ABSTRACT
INTRODUCTION: Citrobacter spp. is an opportunistic bacteria that have been recognized as significant pathogens in patients with underlying diseases or immunocompromised status. The aim of this study was to identify extended-spectrum ß-lactamases in clinical isolates of Citrobacter spp. METHODS: This cross-sectional study was conducted at Hospital Central "Dr. Ignacio Morones Prieto" in San Luis Potosi, Mexico. Nineteen isolates of Citrobacter spp. were obtained from clinical specimens between April to December 2015. Four isolates were resistant to third-generation cephalosporins. The presence of genes encoding ESBL (bla CTX-M-15, bla TEM-1, bla VEB-1, bla SHV, and bla PER-1) was analyzed by PCR. For this purpose, plasmid DNA was extracted and horizontally transferred to recipient E. coli Top 10. RESULTS: bla CTX-M-15 and bla VEB-1 genes were detected in Citrobacter freundii and Citrobacter sedlakii, whereas bla PER-1 gene was identified in 1 isolate of Citrobacter freundii. In contrast, bla SHV gene was not detected in any isolate. One strain carried bla CTX-M-15, bla TEM-1, bla VEB-1, and bla PER-1 genes, most in a 275-kb plasmid. CONCLUSION: This study shows the presence of different types of ESBL in clinical isolates of Citrobacter freundii and Citrobacter sedlakii, which confer resistance to broad-spectrum ß-lactams. The plasmid identified in this study harboring ESBL genes could play an important role in the dissemination of antibiotic resistance.
ABSTRACT
BACKGROUND: Rheumatoid arthritis is a chronic inflammatory disease whose cause has not been fully elucidated. However, genetic factors seem to have an important role in its pathogenesis. OBJECTIVE: We analyzed the possible association between rheumatoid arthritis and variants of the SLC11A1 gene, which encodes for NRAMP1, a protein involved in the activation of phagocytes and synthesis of proinflammatory cytokines. METHODS: In a case-control study in a Mexican Mestizo population, blood samples from 188 patients with rheumatoid arthritis and 133 healthy individuals were obtained to determine the frequency of SLC11A1 gene variants INT4 (469+14G/C or rs3731865), D543N (1730G/A or rs17235409) and 3'UTR (1729+55del4 or rs17235416) by polymerase chain reaction and restriction fragment length polymorphism. RESULTS: We found similar frequencies of INT4 and 3'UTR polymorphisms in patients and controls (p = 0.18 and 0.89, respectively). In contrast, a significantly lower frequency of the D543N polymorphism was observed in patients with rheumatoid arthritis compared to controls (p corrected = 0.016; OR: 0.48; 95% CI: 0.28-0.80). CONCLUSION: Our data suggest that the D543N variant of SLC11A1 gene has a protective effect in the development of rheumatoid arthritis, an interesting finding that has not been previously reported in any population.
