Trend in vancomycin susceptibility and correlation with molecular characteristics of methicillin-resistant Staphylococcus aureus causing invasive infections in Taiwan: results from the Tigecycline in vitro Surveillance in Taiwan (TIST) study, 2006-2010.

This study was intended to investigate the trend in vancomycin susceptibility and correlation with molecular characteristics of methicillin-resistant Staphylococcus aureus (MRSA) causing invasive infections. A total of 670 MRSA isolates were collected from patients with invasive infections as part of bacterial collection in the Tigecycline in vitro Surveillance in Taiwan (TIST) from 2006 to 2010. MICs of the isolates to vancomycin were determined using the agar dilution method. Characteristics of staphylococcal cassette chromosome mec (SCCmec), mec-associated hypervariable region (dru), and accessory gene regulator (agr) of the isolates were identified by polymerase chain reaction methods. MRSA isolates with SCCmec types I, II, and III were molecularly defined as hospital-associated MRSA (HA-MRSA), and those with SCCmec types IV, V, and VT were assigned as community-associated MRSA (CA-MRSA). All but 1 MRSA isolates exhibited vancomycin MICs ≤1 mg/L. A declining trend in vancomycin MICs among MRSA isolates was noted, which was associated with the decline in proportion of HA-MRSA. The percentage of CA-MRSA increased from 25.6% in 2006 to 46.0% in 2010. An increase in the geometric mean of vancomycin MICs was found in MRSA with particular molecular types such as SCCmec types II and III, agr groups I and II, and dru10-14. A significant correlation among particular molecular types was found, including SCCmecII-agr group II-dru4, SCCmecIII-agr group I-dru11-14, SCCmecIV-agr group II-dru9, and SCCmecVT-agr group I-dru9 and dru11. There was no vancomycin creep among MRSA isolates, and the declining trend of vancomycin MIC against MRSA was attributed to the increasing prevalence of CA-MRSA over time.

Trends in the antimicrobial susceptibilities and serotypes of Streptococcus pneumoniae: results from the Tigecycline In Vitro Surveillance in Taiwan (TIST) study, 2006-2010.

Isolates of Streptococcus pneumoniae (n = 530) were collected from 20 hospitals in different parts of Taiwan from 2006 to 2010. MICs to 16 antimicrobial agents were determined by broth dilution method and serotypes were identified by latex agglutination. Based on meningitis (non-meningitis) criteria established by the CLSI, 11.7% (63.2%) of all isolates were susceptible to penicillin and 46.0% (83.8%) were susceptible to ceftriaxone. Of the isolates, 94.3% were non-susceptible to azithromycin and 5.8% and 7.2% were non-susceptible to moxifloxacin and levofloxacin, respectively. Susceptibility to penicillin by meningitis criteria increased significantly (P = 0.0012) with year, and that to clindamycin and amoxicillin/clavulanic acid declined significantly (P < 0.05). Six major serotypes were found, namely 19F (24.0%), 23F (18.5%), 14 (13.6%), 6B (12.5%), 19A (7.5%) and 3 (5.1%). Prevalence of serotypes 19F and 14 remained stationary, that of serotype 6B decreased significantly (P < 0.0001) and that of serotype 19A increased significantly (P < 0.0001) with year. The coverage rate of PCV-7 among the pneumococcal isolates declined from 80.5% in 2006 to 50% in 2010 (P < 0.0001) and that of PCV-13 declined from 91.5% in 2009 to 75% in 2010. The non-susceptibility rate to levofloxacin was highest among serotype 23F isolates (13.3%) and lowest among serotype 19A isolates (2.5%). Rates of resistance to the four agents penicillin, ceftriaxone, azithromycin and clindamycin were highest among serotype 19A isolates (70.0%) and 23F isolates (49.0%). All serotype 3 isolates were susceptible to four of the most commonly used antibiotics (penicillin, ceftriaxone, azithromycin and levofloxacin).

Outbreak of Serratia marcescens postsurgical bloodstream infection due to contaminated intravenous pain control fluids.

