[Seropositivity to Helicobacter pylori among university students and their families. A comparative cross-sectional study]. / Seropositividad a Helicobacter pylori entre estudiantes universitarios y sus familias. Estudio comparativo.

OBJECTIVE: To associate serologic response to Helicobacter pylori (Hp) among seropositive university students and their families in western Mexico. METHODS: We conducted a comparative transversal study, and randomized 30 nuclear families of 14 Hp-seropositive university students and 14 Hp-seronegative university students. We carried out seropositivity measurements (IgG) to Hp using the ELISA method. An analysis was performed utilizing the chi-squared and Mann-Whitney U tests, with the aid of EPI INFO 2000 and SIGMA STAT 3.2 software. RESULTS: Global seropositivity in the families of infected students was 57 vs. 13% of the relatives of non-infected students (p = 0.000002). In families of Hp-positive students we found the following frequencies: parental (father and mother) 70%; mother 71%, and siblings 42%, while for seronegative individuals incidences were: parental 17% (p = 0.00005), mother 12% (p = 0.001), and siblings 10% (p = 0.0076). CONCLUSIONS: There is a greater prevalence of antibodies against Hp in the relatives of seropositive students.

Meningitis caused by Alcaligenes xylosoxidans in a patient with HIV/AIDS

The purpose of the present work was to inform about the first case of meningitis associated to the bacteria Alcaligenes xylosoxidans in a patient with HIV/AIDS. The patient was a 46-year-old male, with the antecedent of have been diagnosed for HIV/ AIDS, who attended in the Hospital Universitario de Colima, Mexico, with fever, shock and meningismus. The study of the cerebrospinal fluid showed pleocytosis, elevated protein levels and hypoglycorrhachia. The culture yielded the presence of Alcaligenes xylosoxidans with sensitivity to ciprofloxacin. After 14 days of treatment with this antibiotic, the patient showed neurologic improvement and was able to continue with his outpatient antiretroviral treatment. The present case shows the importance of the inclusion of this bacterium in the differential diagnosis of the neurological infections in HIV/AIDS patients and emphasizes the importance of considering the bacterial meningitis in this population.

Meningitis caused by Alcaligenes xylosoxidans in a patient with HIV/AIDS.

The purpose of the present work was to inform about the first case of meningitis associated to the bacteria Alcaligenes xylosoxidans in a patient with HIV/AIDS. The patient was a 46-year-old male, with the antecedent of have been diagnosed for HIV/ AIDS, who attended in the Hospital Universitario de Colima, Mexico, with fever, shock and meningismus. The study of the cerebrospinal fluid showed pleocytosis, elevated protein levels and hypoglycorrhachia. The culture yielded the presence of Alcaligenes xylosoxidans with sensitivity to ciprofloxacin. After 14 days of treatment with this antibiotic, the patient showed neurologic improvement and was able to continue with his outpatient antiretroviral treatment. The present case shows the importance of the inclusion of this bacterium in the differential diagnosis of the neurological infections in HIV/AIDS patients and emphasizes the importance of considering the bacterial meningitis in this population.

Molecular epidemiology of Entamoeba spp.: evidence of a bottleneck (Demographic sweep) and transcontinental spread of diploid parasites.

Entamoeba histolytica causes amebic colitis and liver abscess in developing countries such as Mexico and India. Entamoeba dispar is morphologically identical but is not associated with disease. Here we determined the ploidy of E. histolytica and developed PCR-based methods for distinguishing field isolates of E. histolytica or E. dispar. Fluorescence in situ hybridization showed that E. histolytica trophozoites are diploid for five "single-copy" probes tested. Intergenic sequences between superoxide dismutase and actin 3 genes of clinical isolates of E. histolytica from the New and Old Worlds were identical, as were those of E. dispar. These results suggest a bottleneck or demographic sweep in entamoebae which infect humans. In contrast, E. histolytica and E. dispar genes encoding repeat antigens on the surface of trophozoites (Ser-rich protein) or encysting parasites (chitinase) were highly polymorphic. chitinase alleles suggested that the early axenized strains of E. histolytica, HM-1 from Mexico City, Mexico, and NIH-200 from Calcutta, India, are still present and that similar E. dispar parasites can be identified in both the New and Old Worlds. Ser-rich protein alleles, which suggested the presence of the HM-1 strain in Mexico City, included some E. histolytica genes that predicted Ser-rich proteins with very few repeats. These results, which suggest diversifying selection at chitinase and Ser-rich protein loci, demonstrate the usefulness of these alleles for distinguishing clinical isolates of E. histolytica and E. dispar.