Bacteremia In HIV-infected Patients Research Articles

Fluoroquinolone antibiotics: in vitro antibacterial and time-kill bactericidal evaluation against etiology of bacteremia in human immunodeficiency virus (HIV)-infected patients

BackgroundBacteremia constitutes a significant public health challenge and represents a vital cause of morbidity and mortality in HIV-infected patients, and fluoroquinolones are commonly prescribed antibiotics due to their range of activities and pharmacokinetic profiles. This study the evaluated antibacterial activities and time-kill kinetics of fluoroquinolone antibiotics: Ofloxacin (OFL), Ciprofloxacin (CIP) and Levofloxacin (LEV) against the etiology of bacteremia of genera Staphylococcus, Streptococcus, Acinetobacter, Pseudomonas, Klebsiella, Haemophilus, Enterobacter, and Salmonella using disc diffusion, micro-broth dilution and plate count techniques.ResultsThe lowest mean growth inhibition zones (mm ± SD) of OFL, LEV, and CIP against the isolates were 10.5 ± 0.0, 10.1 ± 0.1 and 9.6 ± 0.3, respectively. The MIC values of OFL, LEV and CIP on isolates ranged from 6.25 to > 50 µg/mL, MBC ranged from 12.5 to > 50 µg/mL, while MBC/MIC ratios were ≤ 2. The time-kill assay revealed that logarithmic reductions in viable cell counts (Log10 CFU/mL) of bacteria exposed to OFL, LEV and CIP ranged from 0.17 to 2.14 for P. aeruginosa; 0.13 to 1.31 for H. influenzae; 0.04 to 2.23 for Acinetobacter spp; and 0.08 to 2.08 for K. pneumoniae. LEV and OFL (1 × MIC concentration) achieved bactericidal effects on S. typhi ST07 and E. aerogenes EA01 at 30 h post-inoculation, respectively, while ≥ 99.9% reduction in the number of viable K. pneumoniae cells exposed to CIP was achieved at 24 h post-inoculation.ConclusionThe fluoroquinolones demonstrated higher inhibitory activities at higher concentrations against the etiology of bacteremia in HIV-infected patients, signifying a concentration-dependent inhibition of bacterial growth. The MIC-based time-kill curve analyses showed that LEV achieved 3 Log10-fold reduction (≥ 99.9% reduction) in CFU/mL of most etiology of bacteremia faster compared with the other two fluoroquinolones.

Nontyphoidal Salmonella bacteremia in antiretroviral therapy-naïve HIV-infected individuals at three public hospitals in Eastern Ethiopia: prevalence, antimicrobial susceptibility patterns, and associated factors.

BackgroundNontyphoidal Salmonella bacteria have emerged as the prominent cause of severe and life-threatening bacteremia in HIV-infected patients. Antimicrobial resistance is another concern that adversely affects the health outcome of the patients. This study investigated the prevalence, antimicrobial susceptibility pattern of the isolates, and associated factors of nontyphoidal Salmonella bacteremia among antiretroviral therapy-naïve HIV-infected adult individuals at three public hospitals in Eastern Ethiopia.MethodsA cross-sectional study was conducted among 170 antiretroviral therapy-naïve HIV-infected adult individuals in three public hospitals in Eastern Ethiopia from June 2017 to June 2018. Data on sociodemographic and associated factors were collected using a pretested structured questionnaire. Blood specimens were examined for nontyphoidal Salmonella using the recommended culture and serological methods. Data were analyzed using the Statistical Package for Social Sciences version 20.0. Bivariate and multivariate logistic regression models were used to identify the predictors of nontyphoidal Salmonella bacteremia. A P-value <0.05 was considered as statistically significant.ResultsThe prevalence of nontyphoidal Salmonella bacteremia was 10% (95% CI: 5.93–15.54). A lack of hand washing habit before food preparation (adjusted odds ratio [AOR]: 13.1, 95% CI: 10.40–15.30) and a CD4+ count <200 cells/µL (AOR: 3.61, 95% CI: 1.74–5.25) were found to be significantly associated with nontyphoidal Salmonella bacteremia. Most isolates were sensitive to gentamycin (76.5%), ciprofloxacin (70.5%), and ceftriaxone (58.8%), but resistant to tetracycline (88.2%), chloramphenicol (76.5%), ampicillin (70.6%), and sulfamethoxazole–trimethoprim (70.6%).ConclusionThe prevalence of nontyphoidal Salmonella bacteremia was high. HIV-infected patients who did not wash their hands before food preparation and those whose CD4+ count was <200 cells/µL had significantly higher odds of nontyphoidal Salmonella bacteremia. Tetracycline, chloramphenicol, ampicillin, and sulfamethoxazole–trimethoprim should not be used for the treatment of nontyphoidal Salmonella bacteremia. The treatment needs to be supported by culture isolation and antimicrobial susceptibility tests.