BACKGROUND: Serratia marcescens is an important nosocomial pathogen causing significant outbreaks. Here we report an outbreak of bloodstream infection caused by S. marcescens at a 3500-bed hospital in Taiwan. The effective cooperative efforts of both laboratory personnel and infection control practitioners (ICPs) jointly contributed to the total control of the outbreak. METHODS: A sudden increase in the isolation of S. marcescens from blood cultures was noted in the Clinical Microbiology Laboratory. The information was passed to the ICPs and an investigation was initiated. Pulsed-field gel electrophoresis was used to study the relationships among the isolates. RESULTS: Pulsotype A was identified in 43 (82.7%) of the 52 blood isolates studied. They were isolated from 52 patients distributed across 22 wards that were surveyed by seven ICPs. All patients had undergone surgery before the infection, and fentanyl-containing intravenous fluids were used for pain control in 43 of them. Isolates from 42 belonged to pulsotype A. Three S. marcescens isolates, all from fentanyl-containing fluids and demonstrating pulsotype A, were identified from 251 environmental cultures. All fentanyl-containing fluids that were in use were withdrawn and the outbreak was stopped. CONCLUSIONS: The outbreak of S. marcescens bloodstream infection apparently occurred through the use of fentanyl-containing fluids contaminated by a pulsotype A S. marcescens.

Trends in susceptibility of vancomycin-resistant Enterococcus faecium to tigecycline, daptomycin, and linezolid and molecular epidemiology of the isolates: results from the Tigecycline In Vitro Surveillance in Taiwan (TIST) study, 2006 to 2010.

Among the 219 vancomycin-resistant Enterococcus faecium isolates collected in 20 Taiwanese hospitals from 2006 to 2010, all were susceptible to linezolid and daptomycin, and 98.6% were susceptible to tigecycline. There was a shift toward higher tigecycline MIC values (MIC(90)s) from 2006-2007 (0.06 µg/ml) to 2008-2010 (0.12 µg/ml). The MIC(90)s of daptomycin and linezolid remained stationary. Although pulsotypes among the isolates from the 20 hospitals varied, intrahospital spreading of several clones was identified in 13 hospitals.

An unusual cause of dyspnea in a patient with cervical herpes zoster.

Motor involvement in acute herpes zoster does occur,but is rare. Most causes of zoster paresis are due to the extension of the inflammation to the anterior horn and/or anterior motor roots. We report a female patient with an unusual diaphragmatic paralysis caused by cervical herpes zoster. The lesion, diagnosed by MRI, involved the anterior horn of the cervical spinal cord.

Agreement assessment of tigecycline susceptibilities determined by the disk diffusion and broth microdilution methods among commonly encountered resistant bacterial isolates: results from the Tigecycline In Vitro Surveillance in Taiwan (TIST) study, 2008 to 2010.

The Tigecycline In Vitro Surveillance in Taiwan (TIST) study, initiated in 2006, is a nationwide surveillance program designed to longitudinally monitor the in vitro activity of tigecycline against commonly encountered drug-resistant bacteria. This study compared the in vitro activity of tigecycline against 3,014 isolates of clinically important drug-resistant bacteria using the standard broth microdilution and disk diffusion methods. Species studied included methicillin-resistant Staphylococcus aureus (MRSA; n = 759), vancomycin-resistant Enterococcus faecium (VRE; n = 191), extended-spectrum ß-lactamase (ESBL)-producing Escherichia coli (n = 602), ESBL-producing Klebsiella pneumoniae (n = 736), and Acinetobacter baumannii (n = 726) that had been collected from patients treated between 2008 and 2010 at 20 hospitals in Taiwan. MICs and inhibition zone diameters were interpreted according to the currently recommended U.S. Food and Drug Administration (FDA) criteria and the European Committee on Antimicrobial Susceptibility Testing (EUCAST) criteria. The MIC(90) values of tigecycline against MRSA, VRE, ESBL-producing E. coli, ESBL-producing K. pneumoniae, and A. baumannii were 0.5, 0.125, 0.5, 2, and 8 µg/ml, respectively. The total error rates between the two methods using the FDA criteria were high: 38.4% for ESBL-producing K. pneumoniae and 33.8% for A. baumannii. Using the EUCAST criteria, the total error rate was also high (54.6%) for A. baumannii isolates. The total error rates between these two methods were <5% for MRSA, VRE, and ESBL-producing E. coli. For routine susceptibility testing of ESBL-producing K. pneumoniae and A. baumannii against tigecycline, the broth microdilution method should be used because of the poor correlation of results between these two methods.

Trends in the susceptibility of clinically important resistant bacteria to tigecycline: results from the Tigecycline In Vitro Surveillance in Taiwan study, 2006 to 2010.

