Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “MEXICO”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 901 records · Page 50Linked to original sources
PubMed1986

Dental caries status of young children in a suburban community of Mexico City.

One hundred and thirty-four children, 6 to 7 yr of age from a public school in Tepepan, Mexico were examined for the prevalence and severity of dental caries. Average deft score was 6.08 and defs was 12.15. Average DMFT and DMFS scores were .57 and .99 respectively. It was observed that 66% of primary teeth with carious lesions required one surface restoration and 11% three or more surface restorations. In the permanent dentition 99% of the affected teeth required one surface restoration. A comparison of the results with those of the Mexico City public school children survey (1980) showed that the Tepepan children had a similar caries level in primary teeth and a lower caries level in permanent teeth. Although the Tepepan group showed fewer carious lesions, their caries index and unmet restorative index are still high, especially for primary dentition, so an intensive educational, preventive and restorative program is required.

Child↗
PubMed1991

Dental caries and mutans streptococci in selected groups of urban and native Indian schoolchildren in Mexico.

Two groups of Mexican children aged 12-14 yr were examined for dental caries and salivary mutans streptococci counts. One hundred lived in Mexico City and 100 belonged to a native Mazahua Indian population. The prevalence of caries, diagnosed according to WHO, was 90% in Mexico City and 82% in the Indian community. Mean DMFT was 5.98 and 3.57 respectively. Saliva samples were analyzed for mutans streptococci by the "Strip mutans" method. Further identification of the biotype/serotype was done. Mutans streptococci were found in 95% of the urban children and 75% of the Indians. There was a statistically significant difference in the prevalence of mutans streptococci between the city and the rural samples. Streptococcus mutans was more frequently found than Streptococcus sobrinus.

Adolescent↗
PubMedDate not supplied

Revisiting a classification scheme for U.S.-Mexico alluvial basin-fill aquifers.

Intermontane basins in the Trans-Pecos region of westernmost Texas and northern Chihuahua, Mexico, are target areas for disposal of interstate municipal sludge and have been identified as possible disposal sites for low-level radioactive waste. Understanding ground water movement within and between these basins is needed to assess potential contaminant fate and movement. Four associated basin aquifers are evaluated and classified; the Red Light Draw Aquifer, the Northwest Eagle Flat Aquifer, the Southeast Eagle Flat Aquifer, and the El Cuervo Aquifer. Encompassed on all but one side by mountains and local divides, the Red Light Draw Aquifer has the Rio Grande as an outlet for both surface drainage and ground water discharge. The river juxtaposed against its southern edge, the basin is classified as a topographically open, through-flowing basin. The Northwest Eagle Flat Aquifer is classified as a topographically closed and drained basin because surface drainage is to the interior of the basin and ground water discharge occurs by interbasin ground water flow. Mountains and ground water divides encompass this basin aquifer on all sides; yet, depth to ground water in the interior of the basin is commonly >500 feet. Negligible ground water discharge within the basin indicates that ground water discharges from the basin by vertical flow and underflow to a surrounding basin or basins. The most likely mode of discharge is by vertical, cross-formational flow to underlying Permian rocks that are more porous and permeable and subsequent flow along regional flowpaths beneath local ground water divides. The Southeast Eagle Flat Aquifer is classified as a topographically open and drained basin because surface drainage and ground water discharge are to the adjacent Wildhorse Flat area. Opposite the Eagle Flat and Red Light Draw aquifers is the El Cuervo Aquifer of northern Chihuahua, Mexico. The El Cuervo Aquifer has interior drainage to Laguna El Cuervo, which is a phreatic playa that also serves as a focal point of ground water discharge. Our evidence suggests that El Cuervo Aquifer may lose a smaller portion of its discharge by interbasin ground water flow to Indian Hot Springs, near the Rio Grande. Thus, El Cuervo Aquifer is a topographically closed basin that is either partially drained if a component of its ground water discharge reaches Indian Hot Springs or undrained if all its natural ground water discharge is to Laguna El Cuervo.

Classification↗
PubMed1987

The New Mexico sealant program: a progress report.

