Virulence and plasmid transferability of KPC Klebsiella pneumoniae at the Veterans Affairs Healthcare System of New Jersey.

Klebsiella pneumoniae carbapenemase (KPC)-producing Klebsiella pneumoniae infections are associated with high mortality; however, little is known about the virulence determinants of KPC-producing K. pneumoniae. At the Veterans Affairs New Jersey Healthcare System (VA NJHCS), we investigated the virulence and plasmid transferability of 60 clinically unique KPC-containing K. pneumoniae isolates. All 60 isolates were negative for known virulence factors K1, K2, and K5 capsular antigens; rmpA; and the aerobactin gene by polymerase chain reaction. Isolates varied in their susceptibility to neutrophil phagocytosis, but were less resistant than the virulent serotype K1 isolate. Additionally, no deaths were seen on murine lethality studies. Conjugation results of this study showed that the bla(KPC) gene can be transferred into an Escherichia coli J-53 strain but not to E. coli JP-995. However, the stability is very limited as E. coli J-53 does not retain bla(KPC)-containing plasmids for any period of time. The lack of virulence factors in the set of KPC-producing K. pneumoniae studied suggests that morbidity and mortality may be due to detection issues or lack of effective antibiotics.

Polymyxin Combination Therapy and the Use of Serum Bactericidal Titers in the Management of KPC-Producing Klebsiella pneumoniae Infections: A Report of 3 Cases.

Management of patients with KPC-harboring Enterobacteriaceae has become a significant and challenging scenario. We report three cases of KPC-producing Klebsiella pneumoniae bacteremia that were successfully treated using combination therapy with polymyxin B and other antimicrobials. Serum bactericidal titers were determined and provided additional clinical guidance in the management of such patients.

Phenotypic and genotypic screening and clonal analysis of carbapenem-resistant Klebsiella pneumoniae at a single hospital.

Detection of bla(KPC)-harboring Klebsiella pneumoniae (KP) in the clinical laboratory remains a difficult task. Decreased ertapenem (ERT) susceptibility has been considered one of the most sensitive phenotypic indicators of K. pneumoniae carbapenemase (KPC) production, but has been found to be nonspecific. Susceptibility testing using imipenem or meropenem lacks the sensitivity for detection of KPCs, and there is limited experience using doripenem (DOR). Fifty-five individual ERT-nonsusceptible KP isolates and 19 isolates that were ERT-susceptible, extended spectrum ß-lactamase-positive KP were collected from the clinical laboratory and tested for DOR susceptibility by Etest methodology. PCR screening for bla(KPC) was performed on all specimens. All but three isolates with ERT resistance were KPC positive by PCR. Compared to PCR, ERT detection of KPC had a sensitivity of 98% and a false-positive rate of 6%. Overall, there was a 97% agreement between ERT and DOR susceptibility results. However, there was one KPC-positive isolate that was discrepant (ERT susceptible, DOR nonsusceptible by Etest). Selected isolates of KP from both groups underwent pulsed-field gel electrophoresis analysis to determine the degree of genetic relatedness of KPC-positive and KPC-negative isolates. Pulsed-field gel electrophoresis of selected KPC-positive and KPC-negative KP identified a common pattern between both groups. The resistance to DOR and/or ERT is sensitive and a specific indicator for detection of bla(KPC) in KP.

Impact of adding maraviroc to antiretroviral regimens in patients with full viral suppression but impaired CD4 recovery.

We reviewed the effect of adding maraviroc on CD4 cell counts in nine patients on antiretroviral therapy with full viral suppression but impaired CD4 cell recovery. There were no significant differences in changes in CD4 cell count, percentage of CD4 cells, or in the ratio of CD4/CD8 cells at 30 days and 25 weeks of maraviroc therapy. Plasma endotoxin levels measured in four patients before and during maraviroc treatment also showed no significant differences.

Prosthetic Joint Infection due to Mycobacterium bovis after Intravesical Instillation of Bacillus Calmette-Guerin (BCG).

Intravesical instillation of Bacillus Calmette-Guerin (BCG) is a treatment to prevent recurrence of superficial urothelial bladder carcinoma. Complications after bladder instillation of BCG have been reported including locally invasive and systemic infections due to dissemination of Mycobacterium bovis from the bladder. We present an uncommon case and literature review of prosthetic joint infection due to M. bovis after intravesical BCG treatment of bladder cancer.

