Diagnosis of bacterial meningitis caused by Streptococcus pneumoniae, Neisseria meningitidis, and Haemophilus influenzae using a multiplex real-time PCR technique.

Bacterial meningitis is one of the diseases that, despite the introduction of several vaccines, remains a serious public health concern. Streptococcus pneumoniae (Spn), Neisseria meningitidis (Nm), and Haemophilus influenzae (Hi) are responsible for most cases diagnosed in children, adolescents, and adult population. Rapid, sensitive, and specific laboratory assays are critical for effective diagnosis and treatment, particularly in countries like Mexico in which culture positivity rates are very low due to the use of antibiotics prior to sample collection and to delay in transporting samples to the laboratory. The aim of this study was to evaluate the use of real-time polymerase chain reaction (RT-PCR) of cerebrospinal fluid (CSF) as a rapid diagnostic test for bacterial meningitis and compare these results with bacterial culture in three general hospitals in Mexico. During a 5-year period (2014-2018), a total of 512 CSF samples obtained from patients in whom infectious meningitis was suspected as initial clinical diagnosis were tested with RT-PCR with species-specific targets for the three pathogens. For Spn, 5.07% samples were RT-PCR positive; 0.39% for Nm and none for Hi. Only five RT-PCR Spn positive samples had a positive culture. Sensitivity and specificity estimates for RT-PCR are 100% and 95.46%, respectively. DNA amplification methods can provide better sensitive diagnostic tests than the reference standard, which is culture, particularly when antimicrobial treatment is initiated before clinical samples can be obtained.

An evaluation of multidrug-resistant Escherichia coli isolates in urinary tract infections from Aguascalientes, Mexico: cross-sectional study.

BACKGROUND: Uropathogenic Escherichia coli (UPEC) are one of the main bacteria causing urinary tract infections (UTIs). The rates of UPEC with high resistance towards antibiotics and multidrug-resistant bacteria have increased dramatically in recent years and could difficult the treatment. METHODS: The aim of the study was to determine multidrug-resistant bacteria, antibiotic resistance profile, virulence traits, and genetic background of 110 E. coli isolated from community (79 isolates) and hospital-acquired (31 isolates) urinary tract infections. The plasmid-mediated quinolone resistance genes presence was also investigated. A subset of 18 isolates with a quinolone-resistance phenotype was examined for common virulence genes encoded in diarrheagenic and extra-intestinal pathogenic E. coli by a specific E. coli microarray. RESULTS: Female children were the group most affected by UTIs, which were mainly community-acquired. Resistance to trimethoprim-sulfamethoxazole, ampicillin, and ampicillin-sulbactam was most prevalent. A frequent occurrence of resistance toward ciprofloxacin (47.3%), levofloxacin (43.6%) and cephalosporins (27.6%) was observed. In addition, 63% of the strains were multidrug-resistant (MDR). Almost all the fluoroquinolone (FQ)-resistant strains showed MDR-phenotype. Isolates from male patients were associated to FQ-resistant and MDR-phenotype. Moreover, hospital-acquired infections were correlated to third generation cephalosporin and nitrofurantoin resistance and the presence of kpsMTII gene. Overall, fimH (71.8%) and fyuA (68.2%), had the highest prevalence as virulence genes among isolates. However, the profile of virulence genes displayed a great diversity, which included the presence of genes related to diarrheagenic E. coli. Out of 110 isolates, 25 isolates (22.7%) were positive to qnrA, 23 (20.9%) to qnrB, 7 (6.4%) to qnrS1, 7 (6.4%) to aac(6')lb-cr, 5 (4.5%) to qnrD, and 1 (0.9%) to qnrC genes. A total of 12.7% of the isolates harbored blaCTX-M genes, with blaCTX-M-15 being the most prevalent. CONCLUSIONS: Urinary tract infection due to E. coli may be difficult to treat empirically due to high resistance to commonly used antibiotics. Continuous surveillance of multidrug resistant organisms and patterns of drug resistance are needed in order to prevent treatment failure and reduce selective pressure. These findings may help choosing more suitable treatments of UTI patients in this region of Mexico.

Presence of multi-drug resistant pathogenic Escherichia coli in the San Pedro River located in the State of Aguascalientes, Mexico.

