Search

There are significant ethnic differences in the metabolism of some drugs that can be explained by cytochrome P450 polymorphisms and, in particular, the CYP2D6 isozyme. In addition, among patients who are not carriers of the CYP2C19 loss-of-function alleles, there is a reduced risk of stroke when clopidogrel is taken with aspirin compared to aspirin alone. These findings demonstrate that there is inter-ethnic variability in the metabolism of some drugs, which results in different responses to cardiovascular drugs in Asian versus non-Asian populations.

The aim of this study was to determine the bacteriological quality of bottled water samples obtained from small purification plants located in Mexico City and to identify potentially pathogenic nontuberculous mycobacteria (NTM) species found in these samples. All 111 samples analyzed were positive for aerobic mesophilic bacteria (AMB) and 46 (41.4%) did not comply with Mexico's Official Guidelines. Sixty-nine (62.1%) and 23 (20.7%) water samples were positive for total coliforms (TC) and fecal coliforms (FC), respectively. A total of 81 (72.9%) of the water samples exceeded the maximum allowed limit stipulated in the guideline. Thirty-three (29.7%) of the purified water samples were positive for NTM, being recovered a total of 40 isolates. These NTM isolates were identified using three molecular markers (hsp65, rrs and rpoB genes) which corresponded to the fast-growing mycobacteria M. chelonae (n = 12), M. porcinum (n = 8), M. senegalense (n = 5), M. abscessus (n = 4), M. septicum (n = 4), M. wolinskyi (n = 3), M. mucogenicum (n = 2), M. fortuitum (n = 1) and M. sp. (n = 1). In seven purified water samples, two different NTM species were isolated simultaneously. Overall, these results showed that most of the purified bottled water samples analyzed in this study had unsatisfactory microbiological quality and some harbored NTM associated with illness. Our data could hasten health authorities to intensify efforts in the routine monitoring of activities in the purified bottled water industry in order to supply safe and healthy water to the public., (Copyright © 2019 Elsevier B.V. All rights reserved.)

The aims of this study were to evaluate the microbiological quality and the occurrence of nontuberculous mycobacteria (NTM) in a variety of salads and sprouts from supermarkets and street vendors in Mexico City. Aerobic-mesophilic bacteria (AMB) were present in 100% of RTE-salads samples; 59% of samples were outside guidelines range (>5.17 log10 CFU per g). Although fecal coliforms (FC) were present in 32% of samples, only 8% of them exceeded the permissible limit (100 MPN/g). Regarding the 100 RTE-sprouts, all samples were also positive for AMB and total coliforms (TC) and 69% for FC. Seven NTM species were recovered from 7 salad samples; they included three M. fortuitum, two M. chelonae, one M. mucogenicum, and one M. sp. Twelve RTE-sprouts samples harbored NTM, which were identified as M. porcinum (five), M. abscessus (two), M. gordonae (two), M. mucogenicum (two), and M. avium complex (one). Most RTE-salads and RTE-sprouts had unsatisfactory microbiological quality and some harbored NTM associated with illness. No correlation between the presence of coliforms and NTM was found. Overall, these results suggest that RTE-salads and RTE-sprouts might function as vehicles for NTM transmission in humans; hence, proper handling and treatment before consumption of such products might be recommendable.

