Association of phylogenetic distribution and presence of integrons with multidrug resistance in Escherichia coli clinical isolates from children with diarrhoea.

BACKGROUND: Escherichia coli strains include both commensal and virulent clones distributed in different phylogenetic groups. Antimicrobial resistance is an increasingly serious public health threat at the global level and integrons are important mobile genetic elements involved in resistance dissemination. This paper aims to determine the phylogenetic groups and presence of class 1 (intl1) and 2 (intl2) integrons in E. coli clinical isolates from children with diarrhoea, and to associate these characteristics with their antimicrobial resistance. METHODS: Phylogeny and presence of integrons (intl1 and intl2) were analysed by PCR and amplicon sequencing in 70 E. coli isolates from children with and without diarrhoea (35 of each group) from Sinaloa, Mexico; these variables were analysed for correlation with the antimicrobial resistance profile of the isolates. RESULTS: The most frequent phylogroups were A (42.9%) and B2 (15.7%). The E. coli isolates from children with diarrhoea were distributed in all phylogroups; while strains from children without diarrhoea were absent from phylogroups C, E, and clade I. The 17.1% of the isolates carried integrons (15.7% intI1 and 1.4% intI2); 28.6% of the isolates from children with diarrhoea showed the class 1 integron. Strains of phylogroup A showed the highest frequency of integrons (33.3%). The association of multidrug resistance and the presence of integrons was identified in 58.3% of strains isolated from children with diarrhoea included in phylogroups A and B2. The sequence analysis of intl1 and intl2 showed silent point mutations and similarities with plasmids of some APEC and AIEC strains. CONCLUSION: Commensal E. coli strains are potential disseminators of antimicrobial resistance, and the improvement in the use of antimicrobials to treat childhood diarrhoea is essential for the control of such resistance.

Draft genome sequence of Escherichia coli M51-3: a multidrug-resistant strain assigned as ST131-H30 recovered from infant diarrheal infection in Mexico.

OBJECTIVES: In this study, we report the draft genome sequence of a multidrug-resistant (MDR)Escherichia coli strain recovered from stool sample of an outpatient infant girl with acute diarrheal infection in Mexico. METHODS: Antimicrobial susceptibility testing and PCR-based detection of diarrheagenic E. coli (DEC) were performed. In addition, genomic DNA from E. coli strain M51-3 was sequenced using Ion Torrent PGM platform with 200-bp chemistry and generated reads were de novo assembled using SPAdes v3.11. The draft genome was annotated and analyzed regarding multilocus sequence typing (MLST), serotyping, fimH typing, plasmid replicons, acquired antimicrobial resistance and virulence genes using web tools available at the Center for Genomic Epidemiology. RESULTS: A draft genome comprising 5 088 545 bp in length and 5308 protein-coding sequences was generated. In silico typification revealed that E. coli strain M51-3 belongs to ST131-O25:H4-H30 pandemic subclone. Several genes associated with resistance to ß-lactams [blaTEM-1B], aminoglycosides [aph(3'')-Ib, aadA5, aph(6)-Id and aac(3)-IId], sulfonamides [sul1 and sul2], trimethoprim [dfrA17], and tetracycline [tet(A)] were identified. Besides, point mutations in gyrA, parC, and parE genes were detected. Interestingly, the enterotoxin-coding virulence gene senB was evidenced. CONCLUSIONS: To our knowledge, this is the first draft genome of an E. coli ST131-O25:H4-H30 strain recovered from infant diarrheal stool sample in Mexico. The genome sequence of E. coli M51-3 presented here will be helpful to understand the genomic diversity of this highly virulent and MDR successfully pandemic bacterial pathogen.

Whole-genome sequencing of Staphylococcus aureus L401, a mecA-negative community-associated methicillin-resistant strain isolated from a healthy carrier.