The Tigecycline In Vitro Surveillance in Taiwan (TIST) study, a nationwide, prospective surveillance during 2006 to 2010, collected a total of 7,793 clinical isolates, including methicillin-resistant Staphylococcus aureus (MRSA) (n = 1,834), penicillin-resistant Streptococcus pneumoniae (PRSP) (n = 423), vancomycin-resistant enterococci (VRE) (n = 219), extended-spectrum ß-lactamase (ESBL)-producing Escherichia coli (n = 1,141), ESBL-producing Klebsiella pneumoniae (n = 1,330), Acinetobacter baumannii (n = 1,645), and Stenotrophomonas maltophilia (n = 903), from different specimens from 20 different hospitals in Taiwan. MICs of tigecycline were determined following the criteria of the U.S. Food and Drug Administration (FDA) and the European Committee on Antimicrobial Susceptibility Testing (EUCAST-2011). Among drug-resistant Gram-positive pathogens, all of the PRSP isolates were susceptible to tigecycline (MIC(90), 0.03 µg/ml), and only one MRSA isolate (MIC(90), 0.5 µg/ml) and three VRE isolates (MIC(90), 0.125 µg/ml) were nonsusceptible to tigecycline. Among the Gram-negative bacteria, the tigecycline susceptibility rates were 99.65% for ESBL-producing E. coli (MIC(90), 0.5 µg/ml) and 96.32% for ESBL-producing K. pneumoniae (MIC(90), 2 µg/ml) when interpreted by FDA criteria but were 98.7% and 85.8%, respectively, when interpreted by EUCAST-2011 criteria. The susceptibility rate for A. baumannii (MIC(90), 4 µg/ml) decreased from 80.9% in 2006 to 55.3% in 2009 but increased to 73.4% in 2010. A bimodal MIC distribution was found among carbapenem-susceptible A. baumannii isolates, and a unimodal MIC distribution was found among carbapenem-nonsusceptible A. baumannii isolates. In Taiwan, tigecycline continues to have excellent in vitro activity against several major clinically important drug-resistant bacteria, with the exception of A. baumannii.

The clinical implication and prognostic predictors of tigecycline treatment for pneumonia involving multidrug-resistant Acinetobacter baumannii.

OBJECTIVES: To investigate the clinical implication and prognostic predictors of tigecycline treatment for pneumonia involving multidrug-resistant Acinetobacter baumannii (MDRAB). METHODS: A retrospective observational study over a 32-month period for adult patients receiving tigecycline treatment at least 7 days for pneumonia involving MDRAB. RESULTS: We reviewed 112 patients with 116 episodes of tigecycline-treated pneumonia involving MDRAB. The mean age was 70.8 years. The mean Acute Physiology and Chronic Health Evaluation (APACHE) II score was 21.7. Seventy episodes (60.3%) had clinical resolution. The episodes with monomicrobial MDRAB pneumonia had a significantly lower clinical resolution rate than polymicrobial pneumonia (14/31, 45.2% vs. 56/85, 65.9%; p = 0.044). The independent predictors for failure of clinical resolution were female gender, malignancy, bilateral pneumonia, monomicrobial pneumonia, and higher APHCHE II scores. Forty-two episodes (36.2%) had the 30-day mortality, and the only independent predictor was deterioration of pneumonia on chest radiographs. CONCLUSIONS: A high disease severity, bilateral pneumonia, and monomicrobial MDRAB pneumonia predicted failure of clinical resolution, and deterioration of pneumonia predicted mortality. MDRAB in monomicrobial pneumonia was the most certain to be causal. The clinical resolution rate from such pneumonia might reflect the ultimate efficacy of tigecycline in treating MDRAB pneumonia and the overall efficacy might be overestimated.

Characteristics and outcomes of Fusobacterium nucleatum bacteremia--a 6-year experience at a tertiary care hospital in northern Taiwan.

Fusobacterium nucleatum bacteremia is critical and not well defined. To identify the clinical characteristics and outcomes, we conducted a retrospective review of hospitalized patients from January 2004 to December 2009 at a tertiary center in northern Taiwan. Fifty-seven patients were enrolled. The mean age was 58.1 years, and the mean Pitt bacteremia score was 4.7. Males predominated (59.6%), and the overall 30-day mortality rate was up to 47.4%. Malignancy was the major comorbidity (26/57, 45.6%), especially oropharyngeal and gastrointestinal cancers (19/26, 73.1%). Pneumonia (17/57, 29.8%) was the most common presentation with high rates of respiratory failure (15/17, 88.2%) and mortality (11/17, 64.7%), followed by intra-abdominal infections (7/57, 12.3%). In multivariate analysis, higher Pitt bacteremia score, nosocomial infection, anemia, and intensive care unit stay were the independent factors for 30-day mortality. Nosocomial F. nucleatum bacteremia was a significant mortality predictor independent to other parameters of disease severities.

