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Background: Gram-negative bacilli are primarily responsible for the most common pediatric infections. Frequently, Escherichia fergusonii is identified as E. coli because of its close genetic proximity. Objectives: We aimed at the isolation and identification of multi-resistant strains of E. fergusonii, affecting children under two months of age. Methods: Strains were isolated from infectious processes and were identified phenotypically and molecularly. The microdilution method (MicroScan, autoSCAN-4) and the disk diffusion method (modified Kirby Bauer) were used to analyze antibiotic susceptibility. Results: Strains isolated were multi-resistant. Molecular identification provided the correct taxonomic assignment. Escherichia fergusonii strains were wrongly identified as E. coli with the phenotypic identification method. In addition, Pseudomonas aeruginosa and Klebsiella pneumoniae were identified. The best sensitivity results were obtained with Ceftazidime/avibactam and ceftolozane/tazobactam. Conclusions: We provided the first report of isolation and identification of multi-resistant E. fergusonii strains affecting children under two months of age in a neonatal intensive care unit.

An iron reducing enrichment was obtained from sulfate reducing sludge and was evaluated on the capability of reducing Fe3+ coupled to acetate oxidation in a microbial fuel cell (MFC). Three molar ratios for acetate/Fe3+ were evaluated (2/16, 3.4/27 and 6.9/55 mM). The percentages of Fe3+ reduction were in a range of 80–90, 60–70 and 40–50% for the MFCs at closed circuit for the molar ratios of 2/16, 3.4/27 and 6.9/55 mM, respectively. Acetate consumption was in a range of 80–90% in all cases. The results obtained at closed circuit for current density were: 11.37 mA/m2, 4.5 mA/m2 and 7.37 mA/m2 for the molar ratios of 2/16, 3.4/27 and 6.9/55 mM, respectively. Some microorganisms that were isolated and identified in the MFCs were Azospira oryzae, Cupriavidus metallidurans CH34, Enterobacter bugandensis 247BMC, Citrobacter freundii ATCC8090 and Citrobacter murliniae CDC2970-59, these bacteria have been reported as exoelectrogens in MFC and in MFC involving metals removal but not all of them have been reported to utilize acetate as preferred substrate. The results demonstrate that the isolates can utilize acetate as the sole source of carbon and suggest that Fe3+ reduction was carried out by a combination of different mechanisms (direct contact and redox mediators) utilized by the bacteria identified in the MFC. Storage of the energy generated from the 2/16 mM MFC system arranged in a series of three demonstrated that it is possible to utilize the energy to charge a battery.

Actinobacteria are prokaryotes with a large biotechnological interest due to their ability to produce secondary metabolites, produced by two main biosynthetic gene clusters (BGCs): polyketide synthase (PKS) and non-ribosomal peptide synthetase (NRPS). Most studies on bioactive products have been carried out on actinobacteria isolated from soil, freshwater or marine habitats, while very few have been focused on halophilic actinobacteria isolated from extreme environments. In this study we have carried out a comparative genomic analysis of the actinobacterial genus Saccharomonospora, which includes species isolated from soils, lake sediments, marine or hypersaline habitats. A total of 19 genome sequences of members of Saccharomonospora were retrieved and analyzed. We compared the 16S rRNA gene-based phylogeny of this genus with evolutionary relationships inferred using a phylogenomic approach obtaining almost identical topologies between both strategies. This method allowed us to unequivocally assign strains into species and to identify some taxonomic relationships that need to be revised. Our study supports a recent speciation event occurring between Saccharomonospora halophila and Saccharomonospora iraqiensis. Concerning the identification of BGCs, a total of 18 different types of BGCs were detected in the analyzed genomes of Saccharomonospora, including PKS, NRPS and hybrid clusters which might be able to synthetize 40 different putative products. In comparison to other genera of the Actinobacteria, members of the genus Saccharomonospora showed a high degree of novelty and diversity of BGCs.