OBJECTIVES: Methicillin-resistant Staphylococcus aureus (MRSA) is a human pathogen of great concern owing to its antimicrobial resistance and virulence properties. Here we report the first draft genome sequence of a mecA-negative community-associated MRSA strain isolated from a healthy young Mexican paediatric carrier in order to reveal the genomic structure underlying the multidrug-resistant phenotype and to discover the virulence properties of this strain. METHODS: The draft genome sequence of S. aureus L401 was obtained using an Ion Torrent™ PGM platform. De novo assembled contigs were annotated, and antimicrobial resistance genes and virulence factors were identified using ResFinder and VirulenceFinder, respectively. In addition, a mutational survey of native pbp, gdpP and yjbH genes was performed. In silico multilocus sequence typing (MLST) and spa typing were also performed. RESULTS: S. aureus L401 has a genome size of 2 831 587 bp with 2799 protein-coding sequences. Various antimicrobial resistance genes conferring resistance to aminoglycosides, ß-lactams, fluoroquinolones and macrolide-lincosamide-streptogramin B antimicrobials were found. Although both mecA and staphylococcal cassette chromosome mec (SCCmec) elements were absent, a missense mutation in PBP3 was identified. Moreover, genes encoding exfoliative toxin A, γ- and ß-haemolysin, and several enterotoxins were also identified. S. aureus L401 belongs to ST109 and spa type t209. CONCLUSION: The availability of this genome will allow an insight into S. aureus resistance and virulence determinants as well as its epidemiology, lineage, evolution and genomic features involved in the paediatric commensal carriage.

The development of the Mexican Familial Hypercholesterolemia (FH) National Registry.

BACKGROUND AND AIMS: In Mexico, familial hypercholesterolemia (FH) is, as in other parts of the world, largely underdiagnosed and undertreated, and represents a significant burden to the healthcare system. However, there is not enough information to design public policies against the disease. Genetic studies have shown that LDLR mutations are the most common cause, but in a large percentage of the cases, no mutation has been identified in the FH genes. METHODS: In accordance with the procedures of the European Atherosclerosis Society (EAS) FH registries network, the Mexican FH registry (www.fhmexico.org.mx) was launched in December 2017 to address the gaps in knowledge regarding this disease. Reference centres and the main nationwide public health providers have been invited to participate. RESULTS: To date, 142 cases have been registered. The mean age at diagnosis of probands is 36.42 ±â€¯19.9 years (adults and children). Tendon xanthomas or premature corneal arcus were present in 40% and 17.6%, respectively. Molecular analysis was present in 70%, with over 95% of alterations located on the LDL receptor gene. The median untreated LDL-C is 6.5 (5.6-8.4) mmol/l and the median on treatment LDL-C level is 4.3 ±â€¯1.7 mmol/l. CONCLUSIONS: The Mexican FH registry aims to obtain real world information regarding the management of patients in this country. By participating in this global call to action, we hope to improve both short and long term outcomes for all FH patients in Mexico.

Draft Genome Sequence of Escherichia coli Strain M15-4, a Typical Enteropathogenic E. coli Strain Isolated in Mexico.

We present here the first draft genome sequence of a typical enteropathogenic Escherichia coli serotype O55:H51 strain, M15-4, isolated from a 2-month-old infant girl with acute diarrhea. The study of this Mexican isolate will provide insights to the virulence and drug resistance traits involved in its pathogenic potential.

Draft Genome Sequence of a Mexican Community-Associated Methicillin-Resistant Staphylococcus epidermidis Strain.

We report here the first draft genome sequence of a Mexican communitarian methicillin-resistant Staphylococcus epidermidis (MRSE) strain whose genome harbors a wide variety of resistance determinants. The availability of this genome will allow the study of antibiotic resistance in Mexican staphylococci from a genomic perspective.

High prevalence of multidrug-resistant Escherichia coli isolates from children with and without diarrhoea and their susceptibility to the antibacterial activity of extracts/fractions of fruits native to Mexico.