Residents had an increasing risk of norovirus gastroenteritis infection than health care workers during an outbreak in a nursing home.

OBJECTIVES: To study norovirus gastroenteritis infection among residents and health care workers (HCWs) during an outbreak in a nursing home by investigating the attack rate and positive diagnostic rate for norovirus by reverse transcription-polymerase chain reaction (RT-PCR). METHODS: All members in a Chang Gung Memorial Hospital-affiliated nursing home from November 17, 2006, to November 25, 2006, including 236 residents and 125 HCWs, whose available medical records were available were consecutively included in the retrospective analysis. Fecal specimens of symptomatic residents and HCWs were tested for norovirus by RT-PCR. In addition, routine stool analysis and a stool culture study were conducted to identify the bacterial and parasitic agents. The fecal specimens of asymptomatic residents and HCWs were tested only for norovirus by RT-PCR. RESULTS: The outbreak was controlled within 9 days during the outbreak period. There were 51 symptomatic cases, 41 residents and 10 HCWs, during the norovirus outbreak. The odds ratio (OR) of the attack rate in the residents was approximately 2.4 times higher than that in the HCWs (OR: 2.4; 95% confidence interval [CI]: 1.2-5.0; P = .015). Norovirus was detected in 59 (30.6%) of 193 residents and in 11 (10.5%) of 105 HCWs who provided stool specimens for the study by RT-PCR. The OR of the positive diagnostic rate for norovirus by RT-PCR in the residents was approximately 3.8 times higher than that in the HCWs (OR: 3.8; 95% CI: 1.9-7.5; P < .001). CONCLUSIONS: During an outbreak of norovirus gastroenteritis in a nursing home, the infection can be easily transmitted from person to person and affects both residents and HCWs. In addition, residents had a higher risk of norovirus gastroenteritis infection than HCWs.

Influence of third-generation cephalosporin resistance on adult in-hospital mortality from post-neurosurgical bacterial meningitis.

BACKGROUND/PURPOSE: To investigate the clinical features, etiology and predictors of in-hospital mortality in adults with post-neurosurgical bacterial meningitis. METHODS: This retrospective analysis included 60 adult patients with culture-proven post-neurosurgical bacterial meningitis hospitalized between September 2006 and August 2008. RESULTS: Of the 60 patients, 88.3% had monomicrobial infection and 11.7% had mixed infection. The mean duration from the first neurosurgical procedure to the diagnosis of meningitis was 21 days (range, 1-134 days). The median frequency of neurosurgical procedure before meningitis was 1 (range, 1-5). A total of 69 isolates were identified from the cerebrospinal fluid, the most common pathogens were Gram-negative bacilli (43, 62.3%), followed by Gram-positive bacteria (24, 34.8%). The three most common Gram-negative bacilli were Serratia marcescens (7, 10.1%), Klebsiella pneumoniae (6, 8.7%), and Enterobacter cloacae (4, 5.8%). Pseudomonas aeruginosa and Acinetobacter baumannii isolates comprised less than 3%. Notably, glucose non-fermenting Gram-negative bacilli other than Acinetobacter and Pseudomonas spp. accounted for 11.6% of the total. Of the Gram-negative bacilli, resistance rates to the third-generation cephalosporins, ceftriaxone and ceftazidime, were 58.1% and 34.9%, respectively. The two most common Gram-positive pathogens were Staphylococcus aureus (10, 14.5%) and coagulase-negative staphylococci (including S. epidermidis) (10, 14.5%). The in-hospital mortality rate was 15.0%, which was significantly related to Gram-negative bacilli resistant to third-generation cephalosporins in multivariate analysis (adjusted odds ratio = 33.65; p = 0.047). CONCLUSION: These findings may portend the spread of serious resistance to third-generation cephalosporins in nosocomial Gram-negative bacilli throughout the neurosurgical units, suggestive of the need to reassess the empirical use of third-generation cephalosporins in post-neurosurgical bacterial meningitis.

Syndromic recognition of influenza A infection in a low prevalence community setting.

