[Group B streptococcal perinatal infection: A Global, Latin American and Mexican Overview]. / Infección perinatal por estreptococo del grupo B: panorama global, en América Latina y en México.

Group B streptococci (Streptococcus agalactiae) cause a number of infections in women during pregnancy and postpartum, such as urinary tract infection, chorioamnionitis and endometritis, consequently may affect the newborn. Group B streptococci is the most common cause of severe infections in newborns in developed countries. Studies on the epidemiology of group B streptococci infections in Latin America are still limited. This information is also unknown in Mexico, but studies carried out in the center of the country have found high rates of vaginal colonization in pregnant women and there are case series and case reports of newborns. Microbiological and molecular epidemiology studies in Mexico have shown that populations of group B streptococci have a clonal distribution and that there are clones with genetic and phenotypic characteristics of high virulence that appear to be responsible for most of perinatal pathology. However, the actual role of group B streptococci in perinatal pathology in Mexico is unknown. Consequently, whether to perform or not the screening for determining the group B streptococci colonization status in pregnant women, and the indication or not for intrapartum antibiotic prophylaxis to prevent neonatal group B streptococci infection in Mexico, are still controversial.

Comparative Mycobacterium tuberculosis spoligotype distribution in Mexico.

In the present work, we studied the genetic diversity of Mycobacterium tuberculosis clinical isolates from patients according to their gender, age, and geographic location in Mexico. We did not observe any statistically significant differences in regard to age or gender. We found that spoligo international type 53 (SIT53) is more frequent in the northern states and that SIT119 predominates in central Mexico.

Molecular epidemiology and drug resistance of Mycobacterium tuberculosis in a tertiary care hospital in northeastern Mexico.

INTRODUCTION: Tuberculosis (TB) is a re-emerging disease considered a public health concern. In the present study, we analyzed the epidemiology and drug resistance of Mycobacterium tuberculosis strains isolated from patients with pulmonary TB. METHODOLOGY: Mycobacterium tuberculosis isolates (n = 190) were obtained from patients with pulmonary TB admitted to Dr. José Eleuterio González University Hospital (UH). Each M. tuberculosis isolate was analyzed by spoligotyping (spacer oligonucleotide typing) and MIRU-VNTR (Mycobacterial Interspersed Repetitive Units-Variable Number Tandem Repeat). Drug resistance was evaluated using the Anyplex™ II MTB/MDR/XDR assay. RESULTS: The predominant spoligotypes observed were X1 (SIT 119, n = 46), T1 (SIT 53, n = 40), H3 (SIT 50, n = 13), Beijing (SIT 1, n = 11), and EAI2-Manila (SIT 19, n = 8). MIRU-VNTR analysis showed that the locus QUB-26 had the highest allelic variability. The observed drug resistance included monoresistance to rifampicin (2.6%; n = 5), isoniazid (3.2%; n = 6), and fluoroquinolones (1.6%; n = 3) as well as multidrug resistance (5.3%; n = 10). All of the Beijing strains were susceptible. Regarding comorbidities, 13.7% (26/190) of the patients were co-infected with TB and HIV (TB+HIV+), and 31.6% (55/190) had TB along with diabetes (TB + diabetes). CONCLUSIONS: The most prevalent lineages were X1 (SIT 119; 24.3%) and T1 (SIT 53; 21%). An alarming proportion (12.6%) of M. tuberculosis isolates presented drug resistance. To effectively manage TB, continuous surveillance of regional strain dissemination, drug resistance profiles, and TB-associated comorbidities is crucial.

p16INK4a and pRb expression in laryngeal squamous cell carcinoma with and without infection by EBV or different genotypes of HPV: a retrospective study.