In 1979, the dental health program of the New Mexico Health and Environment Department began a school-based sealant activity. Children in the first, second, third, sixth, and seventh grades in selected New Mexico communities were offered sealants through this sealant activity. During the 1984-85 school year, program staff began seeing several hundred sixth-grade students who had received sealants in either the first, second, or third grade. Tooth- and surface-specific data on the current condition of all the previously sealed occlusal surfaces were collected from all these previous recipients of sealants. During the 1985-86 school year, we found that sixth-grade students who received sealants as first, second, or third graders had 5.6 percent of the occlusal surfaces of their first permanent molars either decayed, missing, or filled. Their classmates who had not previously received sealants had 26.85 percent of the same tooth surfaces either decayed, missing, or filled. During the 1985-86 school year, the complete retention rates for sealants were found to be 67.36 percent after six years, 78.53 percent after five years, and 93.47 percent after one year. The partial retention rates were found to be 10.46 percent after six years, 10.63 percent after five years, and 3.04 percent after one year.

Child↗
PubMed2004

Nutrition transition in Mexico and in other Latin American countries.

Mexico and other Latin American countries are currently undergoing important demographic, epidemiologic and nutrition transitions. Noncommunicable chronic diseases such as obesity, type 2 diabetes mellitus, and high blood pressure are becoming public health problems as the population experiences an important reduction in physical activity and an increase in energy-dense diets. In contrast, the prevalence of undernutrition is declining in most countries, although several decades will be needed before the prevalence drops to acceptable values. The objective of this article is to discuss the characteristics of the nutrition transition with emphasis in data from Mexico, Brazil, and Chile.

Chronic Disease↗
PubMed1998

Knowledge and opinions about dental human health resources planning in Mexico.

Dental human health resource planning (DHHRP), or manpower planning in Mexico has been plagued by fundamental contradictions. In spite of having trained a great many dentists in the past two decades, the dental health status of the population has not significantly improved. Concurrently, the relative scarcity of patients in relation to the number of practising dentists seems to be more marked, a critical issue since most dental care is delivered under private schemes. In the present investigation, 196 practising dentists in Mexico City were interviewed to establish their knowledge and opinions about DHHRP, and their views about the introduction of innovative alternatives in transforming, evaluating and planning human health resources. Concerns were: a need to examine and re-define the aims, skill content and marketability of professional training in professional practice; a lack of consensus as to how this is to be achieved; and a degree of awareness that professional practice has a limited scope in meeting the challenge of providing adequate care because of maldistribution of dentists and of limited financial resources of patients.

Adult↗
PubMedDate not supplied

Isolation of Cryptococcus neoformans from pigeon (Columba livia) droppings in Mexico City.

To determine the ecological and epidemiological significance of pigeon excrement in cryptococcosis in Mexico City, 251 samples of pigeon droppings were studied. These were collected from houses, public buildings, churches, parks and pigeon nests. Each sample was suspended 1:10 in isotonic saline solution and then cultured in Staib medium. Identification of Cryptococcus neoformans was performed based on the development of brown-coloured colonies and the presence of encapsulated yeasts. Of 251 samples, 52 (20.7%) were positive for Cr. neoformans. The highest frequency was observed in droppings from public buildings (31.2%), followed by churches (22.0%) and houses (13.3%). No significant differences in isolation frequency were observed between fresh or dried excrement. All isolates obtained were Cr. neoformans var. neoformans. As in other studies on Cr. neoformans from pigeons, performed in other countries, these frequency data are considered 'normal'. The results, however, accentuate the potential risk of cryptococcosis acquisition, especially now that cryptococcosis frequency is increasing in Mexico, mainly in AIDS patients.

Animals↗
PubMed1973

Salmonella typhi resistant to chloramphenicol, ampicillin, and other antimicrobial agents: strains isolated during an extensive typhoid fever epidemic in Mexico.