Lack of Fluoroquinolone Resistance in Non-Typhoidal Salmonella Bacteremia in HIV-Infected Patients in an Urban US Setting

Non-typhoidal salmonella (NTS) bacteremia is a significant cause of morbidity and mortality in HIV-infected individuals worldwide. Recent reports have noted increasing resistance of NTS isolates to fluoroquinolones, the recommended first-line therapy for NTS bacteremia. The outcomes and risk factors for NTS bacteremia in HIV-infected patients in an urban US setting were evaluated. From January 2002 to December 2006, 26 episodes of NTS bacteremia were identified in 16 patients. The risk factors for NTS bacteremia were low CD4 count, high viral load, and lack of antiretroviral therapy (ART). Recurrences appeared related to lack of immune reconstitution in patients not on ART. Unlike reports from Asia, no fluoroquinolone resistance was identified in any of the Salmonella strains isolated in this setting. Optimal treatment of NTS in the HIV-infected patient in the United States should include therapy with fluoroquinolones as well as attaining complete viral suppression and immune reconstitution with ART.

Polymorphic Receptors of the Innate Immune System (MBL/MASP-2 and TLR2/4) and Susceptibility to Pneumococcal Bacteremia in HIV-Infected Patients: A Case-Control Study

Some deficient genetic polymorphisms of the innate immune system have been correlated to a higher susceptibility to different infections, especially in immunocompromised patients. The possible association between an increased incidence of pneumococcal bacteremia in HIV-infected patients, and deficient polymorphisms of the mannose-binding lectin (MBL), MBL-associated serine protease 2 (MASP-2), and toll-like receptors (TLR) 2 and 4 is analyzed by means of a case-control study. HIV-infected patients with pneumococcal bacteremia. HIV-infected patients without previous pneumococcal bacteremia matched with cases by sex and CD4 count in a 2:1 ratio. Fifty-seven cases and 114 controls were studied. Demographics, HIV infection status, antiretroviral therapy, risk factors for pneumococcal disease, and genotypes of MBL2, MASP2, TLR2 and TLR4 were analyzed. The prevalence of the MBL2, MASP2, TLR2 and TLR4 gene polymorphisms was similar in both groups. No statistical significance was found (OR 0.77, IC 95% 0.27 - 2.13) when analyzing the possible association of MBL2 deficient polymorphisms with pneumococcal bacteremia. In HIV infected patients, no association between the presence of deficient polymorphisms of MBL2, MASP2, TLR2 and TLR4 and the incidence of pneumococcal bacteremia was found.

Bacteremia in adult patients with acquired immunodeficiency syndrome in the northeast of Thailand

Bacteremia is a frequent complication found in HIV-infected patients and is usually associated with a poor prognosis. This study was undertaken to describe the bacterial pathogens causing bacteremia in adult Thai HIV-infected patients, and hence to give guidance in the choice of empirical antimicrobials. Blood culture results at Srinagarind Hospital, Khon Kaen during the period January 1996 to December 2001 were retrospectively reviewed. In HIV-infected and HIV-uninfected patients, 172 and 4082 episodes of bacteremia occurred, respectively. In HIV-infected patients, community-acquired and nosocomial bacteremia were found in 78.5% and 21.5%, respectively and most were monomicrobial. Gram-negative bacteria were the main pathogens isolated in both groups of bacteremia. Escherichia coli and methicillin-resistant Staphylococcus aureus were more common pathogens causing nosocomial bacteremia in HIV-infected patients, whereas Acinetobacter spp were more common in HIV-uninfected patients. Salmonella spp, especially Salmonella groups D and B, were the most common (62.2%) pathogen in community-acquired bacteremia in HIV-infected patients whereas Escherichia coli was the most common in HIV-uninfected patients. Only a few episodes of community-acquired bacteremia in HIV-infected patients had identified sources. Co-trimoxazole resistance was common in community-acquired bacteremia caused by Gram-negative bacilli in HIV-infected patients, with Salmonella group B being more resistant to co-trimoxazole than Salmonella group D (statistically significant, p<0.001). However, resistance rates to ceftriaxone and ofloxacin were low. Bacteremia in adult HIV-infected patients was usually caused by Gram-negative bacilli in both community-acquired and nosocomial settings. Salmonella spp was the most common organism identified, especially Salmonella group B and D. Ceftriaxone or fluoroquinolones such as ofloxacin or ciprofloxacin should be used as the initial empiric therapy for HIV-infected patients with suspected bacteremia.