BACKGROUND: With epidemics of influenza A virus infection, people and medical professionals are all concerned about symptoms or syndromes that may indicate the infection with influenza A virus. METHODOLOGY/PRINCIPAL FINDINGS: A prospective study was performed at a community clinic of a metropolitan area. Throat swab was sampled for 3-6 consecutive adult patients with new episode (<3 days) of respiratory tract infection every weekday from Dec. 8, 2005 to Mar. 31, 2006. Demographic data, relevant history, symptoms and signs were recorded. Samples were processed with multiplex real time PCR for 9 common respiratory tract pathogens and by virus culture. Throat swab samples were positive for Influenza A virus with multiplex real time PCR system in 12 of 240 patients. The 12 influenza A positive cases were with more clusters and chills than the other 228. Certain symptoms and syndromes increased the likelihood of influenza A virus infection. The syndrome of high fever plus chills plus cough, better with clustering of cases in household or workplace, is with the highest likelihood (positive likelihood ratio 95; 95% CI 12-750). Absence of both cluster and chills provides moderate evidence against the infection (negative likelihood ratio 0.51; 95% CI 0.29-0.90). CONCLUSIONS/SIGNIFICANCE: Syndromic recognition is not diagnostic but is useful for discriminating between influenza A infection and common cold. In addition to relevant travel history, confirmatory molecular test can be applied to subjects with high likelihood when the disease prevalence is low.

Prognostic factors of tuberculous meningitis in adults: a 6-year retrospective study at a tertiary hospital in northern Taiwan.

BACKGROUND/PURPOSE: To investigate the clinical features, laboratory test results, imaging data, and prognostic predictors of tuberculous meningitis (TBM) in adults. METHODS: We retrospectively reviewed 108 adult patients with a diagnosis of TBM over a 6-year period. Patients were divided into "definite" and "probable" groups, depending on the diagnosis made by (1) positive culture, or polymerase chain reaction, of Mycobacterium tuberculosis (TB) from the cerebrospinal fluid (CSF); or (2) the isolation of TB elsewhere, or chest radiography consistent with active pulmonary TB, or imaging studies of the brain consistent with TBM, or clinical improvement on treatment. These two groups were compared for their clinical features, images, laboratory test results, and 9-month mortality rates to identify prognostic predictors. RESULTS: Compared with the "probable" group (n = 62), the "definite" group (n = 46) had a higher mortality rate (50.0%vs. 30.6%, p = 0.041) and more consciousness disturbance (78.3%vs. 51.6%, p = 0.005), hydrocephalus (63.4%vs. 40.7%, p= 0.029) and isolation of TB from extra-CSF specimens (41.3%vs. 22.6%, p = 0.037). Old age (p = 0.002), consciousness change (p = 0.032), and hydrocephalus (p = 0.047) were poor prognostic indicators in the "definite" group as assessed by univariate analysis. Severity of TBM at admission and delayed anti-TB therapy resulted in a poor prognosis for all patients. Multiple logistic regression analysis showed that old age and hydrocephalus were independent factors for mortality. Adjunctive steroid therapy over 2 weeks improved survival in both the "definite" (p = 0.002) and "probable" (p = 0.035) groups, but more than 4 weeks of use had no significant effect on mortality. Steroid treatment, therefore, may improve the outcome of patients with TBM. CONCLUSION: Old age, advanced stage of TBM at admission, hydrocephalus, and positive TB culture or polymerase chain reaction of CSF are factors associated with a poor prognosis for TBM. Early diagnosis and treatment, including short term steroid use, are mandatory for clinical care of adult patients with TBM.

Multidrug resistant Acinetobacter baumannii: risk factors for appearance of imipenem resistant strains on patients formerly with susceptible strains.

