Enteric multiplex PCR panels: A new diagnostic tool for amoebic liver abscess?

Invasive amoebiasis is a life-threatening infection requiring immediate detection and treatment. However, diagnosis is challenging because conventional methods such as light microscopy and serology are unreliable. Molecular techniques are therefore considered the new diagnostic reference standard, but most of the developed assays are research tools and not widely available. Recently commercial multiplex PCR panels have been introduced which permit the simultaneous detection of multiple enteric pathogens including Entamoeba histolytica in stool samples. Our report demonstrates for the first time that these new assays might also serve as a rapid tool to diagnose amoebic liver abscess in patients with cystic focal liver lesions.

Susceptibilidad antifúngica de Candida albicans recuperadas de pacientes con SIDA y candidiasis orofaríngea y esofágica. Experiencia con Etest / Antifungal susceptibility for Candida albicans isolated from AIDS patients with oropharyngeal and esophageal candidiasis: experience with Etest

BACKGROUND: Oropharyngeal candidiasis (OPC) and esophageal candidiasis (EPC) are frequent complications in AIDS patients. The use of Fluconazole, an effective and a low toxicity drug, has been associated to the emergency of secondary resistant strains. For this reason, in vitro antifungal susceptibility tests are necessary to predict a therapeutic failure. Etest is an easy to perform alternative test, that has showed a good agreement with the broth microdilution reference method (NCCLS, document M27-A). AIM: To measure the susceptibility of C. albicans isolates from AIDS patients complicated with OPC and EPC to Amphotericin B (AmB) and Fluconazole (Flu) using Etest. MATERIAL AND METHODS: Twenty strains from 20 AIDS patients were studied. AmB was tested in RPMI 1640 agar and Flu in Casitone agar. RESULTS: All studied strains showed minimal inhibitory concentrations (MICs) < 1 mg/mL for AmB. A highly resistant strain to Flu (> 256 mg/mL) was isolated from a patient previously treated with Flu. CONCLUSIONS: In AIDS patients with OPC and EPC, the susceptibility to Flu of the isolates should be screened, to detect resistant strains. Etest is a reliable alternative in these cases, for laboratories that cannot use the reference method.

Salmonella infections in a cancer center.

Data concerning 40 patients hospitalized in a cancer center and Salmonella infection were analyzed. Hematological malignancy was present in 24 patients (60%) and solid tumor in 14 patients (35%). Among the predisposing factors, antineoplastic chemotherapy was the most frequent (60%) followed by antacid use (47.5%), corticosteroids (37.5%), granulocytopenia below 500 neutrophils/microliters (15%), surgery (10%) and splenectomy (2.5%). Bacteremia was the most frequent clinical syndrome accounting for 42.5% of the patients. Focal infection, enteritis and carrier state accounted for the remaining 30%, 20% and 7.5% respectively. Salmonella typhimurium and S. dublin represented 65% of the isolates, with clear association between serotype dublin and bacteremia. All S. dublin isolates were resistant to chloramphenicol. Among dublin and typhimurium serotypes, 20% the isolates were resistant to the traditional antibiotics used in salmonellosis (ampicillin, chloramphenicol, cotrimoxazole). All strains were susceptible in vitro to cephalosporins. The frequency of relapse was 15% and the overall mortality (within 30 days) attributed to Salmonella infection was 15%.

Anaerobic bacteremia in a cancer center.

Seventy-five episodes of clinically relevant anaerobic bacterial bacteremia observed in cancer patients were reviewed. Gastrointestinal (22.7%), hematological (22.7%) and female genital tract (18.6%) cancers were the most common underlying malignant diseases. Among 84 strains of strict anaerobic bacteria recovered in the 75 patients, gram-negative rods were isolated in 49 patients (58.3%), gram-positive rods in 29 patients (34.5%) and gram-positive cocci in 6 patients (8%). Bacteroides spp. and Clostridium spp. were the most frequent pathogens (85.7%). Twenty-one episodes of bacteremia were polymicrobial, aerobic gram-positive cocci being the most frequently associated pathogens. When identified, the primary sites were the gastrointestinal tract (40%), the female genital tract (17.3%), skin and soft tissue (14.6%), the oropharynx (12%) and the lower respiratory tract (6.7%). The source remained unknown in 7 cases (9.3%). The overall survival (evaluated 10 days after the occurrence of bacteremia) was 82.5%. There was no difference in mortality between patients with monomicrobial and polymicrobial bacteremia. Pulmonary complications were more frequent in patients with fatal outcome in comparison to patients who survived. The mortality rate of the patients adequately treated was 10.3% compared to 41% for the patients not treated or treated inadequately (P = 0.016, chi 2).