Contamination of surface waters in developing countries is a great concern. Treated and untreated wastewaters have been discharged into rivers and streams, leading to possible waterborne infection outbreaks and may represent a significant dissemination mechanism of antibiotic resistance genes. In this study, the water quality of San Pedro River, the main river and pluvial collector of the Aguascalientes State, Mexico was assessed. Thirty sample locations were tested throughout the River. The main physicochemical parameters of water were evaluated. Results showed high levels of fecal pollution as well as inorganic and organic matter abundant enough to support the heterotrophic growth of microorganisms. These results indicate poor water quality in samples from different locations. One hundred and fifty Escherichia coli were collected and screened by PCR for several virulence genes. Isolates were classified as either pathogenic (n = 91) or commensal (n = 59). The disc diffusion method was used to determine antimicrobial susceptibility to 13 antibiotics. Fifty-two percent of the isolates were resistant to at least one antimicrobial agent and 30.6% were multi-resistant. Eighteen E. coli strains were quinolone resistant of which 16 were multi-resistant. Plasmid-mediated quinolone resistance (PMQR) genes were detected in 12 isolates. Mutations at the Ser-83→Leu and/or Asp-87→Asn in the gyrA gene were detected as well as mutations at the Ser-80→Ile in parC. An E. coli microarray (Maxivirulence V 3.1) was used to characterize the virulence and antimicrobial resistance genes profiles of the fluoroquinolone-resistant isolates. Antimicrobial resistance genes such as bla TEM, sulI, sulII, dhfrIX, aph3 (strA), and tet (B) as well as integrons were found in fluoroquinolone (FQ) resistance E. coli strains. The presence of potential pathogenic E. coli and antibiotic resistance in San Pedro River such as FQ resistant E. coli could pose a potential threat to human and animal health.

Phenotypes and genotypes of erythromycin-resistant Streptococcus pyogenes strains isolated from invasive and non-invasive infections from Mexico and the USA during 1999-2010.

OBJECTIVE: To compare the prevalence, phenotypes, and genes responsible for erythromycin resistance among Streptococcus pyogenes isolates from Mexico and the USA. METHODS: Eighty-nine invasive and 378 non-invasive isolates from Mexico, plus 148 invasive, 21 non-invasive, and five unclassified isolates from the USA were studied. Susceptibilities to penicillin, erythromycin, clindamycin, ceftriaxone, and vancomycin were evaluated according to Clinical and Laboratory Standards Institute (CLSI) standards. Phenotypes of erythromycin resistance were identified by triple disk test, and screening for mefA, ermTR, and ermB genes was carried out by PCR. RESULTS: All isolates were susceptible to penicillin, ceftriaxone, and vancomycin. Erythromycin resistance was found in 4.9% of Mexican strains and 5.2% of USA strains. Phenotypes in Mexican strains were 95% M and 5% cMLS; in strains from the USA, phenotypes were 33.3% iMLS, 33.3% iMLS-D, and 33.3% M. Erythromycin resistance genes in strains from Mexico were mefA (95%) and ermB (5%); USA strains harbored ermTR (56%), mefA (33%), and none (11%). In Mexico, all erythromycin-resistant strains were non-invasive, whereas 89% of strains from the USA were invasive. CONCLUSIONS: Erythromycin resistance continues to exist at low levels in both Mexico and the USA, although the genetic mechanisms responsible differ between the two nations. These genetic differences may be related to the invasive character of the S. pyogenes isolated.

Meningitis criptocócica tras tratamiento con etanercept / Cerebral cryptococcosis associated with etanercept

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[Systemic hypertension after kidney transplantation: associated risk factors and influence on graft survival]. / Hipertensión arterial postrasplante renal: factores de riesgo asociados e influencia en la supervivencia del injerto renal.

Systemic hypertension after kidney transplant (HAPT) has been associated with a reduction in graft survival and increased morbidity and mortality of kidney transplant recipients. With the use of calcinuerin inhibitors, prevalence of HAPT has increased to 60-80%. The purpose of this study was to document the prevalence of HAPT in kidney transplant recipients attending the Instituto Nacional de Ciencias Médicas y Nutrición "Salvador Zubirán" associated risk factors and the effect of hypertension in long term graft survival. We retrospectively reviewed the clinical charts of all the patients that underwent kidney transplant from 1984 to 1994. The following risk factors were studied: age, gender, cause of renal failure, presence of hypertension before kidney transplant, histocompatibility, acute rejection episodes, chronic rejection, serum creatinine values and use of cyclosporine. We divided subjects in two groups: normotensive (NT) and hypertensive (HT). HAPT included 3140/90 mmHg blood pressure level observed at least during two consecutive evaluations or the use of antihypertensive medication. We analyzed 215 grafts from 205 patients (10 patients had two kidney transplants); mean age at transplant of 30 +/- 9 years, 131 subjects were female and 84 male. One hundred and eighty eight patients (88%) displayed pretransplant hypertension. The mean follow up was 56+/-32 months. In the postransplant period 152 (71%) were HT and 63 (29%) NT. The HT group had significantly higher blood pressure and serum creatinine values than the NT group (P < 0.001), in spite of an adequate blood pressure control in 65% of the patients from the HT group. The NT group displayed a higher graft survival than the HT group; 60 +/- 30 months vs. 51 +/- 32 months respectively (p<0.01). Multivariate analysis did not show any risk factors independently associated with the development of HAPT. The prevalence of HAPT in our series is similar to the one reported in the literature. During the postransplant period there was a reduction of hypertensive patients (88% pretransplant vs. 71% postransplant). HAPT is a significant risk factor associated with long term survival of the graft.

