Clinical and microbiological characteristics of Klebsiella pneumoniae from community-acquired recurrent urinary tract infections

Understanding the pathogenesis of recurrent urinary tract infection (RUTI) and whether it is attributable to reinfection with a new strain or relapse with the primary infecting strain is of considerable importance. Because previous studies regarding community-acquired Klebsiella pneumoniae RUTI are inconclusive, we undertook this study to evaluate the characteristics of the host and the bacterial agent K. pneumoniae in RUTI. A prospective study was designed, using consecutive patients diagnosed with community-acquired K. pneumoniae-related UTI from January 2007 to December 2009. Of the total 468 consecutive episodes, we found 7 patients with RUTI. All the patients with RUTI were elderly (median, 74 years), with diabetes (100 %, 7 out of 7). Clinical K. pneumoniae isolates derived from the same patients with RUTI revealed identical genomic fingerprints, indicating that K. pneumoniae UTI relapsed despite appropriate antibiotic therapy. The antimicrobial resistance, growth curve and biofilm formation of the recurrent isolates did not change. K. pneumoniae strains causing RUTI had more adhesion and invasiveness than the colonization strains (p?p?=?0.03) in the RUTI group. Our data suggest that K. pneumoniae strains might be able to persist within the urinary tract despite appropriate antibiotic treatment, and the greater adhesion and invasiveness in the recurrent strains may play an important role in recurrent infections.     

Clinical and microbiological characteristics of community-acquired Staphylococcus lugdunensis infections in Southern Taiwan

Most Staphylococcus lugdunensis strains (49/59, 83%) were related to clinical infections, were susceptible to most antimicrobial agents with an overall oxacillin-resistant rate of 5% (3/58), and carried relatively great genetic diversity. Community-acquired infections (41/49, 84%) were dominant, often developed in patients with comorbidity, and had rather benign clinical courses without mortality.     

Complicated parapneumonic effusion and empyema in children.

BACKGROUND AND PURPOSE: Parapneumonic effusion and empyema are recognized complications of bacterial pneumonia. Optimal management in children, especially the duration of parenteral antibiotics and the role of surgery, is controversial. This study analyzed the clinical characteristics, management, outcome, and bacterial etiology of 59 patients with complicated parapneumonic effusion and empyema treated at a single medical center in Kaohsiung from January 1995 to March 2004. METHODS: The diagnosis of complicated parapneumonic effusion was based on the specific characteristics of pleural fluid, computed tomography or ultrasound findings, or direct visualization of loculations during the surgical procedure. RESULTS: Causative agents were culture-confirmed in 42% of the cases. Streptococcus pneumoniae was the leading pathogen in this series (20% of cases). None of the S. pneumoniae isolates were susceptible to penicillin. Mycoplasma pneumoniae accounted for 19% of cases based on immunoglobulin M assay. CONCLUSIONS: An initial combination therapy regimen consisting of cefotaxime or ceftriaxone plus macrolide provided reasonable activity against 80% of the pathogens isolated in this series. This study also revealed that prolonged parenteral antibiotic treatment resulted in longer length of hospital stay.     

Clinical spectrum and molecular characteristics of Klebsiella pneumoniae causing community-acquired extrahepatic abscess

BACKGROUND AND PURPOSE: Klebsiella pneumoniae causes a wide spectrum of infections, including abscess and non-abscess formation. This study investigated the clinical spectrum and molecular characteristics of community-acquired Klebsiella infection with primary extrahepatic abscess. METHODS: From April 2004 through March 2007, a total of 18 strains of K. pneumoniae, 11 from blood and 7 from focal purulent specimens, were recovered from a medical center in southern Taiwan. The clinical data were collected from medical records. Hypermucoviscosity phenotype was defined as positive string test. The virulence genes, including rmpA (regulator of mucoid phenotype), magA (specific to K1 capsule serotype), k(2)A (specific to K2 capsule serotype), and kfu (an iron uptake system) were amplified by polymerase chain reaction using specific primers. RESULTS: Twelve men and 6 women with ages ranging from 37 to 74 years were enrolled. Fifteen patients had underlying diabetes mellitus. The duration of hospitalization ranged from 1 to 96 days. Three patients died by the end of treatment. All of the K. pneumoniae strains carried rmpA and 16 strains showed the hypermucoviscosity phenotype. Of the 18 strains, 7 strains were positive for k(2)A and 4 strains carried magA. kfu was identified in 4 magA-positive strains and 2 magA-negative/k(2)A-negative strains. CONCLUSION: Diabetes mellitus was the most frequent underlying disease among our patients. The rmpA and/or hypermucoviscosity phenotype were the most common virulence factors in K. pneumoniae isolates causing extrahepatic abscesses, among which K2 capsule serotype (k(2)A(+)) was more prevalent than K1 capsule serotype (magA(+)).     