Background: Some studies show changes in the microbiota in people undergoing antineoplastic treatment. Currently, there is not enough evidence of this effect in the treatment of cervical cancer (CC). The objective was to determine changes in the diversity of local cervical bacteria in women with CC receiving chemotherapy, radiotherapy, and brachytherapy. Materials and Methods: A descriptive, longitudinal, and prospective study was conducted in 68 women with locally advanced CC with a treatment plan based on the administration of chemotherapy, external beam radiotherapy, and brachytherapy. Cervical-vaginal fluid samples were taken during antineoplastic treatment. The samples were used to isolate bacterial strains. The bacteria were identified at the molecular level by comparing sequences of the 16S ribosomal RNA gene. Results: The bacteria identified belonged to three phyla: Firmicutes, Proteobacteria, and Actinobacteria. Nine genera and 25 species of bacteria were identified. The most frequent species were Staphylococcus epidermidis, Corynebacterium amycolatum, and Enterococcus faecalis. There were statistically significant differences when comparing bacterial diversity found in the different stages of treatment (≤0.05). Bacterial diversity decreased as antineoplastic treatment progressed and increased at the end of therapy. Conclusion: Antineoplastic treatments generate changes in the diversity of local cervical bacterial communities of women with CC.

Some microorganisms (such as bacteria) are capable of producing renewable energy without harassing the environment. Microbial fuel cells (MFC) offer thepossibility of transforming organic matter into electricity by using the metabolism of these microorganisms, creating ions within the subproducts of the metabolism that go to the extracellular environment. An electrode is set into the MFC that works as a final acceptor that attracts the electrons released by the microorganisms after consuming organic matter. To date, many microorganisms with the capability of liberating electrons through their metabolism have been identified. However only few are able of doing so without chemical mediators, which is why the search of new exoelectrogen microorganisms is of great importance. On the present work, two different MFC were employed for optimizing the isolation of exoelectrogenic bacteria gathered from mud of the Lerma river and from the Centro Interamericano de Recursos del Agua water treatment plant. Voltage generated by these microorganisms was compared with that created by Geobacter sulfurrenducens , one of the most efficient bacteria in this field. Overall, the obtained data show that the isolated bacteria at the National Institute of Nuclear Research facilities (identified by ribosomal RNA as Clostridium sordellii and C. bifermentans ) have a good voltage generation, although not as good as the one from G. sulfurrenducens . Results indicate that the strategy employed in the research is suitable for efficiently locating, isolating and identifying exoelectrogenic bacteria that may be used later on for the in situ generation of electricity in polluted areas.

Currently for bacterial identification and classification the rrs gene encoding 16S rRNA is used as a reference method for the analysis of strains of the genus Nocardia. However, it does not have enough polymorphism to differentiate them at the species level. This fact makes it necessary to search for molecular targets that can provide better identification. The sodA gene (encoding the enzyme superoxide dismutase) has had good results in identifying species of other Actinomycetes. In this study the sodA gene is proposed for the identification and differentiation at the species level of the genus Nocardia. We used 41 type species of various collections; a 386 bp fragment of the sodA gene was amplified and sequenced, and a phylogenetic analysis was performed comparing the genes rrs (1171 bp), hsp65 (401 bp), secA1 (494 bp), gyrB (1195 bp) and rpoB (401 bp). The sequences were aligned using the Clustal X program. Evolutionary trees according to the neighbour-joining method were created with the programs Phylo_win and MEGA 6. The specific variability of the sodA genus of the genus Nocardia was analysed. A high phylogenetic resolution, significant genetic variability, and specificity and reliability were observed for the differentiation of the isolates at the species level. The polymorphism observed in the sodA gene sequence contains variable regions that allow the discrimination of closely related Nocardia species. The clear specificity, despite its small size, proves to be of great advantage for use in taxonomic studies and clinical diagnosis of the genus Nocardia.

