understand the in vitro susceptibilities of recent isolates of S. pneumoniae to fluoroquinolones and telithromycin (which is not available in Taiwan), the MICs of 23 antimicrobial agents for 936 clinical isolates of S. pneumoniae isolated from different parts of Taiwan from 2000 to 2001 were determined by the agar dilution method. Overall, 72% of isolates were not susceptible to penicillin (with 61% being intermediate and 11% being resistant) and 92% were resistant to erythromycin. Telithromycin MICs were >or=1 microg/ml for 16% of the isolates, and for 99% of these isolates the MICs of all macrolides tested were >or=256 microg/ml; all of these isolates had the constitutive macrolide-lincosamide-streptogramin B phenotype. Eighty-eight percent of the isolates were resistant to three or more classes of drugs. The ciprofloxacin MICs were >or=4 microg/ml for six (0.6%) isolates from five patients collected in 2000 and 2001, and the levofloxacin MICs were >or=8 microg/ml for five of these isolates. Seven isolates for which ciprofloxacin MICs were >or=4 microg/ml, including one isolate recovered in 1999, belonged to three serotypes (serotype 19F, five isolates; serotype 23A, one isolate; and serotype 23B, one isolate). The isolates from the six patients for which ciprofloxacin MICs were >or=4 microg/ml had different pulsed-field gel electrophoresis profiles and random amplified polymorphic DNA patterns, indicating that no clonal dissemination occurred over this time period. Despite the increased rate of fluoroquinolone use, the proportion of pneumococcal isolates for which ciprofloxacin MICs were elevated (>or=4 microg/ml) remained low. However, the occurrence of telithromycin resistance is impressive and raises concerns for the future.

Adult↗
PubMed2003

Telithromycin and quinupristin-dalfopristin resistance in clinical isolates of Streptococcus pyogenes: SMART Program 2001 Data.

This study evaluated the current status of antimicrobial resistance in clinical isolates of Streptococcus pyogenes in Taiwan as part of the SMART (Surveillance from Multicenter Antimicrobial Resistance in Taiwan) program. In 2001, 419 different isolates of S. pyogenes, including 275 from respiratory secretions, 87 from wound pus, and 31 from blood, were collected from nine hospitals in different parts of Taiwan. MICs of 23 antimicrobial agents were determined at a central location by the agar dilution method. All of the isolates were susceptible to penicillin (MIC at which 90% of the isolates were inhibited [MIC(90)], moxifloxacin > ciprofloxacin = levofloxacin = gatifloxacin > gemifloxacin) demonstrated potent activity against nearly all of the isolates of S. pyogenes tested. Thirty-two isolates (8%) were not susceptible to quinupristin-dalfopristin. Seventeen percent of isolates had telithromycin MICs of >or=1 microg/ml, and all of these isolates exhibited erythromycin MICs of >or=32 microg/ml. The high prevalence of resistance to telithromycin (which is not available in Taiwan) limits its potential use in the treatment of S. pyogenes infections, particularly in areas with high rates of macrolide resistance.

Anti-Bacterial Agents↗
PubMed2003

Acute acalculous cholecystitis and pancreatitis in a patient with concomitant leptospirosis and scrub typhus.

Concomitant leptospirosis and scrub typhus is rare. The spectrum of clinical severity for both scrub typhus and leptospirosis ranges from mild to fatal. Acute pancreatitis and cholecystitis are infrequent complications in adult patients with either leptospirosis or scrub typhus. We report a case of leptospirosis and scrub typhus coinfection in a 41-year-old man presenting with acute acalculous cholecystitis, pancreatitis and acute renal failure. Abdominal computed tomography revealed edematous change of the gallbladder without intrahepatic or pancreatic lesions. The patient was successfully treated with doxycycline and ceftriaxone, and supportive management.

Acalculous Cholecystitis↗
PubMed2002

Characteristics of bacteremia between community-acquired and nosocomial Klebsiella pneumoniae infection: risk factor for mortality and the impact of capsular serotypes as a herald for community-acquired infection.

BACKGROUND: Although several epidemiological surveys of Klebsiella clinical isolates have been performed, few studies have correlated the clinical isolate with disease. OBJECTIVE: To compare the clinical and bacteriological characteristics of Klebsiella pneumoniae bacteremia acquired as community or nosocomial infections. METHODS: We prospectively enrolled 158 consecutively hospitalized patients with K pneumoniae bacteremia. Clinical data were reviewed. Antimicrobial susceptibility testing and capsular serotyping were performed. We used the chi(2) test, the Fisher exact test, or the t test for statistic analysis. RESULTS: Underlying diabetes mellitus was more common in community-acquired than in nosocomial infection (46/94 [49%] vs. 8/64 [12%]; P<.001). On the other hand, neoplastic disease (34/64 [53%] vs. 13/94 [14%]; P<.001) and antibiotic resistance (P<.01) were more frequent in patients with nosocomial compared with community-acquired infections. Klebsiella pneumoniae liver abscesses, which were all community acquired, accounted for the source of 22 (23%) of 94 community-acquired K pneumoniae infections. No attributable source of infection was found for 37 (58%) of the 64 nosocomial infections vs. 15 (16%) of the 94 community-acquired infections. Only 58 isolates (36.7%) could be serotyped; of these, capsular serotypes K1, K2, and K28 accounted for 37 (23.4%), 8 (5.1%), and 6 (3.8%), respectively, of all strains. However, typeable isolates were significantly more common among community-acquired than nosocomial isolates (42/94 [45%] vs. 16/64 [25%]; P =.01), especially for serotype K1 (28/94 [30%] vs. 9/64 [14%]; P =.02). Significant risk factors for mortality included nosocomial infection, lung infection, thrombocytopenia, leukopenia, ceftazidime resistance, inappropriate antimicrobial therapy, and septic shock. CONCLUSIONS: Significant differences were identified between community-acquired and nosocomial K pneumoniae bacteremia. Ceftazidime resistance in nosocomial K pneumoniae bacteremia carried a high risk for mortality, and serotype K1 in K pneumoniae was more prevalent in community-acquired infection, suggesting more virulence.

Bacteremia↗
PubMed2002

CTX-M-14, a plasmid-mediated CTX-M type extended-spectrum beta-lactamase isolated from Escherichia coli.

Four Escherichia coli isolates harboring CTX-M-14, with a single Ala231-->Val substitution compared to CTX-M-9, had three different ribotypes. Cefotaxime resistance was plasmid encoded and conjugatively transferable. Three isolates had the same plasmid restriction enzyme digestion profile, suggesting clonal spread of a resistant plasmid. A high k(cat)/K(m) value for cefotaxime (20.3 microM(-1) s(-1)) but low values for ceftazidime and aztreonam (< 0.02 microM(-1) s(-1)) were observed in hydrolysis assays, indicating resistance to cefotaxime (MIC > or = 64 microg/ml) but susceptibility to ceftazidime (MIC < or = 2 microg/ml).

Amino Acid Substitution↗