Liver abscess caused by Klebsiella pneumoniae in siblings

Klebsiella pneumoniae has been emerging as the leading cause of liver abscess in diabetic patients. Results of molecular typing of K. pneumoniae isolates from two siblings with liver abscess, their family members, and the environment suggest a possibility of cross infection of liver abscess by the fecal-oral route within diabetic patients.     

Rapidly fatal community-acquired pneumonia due to Klebsiella pneumoniae complicated with acute myocarditis and accelerated idioventricular rhythm

We describe a previously healthy 52-year-old man with rapidly fatal community-acquired pneumonia caused by Klebsiella pneumoniae. The patient developed acute renal dysfunction, accelerated idioventricular rhythm (acute myocarditis), lactic acidosis and septic shock. He died within 15 hours after admission despite intravenous levofloxacin (750 mg daily) and aggressive medical treatment.     

Comparison of pyogenic liver abscess caused by non-Klebsiella pneumoniae and Klebsiella pneumoniae.

From January 1996 to April 2002, a total of 248 patients with pyogenic liver abscess were enrolled in this study. Abscesses caused by Klebsiella pneumoniae accounted for 69% (171) of cases. Abscesses caused by K. pneumoniae were more strongly associated with diabetes mellitus or impaired fasting glucose than liver abscesses caused by non-K. pneumoniae (70.2% vs 32.5%). Solitary abscess and monomicrobial isolates were more frequent in the K. pneumoniae group than that in the non-K. pneumoniae group. A total of 42 patients were treated with antibiotics alone. Antibiotics treatment was combined with other procedures, including single aspiration in 23 patients, percutaneous drainage in 176 and surgical drainage in 7. A higher incidence of metastatic infections occurred in the K. pneumoniae group than in the non-K. pneumoniae group (14.6% vs 3.8%). By contrast, the mortality rate of the K. pneumoniae group was lower than that of non-K. pneumoniae group (4.1% vs 20.8%). There was no significant difference in the relapse rate between these 2 groups (6.5% vs 6.4%). We also found that the presence of respiratory symptoms (including cough, dyspnea, or chest distress), size of abscess > or =5 cm in diameter and non-K. pneumoniae pathogens were significant prognostic factors for mortality.     

Clinical and microbiological characteristics of infections caused by various Nocardia species in Taiwan: a multicenter study from 1998 to 2010

This multicenter study in Taiwan investigated the clinical presentations of various Nocardia species infections based on 16S rRNA sequence analysis. Patients with nocardiosis in four large medical centers from 1998 to 2010 were included. A total of 100 preserved nonduplicate isolates causing human infection were identified as Nocardia species. Sequencing analysis of 16S rRNA confirmed that 35 of 36 N. asteroides isolates identified by conventional tests were non-asteroides Nocardia species, and that two of 50 N. brasiliensis isolates had also been initially misidentified. N. brasiliensis (50%) was the most common pathogen, followed by N. cyriacigeorgica (18%). In addition, several rare pathogens were identified, including N. asiatica, N. rhamnosiphila, N. abscessus, N. transvalensis, N. elegans, and N. carnea. Primary cutaneous infection was the most common presentation, noted in 55 (55%) patients, while pulmonary infection presented in 26 (26%) patients. The crude mortality rate was 6.7% (6/89), and was lowest for primary cutaneous infection (2.2%) and highest for disseminated disease and pulmonary infection (16.7%). In conclusion, N. brasiliensis and N. cyriacigeorgica were the most common pathogens causing nocardiosis in Taiwan. Molecular methods for identifying Nocardia to the species level are mandatory for better understanding the epidemiology and clinical characteristics of patients with nocardiosis.     