Consumption of ready-to-eat (RTE) salads has increased worldwide. Consequently, the number of outbreaks caused by food-borne pathogens, including diarrheagenic E. coli pathotypes (DEPs), associated with the consumption of RTE-salads has increased. DEPs include enterotoxigenic (ETEC), typical and atypical enteropathogenic (tEPEC, aEPEC), enteroinvasive (EIEC), enteroaggregative (EAEC), diffuse adherent (DAEC) and Shiga toxin-producing (STEC) E. coli. In less-developed areas of the world, fresh crops continue to be irrigated with untreated sewage water. The aims of this study were to evaluate the microbiological quality and prevalence of DEPs in RTE-salads of raw vegetables, purchased from restaurants at Pachuca-City, Hidalgo, Mexico, where most locally consumed vegetables are irrigated with untreated sewage water. A total of 130 salads were purchased from restaurants of three categories: A) national chain restaurants and B) local restaurants, both with the H distinctive (a recognition that the Secretary of Tourism grants to restaurants that manage supplies with high levels of hygiene); and C) local small inexpensive restaurants without H distinctive. A total of 6 restaurants were included, 2 per category (A(1-2), B(1-2), C(1-2)). Each sample was tested for the presence of faecal coliforms (FC) and E. coli by standard procedures. E. coli strains were further characterized for the presence of DEPs loci by two multiplex polymerase chain reactions. Among the 130 salad samples 99% (129) were contaminated with FC; 85% (110/129) harboured E. coli and 7% (8/110) DEPs. The amount of positive salad samples for FC and E. coli was similar between restaurants and categories. The FC mean (571 FC/g) of all samples was significantly higher (p<0.001) than the E. coli mean (63 E. coli/g). A weak correlation of 7.7% (r(2)=0.077, p=0.003) between median FC and E. coli MPN (most probable number) per sample was found. Of the 8 salad samples contaminated with DEPs, 2 were spinach salads from restaurant A(2) and 3 were (Mixed salad) samples from each C restaurant. Three samples harboured non-O157 STEC strains, 2 EIEC, 1 ETEC and 2 samples had non-O157 STEC and EIEC strains, simultaneously. A significant difference (p=0.008) between the prevalence of E. coli vs. DEPs was observed. Independently of the restaurants' overall hygienic status, most RTE-salads had a poor microbiological quality and some harboured DEPs that have been associated with illness in Mexico. Health authorities should focus on implementing DEPs screening in raw vegetables and enforcing the legislation that forbids irrigation with untreated sewage water of both root and leafy vegetables., (Copyright © 2012 Elsevier B.V. All rights reserved.)

Seventy-six children < or =2 years old were prospectively followed for 1 year in a peri-urban community of Mexico City to determine asymptomatic infection and acute diarrhea associated with diarrheagenic Escherichia coli pathotypes (DEPs). By use of a pathogen-specific multiplex PCR, DEPs were sought in 795 stool samples, of which 125 (16%) were positive for DEP; of these, 4 represented shedding episodes and 4 parasite coinfections. Most single-DEP infections (85/117) were asymptomatic (P < 0.001), and of the 32 DEP diarrhea episodes, 41% were associated with atypical enteropathogenic E. coli (aEPEC), 37.5% with enterotoxigenic E. coli, 9% with typical EPEC, 9% with enteroinvasive E. coli, and 3% with Shiga toxin-producing E. coli strains. Among the 76 children, 54 had at least one stool positive for DEP, of which 23 experienced a DEP-associated diarrhea episode. In the last group of children, DEP infection was significantly associated with a diarrhea episode (relative risk [RR] = 2.5; 95% confidence interval [CI], 1.79 to 3.57; P < 0.001), with ETEC (RR = 2.30; 95% CI, 1.49 to 3.54; P = 0.003) and aEPEC (RR = 1.92; 95% CI, 1.23 to 3.0; P = 0.019) being the pathotypes associated with diarrhea. aEPEC-associated diarrhea episodes were frequently in the <12-month age group (RR = 2.57; 95% CI, 1.05 to 6.27; P = 0.04). aEPEC infections were distributed all year round, but associated diarrheal episodes were identified from April to October, with a May-June peak (rainy season). Most ETEC infections and diarrhea episodes characteristically occurred during the summer (rainy season), with a diarrhea peak in August. Of all DEPs, only aEPEC was associated with acute diarrhea episodes lasting 7 to 12 days (P = 0.019). DEPs are important causes of community-acquired enteric infection and diarrhea in Mexican children.