Purpose. Under certain circumstances, Actinomyces behaves as an opportunistic microorganism and can cause actinomycosis, a chronic and inflammatory granulomatous infection. The purpose of this project was to detect the presence of Actinomyces in cervical exudates from women with cervical intraepithelial neoplasia (CIN) and women with cervical cancer. Methodology. Cervical samples from 92 women were divided into three groups: CIN, cervical cancer and healthy women. Metagenomic DNA extraction was performed following the Qiagen QIAamp Mini Kit protocol. A specific fragment (675 bp) was amplified by PCR in order to detect the presence of Actinomycetales. Samples in which Actinomycetales was detected were subjected to separate amplification reactions with primer pairs for A. israelii, A. viscosus, A. meyeri and A. odontolyticus. Amplified products were observed by 2 % agarose gel electrophoresis. Results. Actinomyces were found in 10 % of women with CIN, 36.6 % of women with cervical cancer and 9 % of healthy women. The species identified in this study were A. meyeri in 14/92 samples (15.2 %), A. viscosus in 10/92 samples (10.8 %), A. odontolyticus in 4/92 samples (4.3 %) and A. israelii in 6/92 samples (6.5 %). Conclusion. Patients with cervical cancer had a higher prevalence of the presence of Actinomyces compared to the CIN and control groups. This is the first study in which a deliberate search of this genus has been performed in women with cervical pathologies. The use of specific primers for each species facilitated their detection in comparison with traditional isolation methods. More information is necessary to understand the molecular mechanisms involved in the complex role that bacterial communities may play in the development of cancer (and vice versa).

Mycobacteriumgenus causes a variety of zoonotic diseases. The best known example is the zoonotic tuberculosis due toM. bovis. Much less is known about “nontuberculous mycobacteria (NTM),” which are also associated with infections in humans. The Mexican standard NOM-ZOO-031-1995 regulates the presence ofM. bovisin cattle; however, no regulation exists for the NTM species. The objective of this study was to isolate and identify nontuberculous mycobacteria species from cattle of local herds in the south region of the State of Mexico through the identification and detection of the 100 bp molecular marker in the 23S rRNA gene with subsequent sequencing of the 16S rRNA gene. Milk samples (35) and nasal exudate samples (68) were collected. From the 108 strains isolated, 39 were selected for identification. Thirteen strains isolated from nasal exudates amplified the 100 bp molecular marker and were identified asM. neoaurum(six strains),M. parafortuitum(four strains),M. moriokaense(two strains), andM. confluentis(one strain). ExceptM. parafortuitum, the other species identified are of public health and veterinary concern because they are pathogenic to humans, especially those with underlying medical conditions.

Metals such as Al, Fe and Hg are used in diverse anthropogenic activities. Their presence in water bodies is due mainly to domestic, agricultural and industrial wastewater discharges and constitutes a hazard for the organisms inhabiting these environments. The present study aimed to evaluate geno- and cytotoxicity induced by Al, Fe, Hg and the mixture of these metals on blood of the common carp Cyprinus carpio. Specimens were exposed to the permissible limits in water for human use and consumption according to the pertinent official Mexican norm [official Mexican norm NOM-127-SSA1-1994] Al (0.2mgL-1), Fe (0.3mgL-1), Hg (0.001mgL-1) and their mixture for 12, 24, 48, 72 and 96h. Biomarkers of genotoxicity (comet assay and micronucleus test) and cytotoxicity (caspase-3 activity and TUNEL assay) were evaluated. Significant increases relative to the control group (p

Background: The opportunistic pathogen Klebsiella pneumoniae is one of the main causes of pediatric bacterial blood stream infections (BSI), which is complicated with sepsis and high mortality. Objectives: To identify atypical Klebsiella species affecting a sample of infected neonates with low antimicrobial response. Methods: Multidrug resistant blood cultures for Klebsiella from a Neonatal Service, were submitted to molecular identification by sequencing analysis of 16S ribosomal RNA. Results: The mean age of the newborns was 14.7 ± 5.6 days. A total of 6 out of 8 cases were sepsis, 1 case of pneumonia, and 1 a catheter-related infection. The molecular identification showed 3 cases of K. pneumoniae subsp. ozaenae, 2 of K. pneumoniae and K. variicola, and 1 case of K. oxytoca. The highest antimicrobial resistance was against cephalosporins and Trimethoprim/sulfamethoxazole. Conclusions: Klebsiella pneumoniae subsp. ozaenae was responsible for multidrug resistant strains of Klebsiella even in 37.5% of cases. In our clinical setting, the use of Amikacin and carbapenems are still useful to treat neonatal infections by Klebsiella even against K. variicola, which is the most resistant.