During 1972 a large epidemic, in excess of 10,000 cases, of typhoid fever occurred in Mexico City, Pachuca, and other communities of Mexico. The main characteristic of the epidemic, in addition to the large number of persons affected, was the prevalence of a strain of Salmonella typhi which was highly resistant to chloramphenicol both in vivo and in vitro, and which belonged to a single phage type, Vi degraded approaching type A. Of 493 strains of S. typhi studied during the outbreak, 452 (91.7%) were resistant to chloramphenicol (CM), tetracycline (TC), streptomycin (SM), and sulfonamides (SU). The epidemic strain owes its resistance to an R factor which is easily transferable to Escherichia coli K-12 and which appears to be stable. In the third month of the outbreak, a strain of S. typhi resistant to CM, TC, SM, SU, ampicillin (AM), and kanamycin (KM) was isolated from a patient with severe typhoid fever. During the following 9 months, six additional strains of S. typhi resistant to AM, CM, TC, SM, and SU were also isolated. Transfer experiments to E. coli K-12 indicate that these strains are infected with two different R factors, one causing CM, TC, SM, and SU resistance and the other causing AM or AM and KM resistance. The frequency of transfer of the resistance in overnight crosses was in the order of 10(-4) for CM, TC, SM, and SU and 10(-6) for AM or AM, and KM. The appearance of these strains resistant both to chloramphenicol and ampicillin was a cause for concern for the clinicians; fortunately, they have remained an infrequent cause of disease.

Ampicillin↗
PubMed2006

Quantitative detection of hepatitis a virus and enteroviruses near the United States-Mexico border and correlation with levels of fecal indicator bacteria.

For decades, untreated sewage flowing northward from Tijuana, Mexico, via the Tijuana River has adversely affected the water quality of the recreational beaches of San Diego, California. We used quantitative reverse transcription-PCR to measure the levels of hepatitis A virus (HAV) and enteroviruses in coastal waters near the United States-Mexico border and compared these levels to those of the conventional fecal indicators, Escherichia coli and enterococci. Over a 2-year period from 2003 to 2005, a total of 20 samples were assayed at two sites during both wet and dry weather: the surfzone at the mouth of the Tijuana River and the surfzone near the pier at Imperial Beach (IB), California (about 2 km north of the mouth of the Tijuana River). HAV and enterovirus were detected in 79 and 93% of the wet-weather samples, respectively. HAV concentrations in these samples ranged from 105 to 30,771 viral particles/liter, and enterovirus levels ranged from 7 to 4,417 viral particles/liter. The concentrations of HAV and enterovirus were below the limit of detection for all dry weather samples collected at IB. Regression analyses showed a significant correlation between the densities of both fecal bacterial indicators and the levels of HAV (R2>0.61, P<0.0001) and enterovirus (R2>0.70, P<0.0001), a finding that supports the use of conventional bacterial indicators to predict the levels of these viruses in recreational marine waters.

Base Sequence↗
PubMed2006

Recovery of Mycobacterium bovis from soft fresh cheese originating in Mexico.

Recent outbreaks of human tuberculosis in the United States caused by Mycobacterium bovis have implicated cheese originating in Mexico as a source of these infections. A total of 203 samples of cheese originating in Mexico were cultured, and M. bovis was recovered from one specimen. Therefore, M. bovis can be recovered from cheese and may be a source of human infections.

Animals↗
PubMed2004

Identification of members of the metabolically active microbial populations associated with Beggiatoa species mat communities from Gulf of Mexico cold-seep sediments.

In this study, the composition of the metabolically active fraction of the microbial community occurring in Gulf of Mexico marine sediments (water depth, 550 to 575 m) with overlying filamentous bacterial mats was determined. The mats were mainly composed of either orange- or white-pigmented Beggiatoa spp. Complementary 16S ribosomal DNA (crDNA) was obtained from rRNA extracted from three different sediment depths (0 to 2, 6 to 8, and 10 to 12 cm) that had been subjected to reverse transcription-PCR amplification. Domain-specific 16S PCR primers were used to construct 12 different 16S crDNA libraries containing 333 Archaea and 329 Bacteria clones. Analysis of the Archaea clones indicated that all sediment depths associated with overlying orange- and white-pigmented microbial mats were almost exclusively dominated by ANME-2 (95% of total Archaea clones), a lineage related to the methanogenic order Methanosarcinales. In contrast, bacterial diversity was considerably higher, with the dominant phylotype varying by sediment depth. An equivalent number of clones detected at 0 to 2 cm, representing a total of 93%, were related to the gamma and delta classes of Proteobacteria, whereas clones related to delta-Proteobacteria dominated the metabolically active fraction of the bacterial community occurring at 6 to 8 cm (79%) and 10 to 12 cm (85%). This is the first phylogenetics-based evaluation of the presumptive metabolically active fraction of the Bacteria and Archaea community structure investigated along a sediment depth profile in the northern Gulf of Mexico, a hydrocarbon-rich cold-seep region.