BACKGROUND: Laryngeal squamous cell carcinoma (LSCC) represents one of the principal tumors of the head and neck. Human papillomavirus (HPV) and Epstein-Barr virus (EBV) are considered risk factors for the development and the clinical prognosis of LSCC. High levels of p16INK4a are suggested as a surrogate marker of HPV or EBV infection in some head and neck tumors but in LSCC is still controversial. Furthermore, pRb expression may be considered an additional biomarker but it has not been clearly defined. This work aimed to compare the expression of pRb and p16INK4a as possible biomarkers in tumor tissues with and without infection by EBV or different genotypes of HPV from patients with LSCC. METHODS: Tumor samples from 103 patients with LSCC were previously investigated for the presence and genotypes of HPV using the INNO-LiPA line probe assay and for the infection of EBV by qPCR. p16 INK4a and pRb expression was assessed by immunohistochemistry. RESULTS: Of the 103 tumor samples, expression of p16INK4a was positive in 55 (53.4%) and of this, 32 (56.1%) were positive for HPV whereas 11 (39.3%) were EBV positive but both without a significantly difference (p > 0.05). pRb expression was positive in 78 (75.7%) and a higher frequency of this expression was observed in HPV negative samples (87.0%) (p = 0.021) and in high-risk HPV negative samples (85.2%) (p = 0.010). No difference was observed when comparing pRb expression and EBV infection status (p > 0.05). CONCLUSION: Our results support the suggestion that p16INK4a is not a reliable surrogate marker for identifying HPV or EBV infection in LSCC. On the other hand, most of our samples had pRb expression, which was more frequent in tumors without HPV, suggesting that pRb could indicate HPV negativity. However, more studies with a larger number of cases are required, including controls without LSCC and evaluating other molecular markers to determine the real role of p16INK4a and pRb in LSCC.

Genomic analysis of virulence factors and antimicrobial resistance of group B Streptococcus isolated from pregnant women in northeastern Mexico.

INTRODUCTION: Group B Streptococcus (GBS) causes infections in women during pregnancy and puerperium and invasive infections in newborns. The genes lmb, cylE, scpB, and hvgA are involved with increased virulence of GBS, and hypervirulent clones have been identified in different regions. In addition, increasing resistance of GBS to macrolides and lincosamides has been reported, so knowing the patterns of antibiotic resistance may be necessary to prevent and treat GBS infections. This study aimed to identify virulence genes and antibiotic resistance associated with GBS colonization in pregnant women from northeastern Mexico. METHODS: Pregnant women with 35-37 weeks of gestation underwent recto-vaginal swabbing. One swab was inoculated into Todd-Hewitt broth supplemented with gentamicin and nalidixic acid, a second swab was inoculated into LIM enrichment broth, and a third swab was submerged into a transport medium. All samples were subcultured onto blood agar. After overnight incubation, suggestive colonies with or without hemolysis were analyzed to confirm GBS identification by Gram staining, catalase test, hippurate hydrolysis, CAMP test, and incubation in a chromogenic medium. We used latex agglutination to confirm and serotype GBS isolates. Antibiotic resistance patterns were assessed by Vitek 2 and disk diffusion. Periumbilical, rectal and nasopharyngeal swabs were collected from some newborns of colonized mothers. All colonized women and their newborns were followed up for three months to assess the development of disease attributable to GBS. Draft genomes of all GBS isolates were obtained by whole-genome sequencing. In addition, bioinformatic analysis to identify genes encoding capsular polysaccharides and virulence factors was performed using BRIG, while antibiotic resistance genes were identified using the CARD database. RESULTS: We found 17 GBS colonized women out of 1154 pregnant women (1.47%). None of the six newborns sampled were colonized, and no complications due to GBS were detected in pregnant women or newborns. Three isolates were serotype I, 5 serotype II, 3 serotype III, 4 serotype IV, and 2 serotype V. Ten distinct virulence gene profiles were identified, being scpB, lmb, fbsA, acp, PI-1, PI-2a, cylE the most common (3/14, 21%). The virulence genes identified were scpB, lmb, cylE, PI-1, fbsA, PI-2a, acp, fbsB, PI-2b, and hvgA. We identified resistance to tetracycline in 65% (11/17) of the isolates, intermediate susceptibility to clindamycin in 41% (7/17), and reduced susceptibility to ampicillin in 23.5% (4/17). The tetM gene associated to tetracyclines resistance was found in 79% (11/14) and the mel and mefA genes associated to macrolides resistance in 7% (1/14). CONCLUSIONS: The low prevalence of colonization and the non-occurrence of mother-to-child transmission suggest that the intentional search for GBS colonization in this population is not justified. Our results also suggest that risk factors should guide the use of intrapartum antibiotic prophylaxis. The detection of strains with genes coding virulence factors means that clones with pathogenic potential circulates in this region. On the other hand, the identification of decreased susceptibility to antibiotics from different antimicrobial categories shows the importance of adequately knowing the resistance patterns to prevent and to treat GBS perinatal infection.

[First case of HIV-1 subtype C infection in Mexico]. / Infección por VIH-1 subtipo C. Primer caso informado en México.

We herein report the first case of HIV-1 subtype C described in Mexico, which was detected in a South African patient who died in Mexico of an AIDS-related non-Hodgkin lymphoma. Although HIV-1 subtype B is the predominant virus circulating in Mexico, the case reported highlights the importance of molecular monitoring of the spreading of HIV-1 subtypes.