Liver abscess caused by magA+ Klebsiella pneumoniae in North America

Taiwan has witnessed an emerging syndrome of liver abscess caused by Klebsiella pneumoniae carrying the magA gene required for exopolysaccharide web biosynthesis. We report a patient transferred from Alaska to Washington State with a magA(+) K. pneumoniae liver abscess and describe a simple approach for recognition of these hypervirulent strains.     

Invasive pneumococcal disease caused by ceftriaxone-resistant Streptococcus pneumoniae in Taiwan

Background

Invasive pneumococcal disease (IPD) was associated with mortality, but the risk factors associated with mortality remains controversial.

Incidence of community-acquired pneumonia caused byChlamydia pneumoniae in Italian patients

The incidence ofChlamydia pneumoniae as a cause of community-acquired pneumonia was evaluated in a one-year prospective study in 108 patients with community-acquired pneumonia. The bacteriological diagnosis was based on culture of sputum or bronchial aspirate and examination of acute and convalescent phase sera forMycoplasma pneumoniae, Legionella pneumophila andChlamydia pneumoniae. A definitive microbiological diagnosis was obtained in 58 (54 %) patients.Chlamydia pneumoniae was the causative agent in 14 patients (13 %) on the basis of positive serological tests; in 10 of the 14 patientsChlamydia pneumoniae was also detected by means of an indirect immunofluorescence test using pharyngeal swab specimens. In conclusion,Chlamydia pneumoniae seems to be a common etiological agent of community-acquired pneumonia, as increasingly reported in the last six to seven years.     

Clinical and microbiological characteristics of mycotic aneurysms in a medical center in southern Taiwan

BACKGROUND AND PURPOSE: Mycotic aneurysm poses a high risk of mortality. This study evaluated the demographic and clinical characteristics and outcomes of hospitalized patients with mycotic aneurysm. METHODS: Patients with mycotic aneurysm hospitalized between March 1996 and May 2006 at a medical center in southern Taiwan were retrospectively analyzed. RESULTS: Fifty two patients (38 men and 14 women; mean age, 64.5 +/- 15.6 years) were included. The leading underlying diseases were diabetes mellitus (40.4%), hypertension (21.2%), and renal disease and heart disease (19.2% each). The most common pathogens isolated from blood and/or resected tissue were Salmonella spp. (34.6%), Klebsiella pneumoniae (11.5%) and Staphylococcus aureus (11.5%). Mycotic aneurysms caused by Gram-negative bacilli were significantly more likely to occur in older patients (p=0.018) and at infrarenal sites (p=0.021). There were trends suggesting that mycotic aneurysms were more likely to be caused by Gram-negative bacilli in patients receiving steroid treatment and in those with underlying diabetes mellitus. Mycotic aneurysms caused by Gram-positive cocci were significantly more likely to occur in suprarenal arteries (p=0.048), especially intracranially (p=0.002), in younger patients (p=0.018) and in patients with concurrent endocarditis (p=0.008). The overall in-hospital mortality rate was 30.6%, and there was no significant difference in in-hospital mortality between mycotic aneurysms caused by Gram-negative bacilli and those due to Gram-positive cocci. CONCLUSIONS: The relationship between the anatomic site of mycotic aneurysm and the spectrum of culprit bacteria may help clinicians promptly choose appropriate antibiotic regimens on an empirical basis. Further study is required to understand better the role of K. pneumoniae in mycotic aneurysm in Taiwan.     

Klebsiella pneumoniae strains producing extended-spectrum beta-lactamases in Spain: microbiological and clinical features

Extended-spectrum β-lactamases (ESBL) of the CTX-M, SHV, and TEM families were recognized in 76 (67%), 31 (27%), and 6 (5%) isolates, respectively, among 162 ESBL-producing Klebsiella pneumoniae (ESBL-Kp) strains obtained in a multicenter study in Spain. Predisposing factors for ESBL-Kp acquisition included invasive procedures, mechanical ventilation, and previous antimicrobial use.     