PURPOSE: This paper aims to evaluate the antimicrobial resistance of Esherichia coli isolates from children under 5 years old, with and without diarrhoea, who were hospital outpatients in Culiacan, Sinaloa, Mexico. It also looks at the antimicrobial activity of fruit extracts against selected multidrug-resistant (MDR) E. coli strains. METHODOLOGY: A total of 205 E. coli isolates from stool samples were collected from 94 children under 5 years old who were outpatients from two hospitals in the city of Culiacan, Sinaloa, Mexico, during the autumn/winter of 2003/04; their resistance profiles to 19 commercial antimicrobials were investigated using the Kirby-Bauer method. The antibacterial activities of extracts/fractions of fruits (i.e. uvalama, Vitex mollis; ayale, Crescentia alata; and arrayan, Psidium sartorianum) were evaluated using the broth microdilution method. RESULTS: All E. coli isolates were susceptible to amikacin, nitrofurantoin and meropenem, and approximately 96 % were resistant to at least one antimicrobial, especially carbenicillin (93.2 %), cefuroxime sodium (53.7 %), ampicillin (40 %) and trimethoprim/sulfamethoxazole (35.1 %). Likewise, the frequency of MDR strains (44.9 %) was high, and no significant association with diarrhoea symptoms was found. Remarkably, all fruit extracts/fractions showed antibacterial activity against some, but not all, MDR isolates. The lowest minimal inhibitory concentration values were for the hexane fraction of arrayan (0.25 mg ml-1). CONCLUSION: A high number of antimicrobial-resistant E. coli (especially to ß-lactams and sulfonamides) and MDR isolates were detected in children under 5 years old, irrespective of diarrhoea symptoms; this is novel information for Culiacan, Sinaloa, Mexico. Moreover, our results showed that the studied fruit extracts/fractions are potential alternative or complementary treatments for MDR E. coli strains.

Fungal spore concentrations in indoor and outdoor air in university libraries, and their variations in response to changes in meteorological variables.

The fungal spore concentration (FSC) in the air poses a risk for human health. This work studied the FSC in university libraries and how it is affected by environmental factors. A total of 347 samples were obtained using a Microbio MB2(®) Aerosol Sampler. The wind speed (WS), cross wind (CW), temperature (T), relative humidity (HR), barometric pressure (BP) and dew point (DP) were recorded using a Kestrel(®) 4500 weather station. The median indoor/outdoor FSC was 360/1230 CFU m(-3). FSC correlated inversely with BP, HR and DP; and positively with WS and CW; whereas T showed negative or positive correlation with FSC, depending on the region or sampling time. Eleven fungal genera were found and the dominant isolates were identified as Aspergillus niger, Aspergillus tamarii and Aspergillus oryzae. All fungi identified are known to be allergenic. It was concluded that environmental variables can influence the air FSC in different ways.

Actividad antibacteriana de extractos de frutos de nanchi (Byrsonima crassifolia (L.) Kunth), arrayán (Psidium sartorianum (O. Berg) Nied.) y ayale (Crescentia alata Kunth) / Antibacterial activity of extracts obtained from the nanchi (Byrsonima crassifolia (L.) Kunth), arrayan (Psidium sartorianum (O. Berg) Nied.) and ayale (Crescentia alata Kunth) fruits

Nanchi (Byrsonima crassifolia), arrayan (Psidium sartorianum) and ayale (Crescentia alata) are wild and under-utilized plants from Mexico; their fruits have been used as food and as Mexican traditional remedies against human bacterial infections (e.g. bacillary dysentery). However, scientific reports which support such uses or promote their consumption are scarce. In this work, the antibacterial activities of fruit extracts (i.e. hexanic, HE; chloroformic, CE; and methanolic, ME) were determined by the micro-dilution assay, establishing the Minimum Inhibitory Concentration (MIC) and Minimum Bactericide Concentration (MBC) against 21 human pathogenic bacteria. The HE of arrayan and ayale showed the highest activity against enterobacteria (E. coli, Salmonella spp. and Shigella spp.) (MIC 0.25-2 mg/mL; MBC 0.5-16 mg/mL). The arrayan ME was the most active against the Gram-positive bacteria, showing Staphylococcus aureus the highest sensitivity (MIC 2 mg/mL; MBC 2-4 mg/mL). The presented results support the traditional uses of these plant materials for treating bacterial infectious diseases.