Characterization and understanding of gut microbiota has recently increased representing a wide research field, especially in autoimmune diseases. Gut microbiota is the major source of microbes which might exert beneficial as well as pathogenic effects on human health. Intestinal microbiome’s role as mediator of inflammation has only recently emerged. Microbiota has been observed to differ in subjects with early rheumatoid arthritis compared to controls, and this finding has commanded this study as a possible autoimmune process. Studies with intestinal microbiota have shown that rheumatoid arthritis is characterized by an expansion and/or decrease of bacterial groups as compared to controls. In this review, we present evidence linking intestinal dysbiosis with the autoimmune mechanisms involved in the development of rheumatoid arthritis.

Polycyclic aromatic hydrocarbons (PAHs) are compounds that can be quantified by fluorescence due to their high quantum yield. Haloalkalitolerant bacteria tolerate wide concentration ranges of NaCl and pH. They are potentially useful in the PAHs bioremediation of saline environments. However, it is known that salinity of the sample affects fluorescence signal regardless of the method. The objective of this work was to carry out a comparative study based on the sensitivity, linearity, and detection limits of the excitation, emission, and synchronous fluorescence methods, during the quantification of the residual anthracene concentration from the following haloalkalitolerant actinomycetes culturesKocuria rosea, Kocuria palustris, Microbacterium testaceum, and 4 strains ofNocardia farcinica, in order to establish the proper fluorescence method to study the PAHs biodegrading capacity of haloalkalitolerant actinobacteria. The study demonstrated statistical differences among the strains and among the fluorescence methods regarding the anthracene residual concentration. The results showed that excitation and emission fluorescence methods performed very similarly but sensitivity in excitation fluorescence is slightly higher. Synchronous fluorescence usingΔλ=150 nm is not the most convenient method. Therefore we propose the excitation fluorescence as the fluorescence method to be used in the study of the PAHs biodegrading capacity of haloalkalitolerant actinomycetes.

Summary Objective The aim of our research was to update the situation concerning actinomycetoma in Mexico, to localize areas where it is frequently found and to identify the main strains from the isolates. Material and methods To localize cases of actinomycetoma, patients’ medical records from the dermatology departments of general and private hospitals were reviewed. Pathologic strains were looked for in general hospital patients and in reference institutes in Mexico City. The clinical strains were kept in Bennett agar and were subsequently identified using polyphasic approaches, including a partial sequence of 16S rDNA using species-specific primers designed to recognise Nocardia species. Results Eleven cases of actinomycetoma and five species of pathological strains were identified. Most cases were found in south-eastern Mexico and Nocardia brasiliensis was the most frequently isolated species. Conclusions This research confirmed the presence of actinomycetoma in Mexico as well as the zones of high incidence and the most frequent pathological strain.

Nocardia species are aerobic, Gram-positive bacteria with branched filaments reported as opportunistic microorganisms associated with infectious diseases of the skin. We report the isolation of N. wallacei in Mexico from a 43-year-old man, an HIV-positive construction worker who sought care for difficulty breathing and abundant sputum.

Actinomycetes are a group of Gram-positive filamentous bacteria. They are widely distributed microorganisms, that are prevalent in tropical and subtropical areas. In addition to the pathogenic species, some actinomycetes species are of great biotechnological importance. Nowadays, the isolation and amplification of nucleic acids is an important technique in most molecular biology research laboratories and the quality and purity of the DNA used for amplification reactions is critical. This paper describes a rapid method to verify the purity of DNA by preliminary amplification of an insert in the rRNA 23S gene.