[Dialyzed leukocyte extracts for the treatment of recurrent and severe infections in pediatric patients with cellular immunodeficiency: 15 years of experience]. / Extractos dializados de leucocitos para el tratamiento de infecciones recurrentes y severas en pacientes pediátricos con inmunodeficiencia celular: 15 años de experiencia.

BACKGROUND: Dialyzable leukocyte extracts (DLE) have been used to treat several cellular immunodeficiency. OBJECTIVE: To review the experience of a tertiary hospital in the use of DLE for the treatment of recurrent or severe infections in children with acquired cellular immunodeficiency not due to HIV. METHODS: We reviewed the medical records of all children who received treatment with EDL of human or bovine origin between 1986 and 2000 to detect recurrent or severe infections without response to a specific antimicrobial therapy and with a quantitative or qualitative deficit in the cellular immune response. The dose of DLE was adjusted according to the percentage of T lymphocytes; the evolution of the patient was evaluated retrospectively for 5 years, the immune response was evaluated by subpopulation of lymphocytes and intradermal tests and inhibition of the leukocyte migration assay (LIF) to PPD, coccidioidin, varidase and candidin. RESULTS: 150 children received DLE, age 7.0 ± 5.9 years. The most frequent indications included upper respiratory tract (71%), lower respiratory tract (43%), gastrointestinal tract (15%), urinary tract (15%) and neurological infections (4%) and coccidioidomycosis (3%). After starting the DLE, the numbers of T lymphocytes, LIF to PPD and varidase (> 20%) and the intradermal induration of the test increased (p <0.001). In 6 patients (4%) recurrences of respiratory and gastrointestinal tract infections were observed, which resolved, no adverse effects attributable to the DLE were reported. CONCLUSIONS: The use of DLE for recurrent or severe infectious processes in children with cellular immune deficit improved the clinical evolution and the immunological parameters evaluated without adverse effects attributable to their use.

Antecedentes: Los extractos dializados de leucocitos (EDL) han sido utilizados en el tratamiento de diversos defectos de la inmunidad celular. Objetivo: Revisar la experiencia en el uso de EDL para tratar infecciones recurrentes o severas en niños con inmunodeficiencia celular adquirida no debida a virus de la inmunodeficiencia oportuna. Métodos: Se revisaron expedientes de niños tratados con EDL humano o bovino entre 1986 y 2000, por infecciones recurrentes o severas sin respuesta a antimicrobianos y con déficit en la respuesta inmune celular. La dosis se ajustó por el porcentaje de poblaciones de linfocitos T. En el seguimiento a cinco años, la respuesta inmune se evaluó por subpoblaciones de linfocitos, intradermorreacción e inhibición de la migración de leucocitos (LIF) a PPD, coccidioidina, varidasa y candidina. Resultados: 150 niños recibieron EDL, edad 7.0 ± 5.9 años. Las indicaciones más frecuentes incluyeron infección respiratoria superior (71 %), respiratoria inferior (43 %), gastrointestinal (15 %), urinaria (15 %), neuroinfección (4 %) y coccidioidomicosis (3 %). Se incrementaron los linfocitos T, el LIF a PPD y varidasa (> 20 %), así como la induración en pruebas de intradermorreacción (p < 0.001). Se resolvieron las infecciones que se presentaron (4 %). No se reportaron efectos adversos. Conclusiones: El uso de EDL mejoró los parámetros inmunológicos y la evolución clínica en niños con déficit inmune celular.

Infection and coinfection by human papillomavirus, Epstein-Barr virus and Merkel cell polyomavirus in patients with squamous cell carcinoma of the larynx: a retrospective study.

BACKGROUND: Human papillomavirus (HPV) is recognized as an important risk factor for laryngeal carcinogenesis. Although HPV-16 and 18 have been strongly implicated, the presence of other high-risk HPV (HR-HPV) genotypes or the coinfection with Epstein-Barr virus (EBV) or Merkel cell polyomavirus (MCPV) may increase the risk, but their etiological association has not been definitively established. METHODS: We characterized the genotype-specific HPV and the frequency of EBV and MCPV infections through the detection of their DNA in 195 laryngeal specimens of squamous cell carcinoma (SCC) histologically confirmed. RESULTS: HPV DNA was detected in 93 (47.7%) specimens. HPV-11 was the most frequent with 68 cases (73.1%), and HPV-52 was the most frequently HR-HPV found with 51 cases, which corresponds to 54.8% of all HPV-positive specimens. EBV DNA was detected in 54 (27.7%) tumor tissue specimens of which 25 (46.3%) were in coinfection with HPV. MCPV DNA was detected only in 11 (5.6%) cases of which 5 (45.4%) were in coinfection with an HR-HPV. No association between the presence of DNA of the three examined viruses and the patient smoking habits, alcohol consumption, age, the keratinization status, differentiation grade, or localization of the tumor in the larynx were found. DISCUSSION: HPV-52 was the most prevalent HR-HPV, which may suggest that this and other genotypes in addition to HPV-16 and 18 could be considered for prophylaxis. However, further studies including non-cancer larynx cases and the evaluation of other molecular markers and viral co-infection mechanisms are needed to determine the role of the different HR-HPV genotypes, EBV, and MCPV in the etiology of SCC of the larynx.