Nanchi (Byrsonima crassifolia), arrayán (Psidium sartorianum) y ayale (Crescentia alata) son plantas silvestres subutilizadas de México; sus frutos son comestibles y usados como medicamentos tradicionales contra infecciones bacterianas humanas (e.g. disentería bacilar). Sin embargo, los reportes científicos que avalen los usos y promuevan su consumo son escasos. En este trabajo se determinó, ensayo de micro-dilución en caldo, la Concentración Mínima Inhibitoria (CMI) y Concentración Mínima Bactericida (CMB), de los extractos de frutos (hexánico, EH; clorofórmico, EC; y metanólico, EM) contra 21 bacterias patógenas humanas. Los EH de arrayán y ayale mostraron la mayor actividad (CMI 0.25-2 mg/mL; CMB 0.5-16 mg/mL) contra enterobacterias (Escherichia coli, Salmonella spp. y Shigella spp.). El EM de arrayán fue el más activo contra bacterias Gram positivas, presentando Staphylococcus aureus la mayor sensibilidad (CMI 2 mg/mL; CMB 2-4 mg/mL). Estos resultados apoyan el uso tradicional de estos materiales en padecimientos asociados al tratamiento de infecciones bacterianas.

Physicochemical, nutritional and antibacterial characteristics of the fruit of Bromelia pinguin L.

Bromelia pinguin L. is a plant native to Sinaloa, Mexico, where its fruit is used as food or as a phytotherapeutic agent. The fruits of B. pinguin were characterized and they could be considered as a functional food. These fruits show an average weight of 13.7 g and a yellow color of high luminosity (b* = 43.2, L* = 74.5). The values for acidity (4.6%, as citric acid) and pH (3.7) of B. pinguin fruit are similar to those of citrics. The edible portion is characterized by a high content of vitamin C (126 mg/100 g), ash (10.6 g/100 g d.w.), crude fiber (3.4 g/100 g d.w.), calcium (1290 mg/100 g d.w.), magnesium (500 mg/100 g d.w.), manganese (2.95 mg/100 g d.w.) and it is a good source of zinc (2.8 mg/100 g d.w.). Polar fractions extracted from the pulp fruit showed activity against several genera of human pathogenic-bacteria (Staphylococcus, Streptococcus, Enterococcus, Salmonella, Shigella, Escherichia and Pseudomonas).

High-virulence clone of group B streptococci unable to grow at high temperatures is present in serotypes other than type III.

Highly virulent clonotypes of serotype III seem to cause much of the perinatal morbidity and mortality attributed to Streptococcus agalactiae (group B streptococci, GBS), One of these clonal types, designated the "high-virulence clone" (HVC), was identified by its inability to grow at 40 degrees C in a chemically defined medium. In the present study, this inability to grow at high temperatures was used as a marker to identify HVC in a sample of 286 Mexican GBS isolates. Forty-three isolates (15%) were identified as belonging to this clone: 15 were invasive isolates, 33 were serotype III (77%), and 10 were of serotypes other than type III (23%). These results demonstrate that HVC is more prevalent in Mexico than previously reported and that this clone is not restricted to serotype III isolates.

Serotypes of 286 group B streptococci isolated from asymptomatic carriers and invasive disease cases in Mexico.

BACKGROUND: Group B Streptococcus (GBS) remains as a leading cause of neonatal sepsis and meningitis in developed countries, where type III is the most common serotype. Although GBS is considered an uncommon cause of perinatal pathology in Mexico, a vaginal colonization rate of 14% in pregnant women and a neonatal infection rate of 1/1500 live births have been reported. The aim of this study was to determine the serotype distribution in a collection of 286 GBS strains isolated in Mexico from asymptomatic carriers and in adult and neonatal invasive disease cases. METHODS: The collection included GBS strains isolated between January 1988 and April 1998 at the Instituto Nacional de Perinatologia and Hospital de Pediatria in Mexico City. GBS and serotype were confirmed by latex agglutination. RESULTS: Most strains were isolated from asymptomatic carriers (66%). 30% were invasive isolates, and 10% of them were from neonates. 48.6% were type I, 32.9% type III, 14% type II, and 4% were non-typeable. CONCLUSION: Serotype I is predominant in Mexico but participation of serotype III is increasing, and a decrease of non-typeable isolates was detected.