Hipertensión arterial postrasplante renal: factores de riesgo asociados e influencia en la supervivencia del injerto renal / Systemic hypertension after kidney transplantation: Associated risk factors and influence on graft survival

La hipertensión arterial postrasplante renal (HAPT) se ha asociado con una disminución de la supervivencia del injerto renal y aumento de la morbilidad y mortalidad de los receptores de trasplante. La prevalencia de la HAPT es de 50% y con el uso de inhibidores de calcineurina se ha incrementado a 60-80%. Con el objeto de conocer la frecuencia de la HAPT en la población de pacientes del Instituto Nacional de Ciencias Médicas y Nutrición "Salvador Zubirán ", los factores de riesgo asociados a su desarrollo y el efecto de ésta en la supervivencia del injerto renal a largo plazo, se analizaron retrospec tivamente los expedientes de los pacientes sometidos a trasplante renal de 1984 a 1994. Los factores de riesgo analizados fueron: edad, género, causa de insuficiencia renal, hipertensión arterial pretrasplante, histocompatibilidad, presencia de episodios de rechazo agudo, presencia de rechazo crónico, creatinina sérica (CrS) y uso de Ciclosporina A. Se dividió a la población en dos grupos: normotensos (NT) e hipertensos (HT). Se definió HAPT como presión arterial (PA) > 140/90 mmHg por lo menos en dos visitas consecutivas o la utilización de tratamiento antihipertensivo. Se analizaron 215 seguimientos en 205 pacientes (10 pacientes con dos trasplantes), con edad al momento del trasplante de 30 ± 9 años y género masculino/femenino 131/84. Cursaron con hipertensión arterial pretrasplante 188 (88%). El seguimiento postrasplante promedio fue de 56 ± 32 meses. En el período postrasplante se encontraron 152 HT (71 %) y 63 (29%) NT. El grupo HT mostró una PA y CrS mayores que el grupo de NT (P <0.001) a pesar de contarse con un control antihipertensivo adecuado en 65% de los casos de HT. El grupo de NT tuvo mayor supervivencia del injerto que el grupo de HT, 60 ± 30 meses vs 51 ± 32 meses (p <0.01). El análisis multivariado de los diversos factores de riesgo estudiados no mostró alguna asociación independiente con el desarrollo de HAPT. La prevalencia de la HAPT en nuestro estudio es similar a lo informado en la literatura. En la etapa postrasplante disminuyó el porcentaje de pacientes hipertensos (88% pre vs 71% postrasplante). La presencia de HAPT constituye un factor de mal pronóstico para la supervivencia del injerto a largo plazo.

Systemic hypertension after kidney transplant (HAPT) has been associated with a reduction in graft survival and increased morbidity and mortalityof kidney transplant recipients. With the use of calcineurin inhibitors, prevalence of HAPT has increased to 60-80%. The purpose of this study was to document the prevalence of HAPT in kidney transplant recipients attending the Instituto Nacional de Ciencias Médicas y Nutrición "Salvador Zubirán" associated risk factors and the effect of hypertension in long term graft survival. We retrospectively reviewed the clinical charts of all the patients that underwent kidney transplant from 1984 to 1994. The following risk factors were studied: age, gender, cause of renal failure, presence of hypertension before kidney transplant, histocompatibility, acute rejection episodes, chronic rejection, serum creatinine values and use of cyclosporine. We divided subjects in two groups: normotensive (NT) and hypertensive (HT). HAPT included >140/90 mmHg blood pressure level observed at least during two consecutive evaluations or the use of antihypertensive medication. We analyzed 215 grafts from 205 patients (10 patients had two kidney transplants); mean age at transplant of 30 ± 9 years, 131 subjects were female and 84 male. One hundred and eighty eight patients (88%) displayed pretransplant hypertension. The mean follow up was 56± 32 months. In the postransplant period 152 (71 %) were HT and 63 (29%) NT. The HT group had significantly higher blood pressure and serum creatinine values than the NT group (P <0.001), in spite of an adequate blood pressure control in 65% of the patients from the HT group. The NT group displayed a higher graft survival than the HT group; 60 ± 30 months vs. 51 ± 32 months respectively (p<0.01). Multivariate analysis did not show any risk factors independently associated with the development of HAPT. The prevalence of HAPT in our series is similar to the one reported in the literature. During the postransplant period there was a reduction of hypertensive patients (88% pretransplant vs. 71% postransplant). HAPT is a significant risk factor associated with long term survival of the graft.