Jaime Labarca

Saccharomyces cerevisiae fungemia after Saccharomyces boulardii treatment in immunocompromised patients.

Saccharomyces cerevisiae is widely used as a probiotic compound. Clinical data suggest that this agent is safe and effective. We report two cases of fungemia caused by S. cerevisiae occurring in immunosuppressed patients treated orally with S. boulardii Molecular typing confirmed clonality in isolate strains from patients and the capsule. Physicians caring for immunosuppressed patients must be aware of this potential serious complication of probiotic use.

Evolution of methicillin-resistant Staphylococcus aureus clones in Latin America

OBJECTIVES Methicillin-resistant Staphylococcus aureus (MRSA) is a prominent nosocomial bacterial pathogen, associated with significant morbidity and mortality. The global incidence is increasing, and Latin America is no exception. This article reviews MRSA clonal distribution in Latin America and implications for clinical practice. DESIGN A PubMed literature search (1966-2008) identified 32 articles that characterized MRSA clones in Latin America. RESULTS Data from these articles show that since 1990, several epidemic MRSA clones have spread in Latin America. The multidrug-resistant Brazilian clone is widespread, especially in Brazil and Argentina, but more recently clones with susceptibility to a range of antibiotics have been detected in Brazil, whereas in Argentina, as in Chile, Colombia and Paraguay, the multidrug-resistant Cordobes/Chilean clone prevails. In Mexico, the New York/Japan clone is most frequent. Data were not available from every country and, despite the increasing prevalence of community MRSA infections, most were collected from tertiary care centers. CONCLUSIONS A variety of epidemic MRSA clones are circulating in Latin America, some of which harbor genes that encode multidrug resistance or enhanced pathogenicity. Continued collection and reporting of epidemiological data is crucial for effective prevention and treatment.

Outbreak of Stenotrophomonas maltophilia Bacteremia in Allogenic Bone Marrow Transplant Patients: Role of Severe Neutropenia and Mucositis

From March 1997 through November 1997, 8 allogenic bone marrow transplant (BMT) patients developed Stenotrophomonas maltophilia bacteremia on the hematology service at UCLA Medical Center (Los Angeles). Five of these patients had undergone transplantation during the same hospitalization that S. maltophilia bacteremia was detected (case patients). Compared with 7 concurrently hospitalized allogenic BMT patients (control patients), the 5 case patients were more likely to have been hospitalized in room A (P=.045), to have severe neutropenia on the culture date (P=.028), to have a longer duration of severe neutropenia (P=.05), to have severe mucositis (P=. 028), and to have received total parenteral nutrition (P=.028). Pulsed-field gel electrophoresis revealed that 2 of 3 isolates from case patients hospitalized in room A were identical. In allogenic BMT patients, severe neutropenia and severe mucositis may promote infection with S. maltophilia by impairing host defenses.

Epidemiology of meticillin-resistant Staphylococcus aureus (MRSA) in Latin America

Methicillin-resistant Staphylococcus aureus (MRSA) has become a serious threat to public health worldwide. Ongoing surveillance is essential to support infection control committees and clinicians in the prevention and treatment of infection. However, in Latin America, resources for monitoring the changing epidemiology of MRSA remain limited. In this article, we review the current situation of MRSA in Latin America in order to highlight the need for a more harmonised effort to improve its management. Literature in the PubMed and SciELO databases as well as the website of the Pan American Health Organization were searched for articles and information about the epidemiology of MRSA in Latin America. MRSA is already the leading cause of nosocomial infection in the Latin American region, and the number of reports of community-acquired MRSA infections is also rising. However, the extent of the problem is not fully understood, especially since data tend to come from large hospitals whereas much of the population is served by small community healthcare centres that do not have extensive facilities for performing microbiological surveillance. In conclusion, wider-reaching and co-ordinated programmes to provide regular MRSA surveillance reports are required across the Latin American region.

Extended spectrum β-lactamase producers among nosocomial Enterobacteriaceae in Latin America