BACKGROUND: Multidrug resistant Acinetobacter baumannii (MDRAB) is an important nosocomial pathogen usually susceptible to carbapenems; however, growing number of imipenem resistant MDRAB (IR-MDRAB) poses further clinical challenge. The study was designed to identify the risk factors for appearance of IR-MDRAB on patients formerly with imipenem susceptible MDRAB (IS-MDRAB) and the impact on clinical outcomes. METHODOLOGY/PRINCIPAL FINDINGS: A retrospective case control study was carried out for 209 consecutive episodes of IS-MDRAB infection or colonization from August 2001 to March 2005. Forty-nine (23.4%) episodes with succeeding clinical isolates of IR-MDRAB were defined as the cases and 160 (76.6%) with all subsequent clinical isolates of IS-MDRAB were defined as the controls. Quantified antimicrobial selective pressure, "time at risk", severity of illness, comorbidity, and demographic data were incorporated for multivariate analysis, which revealed imipenem or meropenem as the only significant independent risk factor for the appearance of IR-MDRAB (adjusted OR, 1.18; 95% CI, 1.09 to 1.27). With selected cases and controls matched to exclude exogenous source of IR-MDRAB, multivariate analysis still identified carbapenem as the only independent risk factor (adjusted OR, 1.48; 95% CI, 1.14 to 1.92). Case patients had a higher crude mortality rate compared to control patients (57.1% vs. 31.3%, p = 0.001), and the mortality of case patients was associated with shorter duration of "time at risk", i.e., faster appearance of IR-MDRAB (adjusted OR, 0.9; 95% CI, 0.83 to 0.98). CONCLUSIONS/SIGNIFICANCE: Judicious use of carbapenem with deployment of antibiotics stewardship measures is critical for reducing IR-MDRAB and the associated unfavorable outcome.

Clinical significance of and outcomes for Bacteroides fragilis bacteremia.

BACKGROUND AND PURPOSE: Bacteroides fragilis is a virulent anaerobic pathogen, resulting in considerable mortality. This study was conducted to investigate the clinical characteristics, significance of polymicrobial bacteremia, and treatment outcomes of B. fragilis bacteremia. METHODS: This retrospective analysis enrolled 199 adult patients with B. fragilis bacteremia, who were admitted to hospital between January 2004 and May 2007. Chi-squared and Fisher's exact tests were used for comparison. A p value of <0.05 was considered statistically significant. RESULTS: 142 patients with B. fragilis bacteremia (71.4%) had at least 1 underlying disease. Malignancy was the commonest comorbidity (n = 62; 31.2%). Intra-abdominal infection accounted for 49.3% of the infection sources. Seventy seven patients (38.7%) had polymicrobial bacteremia and Escherichia coli was the most common concurrent isolate (n = 24). There was no significant difference in septic shock incidence and clinical outcome between the monomicrobial and polymicrobial groups. The overall 30-day crude mortality rate was 30.7%. Inappropriate early antimicrobial therapy did not affect outcome, but a higher mortality rate was noted for patients who never received appropriate antimicrobial therapy (55.2% vs 26.5%; p = 0.002). Independent risk factors for mortality were age 65 years and older (p = 0.010), malignancy (p = 0.001), shock (p < 0.001), thrombocytopenia (p = 0.026), and lack of surgical intervention (p = 0.035). CONCLUSIONS: B. fragilis bacteremia causes a high mortality rate, especially for elderly people and patients with cancer. Clinicians should be alert to the infectious focus, and appropriate surgical intervention may be necessary to improve outcomes.

Clinical manifestations, antibiotic susceptibility and molecular analysis of Mycobacterium kansasii isolates from a university hospital in Taiwan.

OBJECTIVES: Mycobacterium kansasii causes a variety of infections. Although previous reports on the prognosis of antimicrobial therapy have been mostly satisfactory, problems involving treatment failure or relapse have been encountered. The purpose of this study was to establish a relationship between the clinical treatment outcomes of M. kansasii infections and bacterial drug susceptibility, and their clonality. METHODS: A total of 37 M. kansasii clinical isolates and clinical information on 34 patients were retrospectively collected in a tertiary medical centre in Taiwan. Bacterial drug susceptibility was determined by the microdilution method. The phylogenetic relationship was analysed by PFGE analysis. RESULTS: Results of PFGE typing revealed a major cluster (cluster I) and eight other divergent patterns. Two/three strains leading to treatment failure were also multidrug resistant and belonged to cluster I. CONCLUSIONS: A relationship between high drug resistance and genetic relatedness of some M. kansasii strains was established. This was associated with clinical treatment failure.

Nationwide surveillance in Taiwan of the in-vitro activity of tigecycline against clinical isolates of extended-spectrum beta-lactamase-producing Enterobacteriaceae.