Base Sequence↗
PubMed2005

Longitudinal study of microbial diversity and seasonality in the Mexico City metropolitan area water supply system.

In the Mexico City metropolitan area (MCMA), 70% of the water for 18 million inhabitants is derived from the Basin of Mexico regional aquifer. To provide an overview of the quality of the groundwater, a longitudinal study was conducted, in which 30 sites were randomly selected from 1,575 registered extraction wells. Samples were taken before and after chlorine disinfection during both the rainy and dry seasons (2000-2001). Microbiological parameters (total coliforms, fecal coliforms, streptococci, and Vibrio spp.), the presence of Helicobacter pylori, and physicochemical parameters, including the amount of trihalomethanes (THMs), were determined. Although microorganisms and inorganic and organic compounds were evident, they did not exceed current permissible limits. Chlorine levels were low, and the bacterial counts were not affected by chlorine disinfection. Eighty-four bacterial species from nine genera normally associated with fecal contamination were identified in water samples. H. pylori was detected in at least 10% of the studied samples. About 40% of the samples surpassed the THM concentration allowed by Mexican and U.S. regulations, with levels of chloroform being high. The quality of the water distributed to the MCMA varied between the rainy and dry seasons, with higher levels of pH, nitrates, chloroform, bromodichloromethane, total organic carbon, and fecal streptococci during the dry season. This study showed that the groundwater distribution system is susceptible to contamination and that there is a need for a strict, year-round disinfection strategy to ensure adequate drinking-water quality. This situation in one of the world's megacities may reflect what is happening in large urban centers in developing countries which rely on a groundwater supply.

Bacteria↗
PubMed1987

Enteroadherent Escherichia coli as a cause of diarrhea among children in Mexico.

Enteropathogenic Escherichia coli (EPEC) often exhibits localized adherence or diffuse adherence to HEp-2 cells. We recently provided evidence that HEp-2 cell-adherent or enteroadherent E. coli (EAEC) not belonging to EPEC serogroups was the cause of diarrhea among U.S. travelers to Mexico. In the present study, we looked for EAEC and EPEC in stool specimens from 154 children with acute diarrhea and 137 well children seen at several outpatient clinics in Guadalajara, Mexico. EAEC showing localized adherence (EAEC-L) was isolated from 13.0% of the patients and 0.7% of the controls (P less than 0.0001). EAEC showing diffuse adherence (EAEC-D) was recovered from 20.8% of the patients and 7.3% of the controls (P less than 0.001). EPEC was isolated from 4.5 and 6.7% of the patients and controls, respectively. Among all enteropathogens, only enterotoxigenic E. coli occurred as commonly (21.4%) as EAEC-D and EAEC-L did in children with diarrhea. Of the EAEC-L strains isolated from children with diarrhea, 20% belonged to recognized EPEC serogroups, and 3.1% of EAEC-D strains belonged to recognized EPEC serogroups. This study suggests that EAEC may be an important pediatric enteropathogen in Mexican children with diarrhea and further supports the observation that adherence to HEp-2 cells may be a marker of virulence independent of EPEC serogroup among E. coli strains.

Bacterial Adhesion↗
PubMed2001

Luciferase reporter mycobacteriophages for detection, identification, and antibiotic susceptibility testing of Mycobacterium tuberculosis in Mexico.

The utility of luciferase reporter mycobacteriophages (LRPs) for detection, identification, and antibiotic susceptibility testing of Mycobacterium tuberculosis was prospectively evaluated in a clinical microbiology laboratory in Mexico City, Mexico. Five hundred twenty-three consecutive sputum samples submitted to the laboratory during a 5-month period were included in this study. These specimens were cultivated in Middlebrook 7H9 (MADC), MGIT, and Löwenstein-Jensen (LJ) media. Of the 71 mycobacterial isolates recovered with any of the three media, 76% were detected with the LRPs, 97% were detected with the MGIT 960 method, and 90% were detected with LJ medium. When contaminated specimens were excluded from the analysis, the LRPs detected 92% (54 of 59) of the cultures. The median time to detection of bacteria was 7 days with both the LRPs and the MGIT 960 method. LRP detection of growth in the presence of p-nitro-alpha-acetylamino-beta-hydroxypropiophenone (NAP) was used for selective identification of M. tuberculosis complex (MTC) and compared to identification with BACTEC 460. Using the LRP NAP test, 47 (94%) out of 50 isolates were correctly identified as tuberculosis complex. The accuracy and speed of LRP antibiotic susceptibility testing with rifampin, streptomycin, isoniazid, and ethambutol were compared to those of the BACTEC 460 method, and discrepant results were checked by the conventional proportion method. In total, 50 MTC isolates were tested. The overall agreement between the LRP and BACTEC 460 results was 98.5%. The median LRP-based susceptibility turnaround time was 2 days (range, 2 to 4 days) compared to 10.5 days (range, 7 to 16 days) by the BACTEC 460 method. Phage resistance was not detected in any of the 243 MTC isolates tested. Mycobacteriophage-based approaches to tuberculosis diagnostics can be implemented in clinical laboratories with sensitivity, specificity, and rapidity that compare favorably with those of the MGIT 960 and BACTEC 460 methods. The phages currently provide the fastest phenotypic assay for susceptibility testing.