To review the epidemiology of nosocomial extended spectrum β-lactamase-producing Enterobacteriaceae in Latin America, a systematic search of the biomedical literature (PubMed) was performed for articles published since 2005. Rates of nosocomial infections caused by extended spectrum β-lactamase-producing Enterobacteriaceae in Latin America have increased since 2005. Up to 32% of Escherichia coli and up to 58% of Klebsiella pneumoniae isolates are extended spectrum β-lactamase-positive, rates that are higher than in other world regions. From a region-wide perspective, 11-25% of E. coli isolates and 45-53% of K. pneumoniae isolates were nonsusceptible to third-generation cephalosporins. At the country level, there was a wide range in Enterobacteriaceae resistance rates to third-generation cephalosporins, with especially high rates of resistance to E. coli in Guatemala, Honduras, and Mexico, and high resistance rates to Klebsiella spp. in Argentina, Brazil, Chile, Guatemala, Honduras, and Paraguay. Susceptibility of extended spectrum β-lactamase-producing Enterobacteriaceae to cefepime, fluoroquinolones, ampicillin/sulbactam, aminoglycosides, and piperacillin/tazobactam has also been compromised, leaving the carbapenems, tigecycline, and colistin as the only antibiotics with >90% susceptibility rates. There is a steady increase in the prevalence and types of extended spectrum β-lactamases produced by Enterobacteriaceae isolates in Latin American hospitals (particularly CTX-Ms), suggesting endemic conditions overlaid by clonal outbreaks. Appropriate treatment decisions and infection control strategies informed by surveillance of regional and local susceptibilities and mechanisms of resistance are required to mitigate this major public health concern.

Carbapenem resistance in Pseudomonas aeruginosa and Acinetobacter baumannii in the nosocomial setting in Latin America

Abstract Increasing prevalence of carbapenem-resistant Pseudomonas aeruginosa and Acinetobacter baumannii strains in the nosocomial setting in Latin America represents an emerging challenge to public health, as the range of therapeutic agents active against these pathogens becomes increasingly constrained. We review published reports from 2002 to 2013, compiling data from throughout the region on prevalence, mechanisms of resistance and molecular epidemiology of carbapenem-resistant strains of P. aeruginosa and A. baumannii. We find rates of carbapenem resistance up to 66% for P. aeruginosa and as high as 90% for A. baumannii isolates across the different countries of Latin America, with the resistance rate of A. baumannii isolates greater than 50% in many countries. An outbreak of the SPM-1 carbapenemase is a chief cause of resistance in P. aeruginosa strains in Brazil. Elsewhere in Latin America, members of the VIM family are the most important carbapenemases among P. aeruginosa strains. Carbapenem resistance in A. baumannii in Latin America is predominantly due to the oxacillinases OXA-23, OXA-58 and (in Brazil) OXA-143. Susceptibility of P. aeruginosa and A. baumannii to colistin remains high, however, development of resistance has already been detected in some countries. Better epidemiological data are needed to design effective infection control interventions.

Current status of carbapenemases in Latin America

Enterobacteriaceae and non fermenting Gram-negative bacilli have become a threat to public health, in part due to their resistance to multiple antibiotic classes, which ultimately have led to an increase in morbidity and mortality. β-lactams are currently the mainstay for combating infections caused by these microorganisms, and β-lactamases are the major mechanism of resistance to this class of antibiotics. Within the β-lactamases, carbapenemases pose one of the gravest threats, as they compromise one of our most potent lines of defense, the carbapenems. Carbapenemases are being continuously identified worldwide; and in Latin America, numerous members of these enzymes have been reported. In this region, the high incidence of reports implies that carbapenemases have become a menace and that they are an issue that must be carefully studied and analyzed.

Pandemic influenza A (H1N1) in HIV-1-infected patients.

Objective:To characterize the clinical presentation, course and mortality of pandemic influenza in HIV-1-infected patients in Santiago, Chile. Methods:Prospective observational study. Results:Thirty patients were included (three hospitalized), 93% were on HAART, mean CD4+ cell count was 423 cells/μl and viral load was undetectable in 77% of patients. All patients had fever, 90% had cough, 80% had myalgias, 70% had pharyngeal congestion, 47% had coryza, 47% had odynophagia, 37% had headache and 23% had vomiting. Four patients developed pneumonia. All patients received antiviral therapy and no patient died. Conclusions:HIV patients infected by the new influenza A pandemic (H1N1) virus behave similarly to the general population.

Emergence of the 16S rRNA methylase RmtG in an extended-spectrum-β-lactamase-producing and colistin-resistant Klebsiella pneumoniae isolate in Chile.

While carbapenemases are disseminating worldwide in Enterobacteriaceae, and particularly in Escherichia and Klebsiella pneumoniae ([1][1]), therapeutic options increasingly rely on very few choices ([2][2]). Although colistin and tigecycline are now considered last-resort antibiotics for treating

KPC-producing Klebsiella pneumoniae, finally targeting Turkey

We report here the first identification of the worldwide spread of Klebsiella pneumoniae carbapenemase-2-producing and carbapenem-resistant K. pneumoniae clone ST258 in Turkey, a country where the distantly-related carbapenemase OXA-48 is known to be endemic. Worryingly, this isolate was also resistant to colistin, now considered to be the last-resort antibiotic for carbapenem-resistant isolates.