Increasing prevalence and dissemination of invasive nontyphoidal Salmonella serotype Typhimurium with multidrug resistance in hospitalized patients from southern Brazil

ABSTRACT Introduction: Nontyphoidal Salmonella serotypes are the main cause of human food-borne infection, including several hospitalization cases in the developing countries. Aim: To detect the main serotypes and to characterize the antibiotic resistance of human non-enteric and enteric nontyphoidal Salmonella from clinical isolates in Brazil. Methods: Salmonella serotypes were identified by microbiological and molecular methods. Susceptibility testing to antibiotics was performed by agar disk diffusion. Real-time PCRs were carried out for the detection of the genus Salmonella as well as serotypes Typhimurium and Enteritidis. Results: A total of 307 nontyphoidal Salmonella were isolated from 289 different patients in a reference laboratory (LACEN-RS) from Southern Brazil in a six-year period (2010-2015). There were 45 isolates from emerging cases and 244 from sporadic cases in hospitalized patients. Non-enteric isolates were detected in 42.6% of the patients from sources such as urine, blood and other clinical fluids. Serological and PCR-specific tests demonstrated that Typhimurium (48.4%) and Enteritidis (18.3%) were the most frequent serotypes. Typhimurium isolates were generally resistant to three or more antibiotic classes, while Enteritidis isolates to one or two classes. Typhimurium was the most frequent serotype in all samples (48.4%), mainly among the hospitalized patients (55.6%), and presented the highest rates of multidrug resistance (59.3% of the isolates of this serotype). Further, the prevalence of this serotype increased along the years of the study in comparison to other nontyphoidal Salmonella serotypes. Conclusion: Greater public health attention should be given to prevent salmonellosis in the community and in hospital settings to reduce the rates of Typhimurium strains with multidrug resistance.

Hepatitis C in hemodialysis: the contribution of injection drug use

BACKGROUND: Hepatitis C virus (HCV) infection is the most common cause of acute or chronic hepatitis in patients on hemodialysis (HD). The purpose of this study was to describe the prevalence of positive HCV RNA and investigate injection drug use as an emerging risk factor in patients with chronic renal disease on HD. METHODS: This was a multicenter cross-sectional study with 325 patients with chronic renal disease on HD in the period between August 1, 2005 to August 30, 2006, receiving care at four institutions in the city of Porto Alegre, Southern Brazil. Epidemiological data were collected by means of a structured questionnaire. The following laboratory tests were performed: alanine aminotransferase (ALT), anti-hepatitis C virus antibodies (anti-HCV), and qualitative polymerase chain reaction (PCR). RESULTS: Of 325 patients, 68 had positive HCV RNA results. The comparison between patients with positive and negative PCR results revealed significant differences in duration of HD (mean = 71 versus 52.4 months; p = 0.02); previous blood transfusion (92 percent versus 72 percent; p < 0.01); injection drug use (13 percent versus 0.7 percent; p < 0.01); anti-HCV positivity at start of HD therapy (60 percent versus 4 percent; p < 0.01); and mean ALT value (39 versus 26.5; p < 0.01). Logistic regression analysis showed a positive HCV RNA independently associated to being on HD for more than five years [OR: 2.1 (95 percent CI 1.2 -3.8)]; previous blood transfusion [OR: 3.7 (95 percent CI 1.4 - 9.5)]; and injection drug use [OR: 22.6 (95 percent CI 4.2 - 119.6)]. CONCLUSION: Injection drug use was an independent risk factor for HCV infection among chronic renal disease patients on HD.