Antitubercular Agents↗
PubMed2003

Unexpected detection of animal VP7 genes among common rotavirus strains isolated from children in Mexico.

In the course of characterizing 103 rotaviruses from children in Mexico, we found that the majority of strains were globally common types (55.4% of total), while uncommon types represented 5.7%, mixed infections with common types represented 14.8%, and partially or fully nontypeable isolates represented about 24%. Serotype G9 was detected for the first time in Mexico. We sequenced a subset of strains that were G nontypeable by reverse transcriptase PCR and found surprisingly that two strains having common human rotavirus P genotypes (8 and 6) had serotype G3 and G4 VP7 gene sequences that shared closer homology with canine and porcine strains, respectively, than with human strains, suggesting that these isolates represented reassortants between human and animal rotaviruses.

Animals↗
PubMed2004

Surveillance of methicillin-resistant Staphylococcus aureus in a pediatric hospital in Mexico City during a 7-year period (1997 to 2003): clonal evolution and impact of infection control.

Between 1997 and 2000 a single multidrug-susceptible methicillin-resistant Staphylococcus aureus clone, M (sequence type 30 [ST30]-staphylococcal cassette chromosome mec [SCCmec] type IV), was present in a pediatric hospital in Mexico City, Mexico. In 2001 the international multidrug-resistant New York-Japan clone (ST5-SCCmec type II) was introduced into the hospital, completely replacing clone M by 2002.

Child↗
PubMed2005

Prevalence of norovirus among visitors from the United States to Mexico and Guatemala who experience traveler's diarrhea.

Traveler's diarrhea (TD) is the most common infectious illness acquired by visitors to developing nations. The purpose of this study was to utilize molecular diagnostic techniques to determine the prevalence of norovirus (NoV) in TD occurring among visitors from the United States to Guatemala and Mexico. Stool samples (n = 54) were collected from 34 TD cases and analyzed for NoV by reverse transcription-PCR and oligoprobe confirmation. The overall prevalence of NoV was 65%. Interestingly, all NoV-positive stool samples were identified as genogroup I NoVs, and time spent at travel destinations was found to be an important factor in determining the frequency of infection (P = 0.003). Eleven NoV-positive stool samples also tested positive for enterotoxigenic Escherichia coli, indicating that dual infections with this leading bacterial cause of TD were very common. Results of this study suggest that NoV infection is a frequent occurrence among travelers to Mexico and Guatemala who experience episodes of TD. In addition, the simple molecular detection method utilized here will serve to facilitate more in-depth epidemiological studies of this emergent viral pathogen in travelers and other at-risk populations.

Blotting, Southern↗
PubMed1977

Canine brucellosis: bacteriological and serological investigation of naturally infected dogs in Mexico City.

Bacteriological investigation of canine brucellosis in Mexico City revealed a high rate (11.8%) of Brucella canis infection in a sampling of 59 stray dogs. When conservative criteria were employed in the interpretation of serological test results, there was general agreement between the serological and bacteriological findings; however, some animals with localized male genital tract infections could not be judged as infected solely by serological tests. All Mexican field isolates were identified as B. canis; however, some diversity was observed as regards nitrate reduction, growth in the presence of basic fuchsine, and the degree of mucoidness. The seemingly high prevalence of B. canis infection in Mexico City dogs suggests the need for further inquiry into the possible public health significance.

Agglutination Tests↗