Clinical and microbiological characteristics of bacteremia caused by Eggerthella, Paraeggerthella, and Eubacterium species at a university hospital in Taiwan from 2001 to 2010

We describe 16 patients with bacteremia caused by Eggerthella lenta (n = 7), Paraeggerthella hongkongensis (n = 3), Eubacterium limosum (n = 4), Eubacterium callanderi (n = 1), and concomitant Eubacterium limosum/Eggerthella lenta (n = 1). Nine (56%) patients had polymicrobial bacteremia. The overall 60-day mortality rate was 19%, and all deaths occurred in patients with E. lenta bacteremia.     

Clinical and microbiological epidemiology of Streptococcus pneumoniae bacteraemia

A survey of Streptococcus pneumoniae bacteraemia in the Grampian region of Scotland was carried out over a 2-year period. One hundred and four bacteraemic episodes were identified in 103 patients, an incidence of 9.8/100,000 population/year, and the mortality was 24%. Clinical information was abstracted from 92 sets of patient notes and 98 isolates of S. pneumoniae were available for further study. The incidence of S. pneumoniae bacteraemia was highest at the extremes of age and peaked at 78 cases/100,000 population/year in those over 80 years old. Many patients had predisposing conditions, of which chronic lung disease (23%), chronic alcohol abuse (10%) and malignant disease (10%) were the commonest. Age was the highest risk factor for mortality, with 20 of the 22 deaths in those over 65 years old. The commonest serotype of S. pneumoniae isolated was serotype 14 (23.5%). Only one isolate (serotype 6A) showed intermediate resistance to penicillin, but 12 isolates (12.2%) were resistant to erythromycin. Nine of these 12 isolates were of serotype 14 and had MICs clustered in the range 12-24 mg/L. Examination of all serotype 14 isolates by pulsed-field gel electrophoresis (PFGE) showed the presence of two distinct genetic clusters, with all the erythromycin-resistant isolates in the same cluster. These isolates had similar PFGE profiles to erythromycin-resistant serotype 14 strains isolated elsewhere in the UK and they were positive for the mefE gene by PCR, confirming that resistance was of the M phenotype. The recent increase in erythromycin resistance in S. pneumoniae may be due, at least in part, to the spread of a serotype 14 clone of the M phenotype which appears to be an important cause of invasive disease.     

Septic pulmonary embolism caused by a Klebsiella pneumoniae liver abscess: clinical characteristics,imaging findings,and clinical courses

OBJECTIVES:

Septic pulmonary embolism caused by a Klebsiella (K.) pneumoniae liver abscess is rare but can cause considerable morbidity and mortality. However, clinical information regarding this condition is limited. This study was conducted to elucidate the full disease spectrum to improve its diagnosis and treatment.

METHOD:

We reviewed the clinical characteristics, imaging findings, and clinical courses of 14 patients diagnosed with septic pulmonary embolism caused by a K. pneumoniae liver abscess over a period of 9 years.

RESULTS:

The two most prevalent symptoms were fever and shortness of breath. Computed tomography findings included a feeding vessel sign (79%), nodules with or without cavities (79%), pleural effusions (71%), peripheral wedge-shaped opacities (64%), patchy ground-glass opacities (50%), air bronchograms within a nodule (36%), consolidations (21%), halo signs (14%), and lung abscesses (14%). Nine (64%) of the patients developed severe complications and required intensive care. According to follow-up chest radiography, the infiltrates and consolidations were resolved within two weeks, and the nodular opacities were resolved within one month. Two (14%) patients died of septic shock; one patient had metastatic meningitis, and the other had metastatic pericarditis.

CONCLUSION:

The clinical presentations ranged from insidious illness with fever and respiratory symptoms to respiratory failure and septic shock. A broad spectrum of imaging findings, ranging from nodules to multiple consolidations, was detected. Septic pulmonary embolism caused by a K. pneumoniae liver abscess combined with the metastatic infection of other vital organs confers a poor prognosis.