In Vivo Chemoprotective Activity of Bovine Dialyzable Leukocyte Extract in Mouse Bone Marrow Cells against Damage Induced by 5-Fluorouracil.

Chemotherapy treatments induce a number of side effects, such as leukopenia neutropenia, peripheral erythropenia, and thrombocytopenia, affecting the quality of life for cancer patients. 5-Fluorouracil (5-FU) is wieldy used as myeloablative model in mice. The bovine dialyzable leukocyte extract (bDLE) or IMMUNEPOTENT CRP® (ICRP) is an immunomodulatory compound that has antioxidants and anti-inflammatory effects. In order to investigate the chemoprotection effect of ICRP on bone marrow cells in 5-FU treated mice, total bone marrow (BM) cell count, bone marrow colony forming units-granulocyte/macrophage (CFU-GM), cell cycle, immunophenotypification, ROS/superoxide and Nrf2 by flow cytometry, and histological and hematological analyses were performed. Our results demonstrated that ICRP increased BM cell count and CFU-GM number, arrested BM cells in G0/G1 phase, increased the percentage of leukocyte, granulocytic, and erythroid populations, reduced ROS/superoxide formation and Nrf2 activation, and also improved hematological levels and weight gain in 5-FU treated mice. These results suggest that ICRP has a chemoprotective effect against 5-FU in BM cells that can be used in cancer patients.

Expression of CCR5, CXCR4 and DC-SIGN in Cervix of HIV-1 Heterosexually Infected Mexican Women.

BACKGROUND: A number of studies have demonstrated that receptor and co-receptor expression levels which may affect viral entry, promoting cervical HIV infection. The aim was to evaluate the expression levels of CCR5, CXCR4and DC-SIGN mRNA in a sample of heterosexually HIV infected Mexican women. METHODS: We enrolled twenty-six HIV heterosexual infected women attending a local infectious diseases medical unit.RNA was isolated from the cervix and gene expression analysis was performed using real-time PCR. RESULTS: Expression rates for mRNA of CCR5 (median 1.82; range 0.003-2934) were higher than those observed for CXCR4 (0.79; 0.0061-3312) and DC-SIGN (0.33; 0.006-532) receptors (p < 0.05). A high correlation was found between the mRNA expression levels of these three receptors (rs = 0.52 to 0.85, p < 0.01). CONCLUSION: Levels of expression of the tested chemokine receptors in the cervix are different from each other and alsovary from woman to woman, and seem to support the suggestion that chemokine receptor expression in genital tissues may be playing a role in the HIV transmission.

Expression of DC-SIGN in peripheral blood dendritic cells of patients with typical, slow, and rapid progression to AIDS.

The main access route for human immunodeficiency virus (HIV) into the lymph nodes is through the mucosa. Once there, dendritic cells (DCs) are the first cells to interact with the virus. Then, DCs can uptake and transport to the lymph nodes, beginning a disseminated infection. Interaction between the virus and DCs is mediated by the receptor DC-SIGN. This study seeks to determine any relationship between HIV-AIDS immunopathology and DC-SIGN expression levels in DCs from typical, rapid, and slow progressors. A DC separation system was implemented using peripheral blood mononuclear cells from infected subjects. The study included 27 patients classified as typical, rapid, and slow progressors according to their clinical and epidemiological files. Finally, quantification of DC-SIGN was achieved by real-time PCR and by applying the Relative Quantification Scheme (DeltaDeltaCt). We isolated DCs from peripheral blood of 27 HIV-infected patients. Nineteen were considered as typical progressors, five as slow progressors, and three as rapid progressors. No significant differences were observed on the expression levels of DC-SIGN among the three groups of patients. Even if there are differences in expression levels among the analyzed patients, we did not find any significant differences in DC-SIGN expression among the three included groups. We therefore cannot conclude that the expression level of the receptor is related with the progression to AIDS.