Helicobacter cinaedi Bacteremia in HIV-infected Patients

Although blood stream infection with Helicobacter cinaedi has been described in immunocompromised hosts, H. cinaedi infection has only been rarely reported among HIV-infected patients. We describe a series of patients seen at our institution with H. cinaedi bacteremia and review the clinical presentations and epidemiological characteristics of the previously HIV-related reported cases of H. cinaedi bacteremia in the literature between 1982 and 2005.

Bacteremia in HIV-Infected Patients: Short-Term Predictors of Mortality

Bacteremia in HIV-Infected Patients: Short-Term Predictors of Mortality

Bacteremia in HIV-infected patients: short-term predictors of mortality.

To identify characteristics associated with mortality in HIV-infected patients with bacteremia, 88 bacteremic episodes in 80 HIV-infected patients were prospectively identified over a 5-month period and observed for 30 days. Demographic, clinical, laboratory, and radiologic data were collected. Mean and median age was 41 years. Most study subjects were homosexual men. Median CD4 count was 20 cells/mm3. Gram-positive organisms predominated (65%). The most common source of bacteremia was intravascular catheters (45%). Overall mortality was 30%. A history of malignancy, three or more opportunistic infections, shock, low hemoglobin, source of bacteremia other than an intravascular catheter, resistance to therapy, and a second bacteremic episode during the study period, were all found to be independent predictors of mortality. In this cohort of HIV-infected patients, most of whom were severely immunosuppressed, several factors were found to be significantly and independently associated with mortality.

The Role of Human Immunodeficiency Virus Infection in Pneumococcal Bacteremia in San Francisco Residents

Human immunodeficiency virus (HIV) is an important risk factor for invasive pneumococcal disease, but information on clinical course and infecting serotypes is limited. To help develop strategies to reduce the morbidity due to invasive pneumococcal disease, episodes of pneumococcal bacteremia were identified by retrospective review of microbiology records (November 1983-November 1987) at 10 San Francisco hospitals and, for patients 20-55 years old living in San Francisco, HIV antibody status was determined by review of medical records. Pneumococcal isolates from one hospital were serotyped. Of 294 patients with pneumococcal bacteremia identified, 32 (11%) had AIDS at the time pneumococcal bacteremia was diagnosed and another 43 (15%) were HIV-infected but did not have AIDS; 12 HIV-infected patients developed AIDS after the episode of pneumococcal bacteremia. The rate of pneumococcal bacteremia in AIDS patients was estimated to be 9.4/1000 patient-years. Serotypes of 27 (82%) of 33 pneumococcal isolates from HIV-infected patients and 107 (90%) from 119 patients without known HIV infection were among the 23 serotypes included in the currently available polysaccharide vaccine. The rate of pneumococcal bacteremia is approximately 100-fold greater in AIDS patients in San Francisco than rates reported before the AIDS epidemic, but more than half the episodes of pneumococcal bacteremia in HIV-infected patients occurred in patients without AIDS. Data on pneumococcal serotypes causing invasive disease in HIV-infected patients suggest that the current pneumococcal vaccine, if effective in this population, could provide significant protection against pneumococcal disease.

Frequency ofMycobacterium tuberculosisBacteremia in Patients with Tuberculosis in an Area Endemic for AIDS

Mycobacterium tuberculosis bacteremia has recently been reported in patients infected with the human immunodeficiency virus (HIV). At our institution, tuberculosis occurs commonly among patients with and without HIV infection. We sought to determine the frequency of M. tuberculosis bacteremia among patients with newly diagnosed tuberculosis. During a 4-month period, mycobacterial blood cultures were obtained on all identifiable patients with newly diagnosed tuberculosis. Fifteen percent (9/59) of consecutive patients with tuberculosis had positive blood cultures for M. tuberculosis. Twenty-six percent (7/27) of patients known to be infected with HIV had positive mycobacterial blood cultures; two intravenous drug users who refused HIV-serologic testing also had positive mycobacterial blood cultures. M. tuberculosis bacteremia occurred at a higher rate among HIV-infected patients with an AIDS-defining opportunistic infection in addition to tuberculosis (3/3) than among HIV-infected patients without such an opportunistic infection (4/24; p less than 0.02). M. tuberculosis bacteremia occurred in 83% (5/6) of patients with disseminated tuberculosis and in 8% (4/53) of patients without disseminated tuberculosis (p less than 0.001). In all cases, tuberculosis was diagnosed in patients with M. tuberculosis bacteremia or else they died prior to the blood cultures demonstrating mycobacterial growth (mean time to detection of mycobacterial growth: 43 days). However, the frequent occurrence of M. tuberculosis bacteremia in HIV-infected patients with disseminated tuberculosis suggests that mycobacterial blood cultures may help confirm the diagnosis of tuberculosis in this group of patients.