Characterization of Multidrug-Resistant Staphylococcus aureus Isolates and Comparison of Methods of Susceptibility to Vancomycin.

S. aureus are among the main bacteria causing problems related to multidrug resistance in nosocomial infections. Therefore, it is necessary to carry out a reliable and rapid diagnosis for the identification of the bacteria and characterization of its susceptibility profile, especially vancomycin, which is an alternative treatment against multidrug-resistant (MDR) S. aureus. Thus, the goal of this study was to characterize isolates of S. aureus regarding the resistance and virulence and to check the susceptibility to vancomycin, through different methods, for comparative purposes. Seventeen antimicrobials were tested to assess the susceptibility profile. It was evaluated the presence of identification (nuc), resistance (mecA and blaZ), biofilm (icaA and icaD) and siderophore (sfaD and sbnD) genes. The susceptibility to vancomycin was evaluated by Minimum Inhibitory Concentration (MIC) by broth microdilution (BMD), E-test, commercial panel (Kit), and Phoenix equipment. Most S. aureus (93,33%) was classified as MDR. These isolates were 100% positive for nuc, mecA, icaA, icaD, and sfaD genes; 96.67% for sbnD and 33.33% for blaZ. In relation to BMD, all methods correctly classified the susceptibility of the isolates; however, regarding the exact MIC value for vancomycin, Phoenix showed agreement of 63.33%, E-test (33.33%) and Kit (26.66%). In conclusion, most of S. aureus was considered MDR. Also, they presented resistance, biofilm production, and siderophores genes, showing the pathogenic potential of these bacteria. Besides, the Phoenix test was considered the most effective, as it presents advantages, such as identification of the microorganism and a greater number of antimicrobials tested at a time.

Case Report: Severe Visceral Leishmaniasis in a Patient with HIV Coinfection Undergoing Treatment for Erythema Nodosum Leprosum.

We report a case of visceral leishmaniasis (VL)/HIV coinfection in a patient undergoing regular antiretroviral therapy and treatment with thalidomide for erythema nodosum leprosum. He presented at a health service with high fever, chills, asthenia, pale skin, lower limb edema, hepatomegaly, and splenomegaly. Visceral leishmaniasis was confirmed by direct examination, and serological and molecular tests. Serum levels of Th1/Th2 cytokines were measured. The patient began treatment with liposomal amphotericin B, with good clinical response; however, VL recurred 6 months later. Treatment was reinitiated, maintaining secondary prophylaxis with liposomal amphotericin B. The patient showed clinical improvement with important recovery of CD4+ T-lymphocyte count.