Tigecycline In-vitro Surveillance in Taiwan (TIST), initiated in 2006, is a nationwide surveillance programme designed to monitor longitudinally the in-vitro activity of tigecycline against commonly encountered resistant bacteria. This study compared the in-vitro activity of tigecycline against clinical isolates of resistant Gram-negative bacteria determined by the broth microdilution and Etest methods. A total of 622 isolates were collected from patients treated at 20 teaching hospitals. Tigecycline had excellent in-vitro activity against extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli (N = 275) with MIC(90) 0.5 microg/mL and a 99.6% susceptibility rate, and also against ESBL-producing Klebsiella pneumoniae (N = 324) with MIC(90) 2 microg/mL and a 98.5% susceptibility rate. For ESBL-producing Proteus mirabilis (N = 15) the MIC(90) was 4 microg/mL with a 73.3% susceptibility rate. For ESBL-producing Klebsiella oxytoca (N = 8) the MIC(50) and MIC(90) were 0.5 and 1 microg/mL, respectively, with a 100% susceptibility rate. Limited agreement (<80%) was found between the broth microdilution and the Etest methods when determining the in-vitro activity of tigecycline against ESBL- producing K. pneumoniae and K. oxytoca.

In-vitro activity of tigecycline against clinical isolates of Acinetobacter baumannii in Taiwan.

We performed susceptibility testing using the microdilution method to determine the in-vitro activity of tigecycline against 393 Acinetobacter baumannii clinical isolates collected in 2006 from 19 hospitals in Taiwan. Significant proportions of the isolates were resistant to imipenem (44%), ciprofloxacin (75%), amikacin (69%), sulbactam (34%) and all four antibiotics (22%), and susceptibility to tigecycline among these different resistant phenotypes of A. baumannii varied from 71% to 82%. The minimum inhibitory concentration (MIC) of tigecycline ranged from 0.6 to 16 microg/mL (MIC(50) 2 microg/mL; MIC(90) 4 microg/mL). The cumulative curve of tigecycline MICs showed that when the MIC cut-offs were set at 2 microg/mL and 4 microg/mL, 80.9% and 93.1% of the isolates were susceptible, respectively. As tigecycline will be used in the future for infections caused by multidrug-resistant A. baumannii because of limited antibiotic choice, and as resistance to tigecycline in A. baumannii isolates may develop following antibiotic exposure, continuous monitoring of the susceptibility of A. baumannii isolates to tigecycline is warranted.

In-vitro activity of tigecycline against clinical isolates of Acinetobacter baumannii in Taiwan determined by the broth microdilution and disk diffusion methods.

A total of 393 isolates of A. baumannii were collected from patients treated at 19 teaching hospitals in Taiwan. Minimum inhibitory concentrations (MICs) and inhibitory zone diameters for tigecycline were determined by the broth microdilution method and the disk diffusion method, respectively. The MIC results were interpreted using the US FDA tigecycline susceptibility breakpoints for Enterobacteriaceae (susceptible [S] or=8 microg/mL). The disk diffusion results were interpreted by criteria recommended by Jones et al. (S >or=16 mm; I 13-15 mm; R or=19 mm; I 15-18 mm; R

A correlation between the severity of lung lesions on radiographs and clinical findings in patients with severe acute respiratory syndrome.

OBJECTIVE: The purpose of this study was to quantify lesions on chest radiographs in patients with severe acute respiratory syndrome (SARS) and analyze the severity of the lesions with clinical parameters. MATERIALS AND METHODS: Two experienced radiologists reviewed chest radiographs of 28 patients with SARS. Each lung was divided into upper, middle, and lower zones. A SARS-related lesion in each zone was scored using a four-point scale: zero to three. The mean and maximal radiographic scores were analyzed statistically to determine if the scorings were related to the laboratory data and clinical course. RESULTS: Forward stepwise multiple linear regression showed that the mean radiographic score correlated most significantly with the number of hospitalized days (p < 0.001). The second most significant factor was the absolute lymphocyte count (p < 0.001) and the third most significant factor was the number of days of intubation (p = 0.025). The maximal radiographic score correlated best with the percentage of lymphocytes in a leukocyte count (p < 0.001), while the second most significant factor was the number of hospitalized days (p < 0.001) and the third most significant factor was the absolute lymphocyte count (p = 0.013). The mean radiographic scores of the patients who died, with comorbidities and without a comorbidity were 11.1, 6.3 and 2.9, respectively (p = 0.032). The corresponding value for maximal radiographic scores were 17.7, 9.7 and 6.0, respectively (p = 0.033). CONCLUSION: The severity of abnormalities quantified on chest radiographs in patients with SARS correlates with the clinical parameters.