Identification of carbapenem-resistant klebsiella pneumoniae harboring KPC enzymes in New Jersey.

Klebsiella pneumoniae isolates harboring KPC enzymes have been identified in many geographical areas since 2001. Numerous problems exist in the detection and treatment of patients with such isolates. The clinical characteristics and molecular epidemiology associated with 12 randomly chosen patients in whom these enzymes were detected by molecular methods are described. This is the first description of the identification of carbapenem-resistant K. pneumoniae isolates harboring KPC beta-lactamases at the Veterans Administration Hospital in New Jersey (VA NJHCS). Because recognition of carbapenem resistance in K. pneumoniae due to KPC enzymes can only be achieved by molecular methods, detection in the Clinical Microbiology Laboratory by routine methods will continue to be difficult, leading to dilemmas in treatment.

Relationship between fluoroquinolone use and changes in susceptibility to fluoroquinolones of selected pathogens in 10 United States teaching hospitals, 1991-2000.

We retrospectively examined the relationship between fluoroquinolone use and the susceptibilities of 11 bacterial pathogens to fluoroquinolones in 10 US teaching hospitals from 1991 through 2000. Statistical significance was determined by 2-way analysis of variance, with the number of isolates tested each year as a weighting factor. The analysis of baseline-to-end point change in the percentage of susceptibility and the slope of the regression line (trend line) for logit percentage of susceptibility showed that the overall percentage of susceptibility to fluoroquinolones decreased significantly during the study period (P<.05) and that change in percentage of susceptibility was significantly related to change in fluoroquinolone use (P<.05). Particularly notable were the decreases in the susceptibilities of Pseudomonas aeruginosa, Proteus mirabilis, and Escherichia coli (decreases of 25.1%, 11.9%, and 6.8%, respectively).

Are three sputum acid-fast bacillus smears necessary for discontinuing tuberculosis isolation?

To evaluate the efficacy of three sputum acid-fast bacillus (AFB) smears to rule out pulmonary tuberculosis, sputum AFB smear and culture results were analyzed at two university-affiliated teaching hospitals. The negative predictive value of the smear increased by only 0.2% on days 2 and 3 each, indicating that in low-prevalence populations, there is limited value in requiring three negative sputum AFB smears before discontinuing tuberculosis isolation.

Prevalence of hepatitis C and coinfection with HIV among United States veterans in the New York City metropolitan area.

OBJECTIVES: The aims of this study were to determine the prevalence of hepatitis C virus (HCV) infection and its risk factors, as well as the prevalence of coinfection with HIV and its risk factors, among patients with confirmed HCV infection. METHODS: In a 1-day cross-sectional HCV survey at six Veterans Affairs Medical Centers in the New York City metropolitan area, all 1943 patients undergoing phlebotomy for any reason were asked to be tested for HCV antibody by enzyme immumoassay (EIA). A total of 1098 patients (57%) agreed to HCV testing, 1016 of whom also completed a questionnaire on demographics and HCV risk factors. All HCV EIA(+) samples were confirmed by HCV RNA and HCV recombinant immunoblot assay (RIBA) antibody testing and were also tested for HCV viral load, HCV genotype, and antibodies to HIV in a blinded fashion. RESULTS: The prevalence of confirmed HCV infection was 10.6% (95% CI = 8.7-12.4%), and the prevalence of HCV viremia was 8.2% (95% CI = 6.6-9.8%). The rate of HCV viremia among anti-HCV(+) patients was 77.6%, and HCV genotype 1 was present in 87.5% of viremic patients. Independent risk factors for HCV infection were injection drug use (OR = 35.6, 95% CI = 16.9-75.2), blood exposure during combat (OR = 2.6, 95% CI = 1.2-5.7), alcohol abuse (OR = 2.4; 95% CI = 1.2-4.8), and service in the Vietnam era (OR = 2.1; 95% CI = 1.0-4.5). Coinfection with HIV was present in 24.8% of anti-HCV(+) patients. The only independent risk factor for coinfection was age <50 yr (OR = 3.7, 95% CI = 1.1-12.1). CONCLUSIONS: U.S. veterans who are receiving medical care at VA medical centers in the New York City metropolitan area have a much higher rate of chronic hepatitis C than the general population, with a high frequency of genotype 1. Coinfection with HIV is very common in patients with confirmed HCV infection, and these patients should routinely be offered HIV testing.