Vaginosis bacteriana. Relación de la flora vaginal con las células epiteliales de vagina, con diferente tratamiento. Estudio ultraestructural / Bacterial vaginoss. relation of vaginal flora with epithelial cells of vagina, with different treatment. Ultraestrucural study

Los estudios relativos al tratamiento contra la vaginosis bacteriana han sido sobre efectividad probando concentraciones y tiempos del tratamiento. En el presente estudio analizamos la relación morfológica de la flora vaginal con el epitelio de la vagina, en mujeres con vaginosis bacteriana, en pre-tratamiento, primer postratamiento empleando metronidazol oral y fosfato de clindamicina intravaginal. De las 20 pacientes con vaginosis bacteriana, a 10 se les prescribió metronidazol oral 500 mg/2 al día X7 días; a las restantes, clindamicina 2 por ciento intravaginal una aplicación diaria por siete días. A las parejas se les suministró metronidazol en la dosis señalada. Las muestras obtenidas se procesaron mediante técnicas habituales para microscopia electrónica de transmisión. Se realizaron cortes ultrafinos de 100 mm de grosor y cortes seriados del mismo grosor. En pre-tratamiento las prolongaciones celulares ocasionaron mayor adhesión de las bacterias; asimismo, se encontraron restos de uniones celulares con bacterias adheridas. Se encontró penetración de algunas bacterias a las células epiteliales, corroborándose con cortes seriados y destacando la superposición de éstas en las células. Esta penetración se encontró en cinco casos y persistió en el primero y segundo postratamientos. En el primer postratamiento, se encontraron grupos celulares sin bacteria, la presencia de lactobacilos fue baja y aumentó posteriormente. La presencia de levaduras se presentó en el primer postratamiento y en algunos casos persistió. Es importante diferenciar la(s) bacteria(s) intracelulares e inferir las características relacionadas con la penetración bacteriana, para una adecuada prescripción y un mejor aprovechamiento de los fármacos previniendo posibles daños. La presencia de bacterias intracelularmente puede ser una de las causas de reincidencia de vaginosis bacteriana

Nuevas alternativas en el tratamiento de la vaginosis bacteriana / New treatment alternatives in bacterial vaginosis

Se comparó la eficacia y seguridad de clindamicina crema vaginal al 2 por ciento con metronidazol oral en el tratamiento de 184 mujeres con vaginosis bacteriana sintomática en un estudio multicéntrico, aleatorio, doble-ciego, controlado. La duración del tratamiento fue de siete días, utilizando placebo en cápsulas en el grupo clindamicina y placebo crema en el grupo metronidazol. Las pacientes fueron observadas durante las visitas de seguimiento (4-13 y 20-43 días después de completar su terapia). El resultado global del tratamiento, indicó que clindamicina en crama vaginal ofrece una eficacia similar a la demostrada con metronidazol oral. Los porcentajes de curación/mejoría fueron 87 por ciento para el grupo de clindamicina y 79 por ciento para el grupo de metronidazol, sin diferencias significativas (p> 0.22). No se observaron recaídas en el grupo de clindamicina mientras que el grupo de metronidazol, se presentaron en 7 por ciento de los casos. El porcentaje de fracaso fue menor en el grupo de clindamicina (3 por ciento) que en el grupo que recibió metronidazol oral (15 por ciento). Ambos fármacos fueron bien tolerados. Los efectos secundarios más frecuentemente observados fueron irritación vulvovaginal y el desarrollo de vaginitis/cervicitis. El único efecto secundario clasificado como serio fue erupción cutánea generalizada en una paciente que recibió metronidazol. Se concluye que la clindamicina en crema vaginal al 2 por ciento es una alternativa eficaz y segura al metronidazol oral, para el tratamiento de la vaginosis bacteriana; siendo el tratamiento de elección para las mujeres durante el primer trimestre de la gestación