The objective of this study was to determine seroprevalence and identify risk factors associated withToxocara canisinfection. A clinical and epidemiological questionnaire and body mass index were used to assess the risk factors associated with human toxocariasis in 108 children with an age range of 2–16 years. Antibodies againstToxocara caniswere detected using an ELISA test kit. Chi-square analysis and odds ratio (OR) were used to identify risk factors associated withToxocara canisseropositivity. The prevalence of antibodies againstToxocara caniswas greater (P=0.02) in males than females (28.84% and 16.07%, resp.). Chi-square analysis and odds ratio revealed just one variable withP<0.05,andOR>1.0was associated with seropositivity: the possession of dogs under one year old (OR=1.78). Although not significant, the OR values suggest that other factors may be epidemiologically important forToxocarapresence such as not washing hands before meals, malnutrition, obesity, and use of public parks. Children in the age group >12 and Toxocara canis(17.59%) than the >2 and

The aim of this paper was to determine in 32 patients from 4 different Mexican hospitals the frequency of opportunistic bacteria in the 2010 to 2011 time period. The patients were divided in 4 groups. Group 1 included 21 HIV positive patients with acute respiratory syndrome. Four HIV positive patients with tuberculosis symptoms were included in Group 2; two patients with tuberculosis symptoms and one asymptomatic person formed Group 3. Reference Group 4 included 4 patients from whom 4 strains ofMycobacteriumspp. had been reported. The strains were isolated and identified by 16S rRNA gene amplification, API 20E and 50CH, biochemical test, and antibiotic sensitivity. The strains found were 10Pantoea agglomerans, 6Mycobacteriumspp., 6Pseudomonasspp. and 10 strains of normal floral species:Thermoactinomycetes bacterium(1),Enterococcus faecium(2),Bacillus licheniformis(1),Lactobacillus rhamnosus(2),Streptococcus oralis(2),Streptococcus anginosus(1), andEnterobacter hormaechei(1).

Summary Background Mexico has the largest number of clinical cases of actinomycetoma in North and South America. Species originally identified by less specific methods have been recently reclassified as other known species or as new species. Objective To assess, by 16S rRNA gene sequencing and phenotypic methods, the species distribution of 18 human clinical isolates originally identified as N. brasiliensis , some of them isolated between 1947 and 1959 in Mexico City. Methods Clinical isolates came from the Hospital General, “Dr. Manuel Gea Gonzalez”, and Instituto Nacional de Diagnostico y Referencia Epidemiologica (INDRE) in Mexico, D.F. The strains used in this study included 15 clinical strains isolated between 1947 and 1959 that were originally identified as N. brasiliensis and three more strains obtained in 2007 identified as Nocardia spp. The isolates were identified genotypically by sequencing the 16S rRNA gene, and their phenotypic profiles were obtained with the API Coryne ® system. Antibiotic susceptibility patterns were tested according to the protocol of the Comite de l’antibiogramme de la Societe francaise de microbiologie [4] . Results According to 16S rRNA gene, sequencing were identified among 18 human clinical isolates as Nocardia farcinica ( n = 11) and Nocardia brasiliensis ( n = 7). A high number of the strains were susceptible to the majority of the antibiotics tested. The phenotypic profiles of the strains were quite uniform for N. farcinica and some variability was observed for N. brasiliensis strains. Conclusion N. farcinica was the most prevalent species identified. Modern methodologies should be applied in clinical laboratories to accurately identify etiological agents.

Sandra Díaz González-Vieyra1, Ninfa Ramírez-Durán2, Ángel H Sandoval-Trujillo3, Juan C Vázquez-Chagoyán1, Humberto G Monroy-Salazar1, Alberto Barbabosa-Pliego11Research Center of Advanced Studies in Animal Health, Veterinary Husbandry School, 2Medical and Ambiental Microbiology, Research Center of Advanced Studies in Health Science, School of Medicine, Autonomous University of the State of Mexico, Toluca, Mexico; 3Department of Biological Systems, Metropolitan Autonomous University, Xochimilco, Mexico City, MexicoAbstract: Chagas disease caused by Trypanosoma cruzi is an important public health problem in Latin America. Dogs are considered a risk factor for human Chagas disease, a sentinel for T. cruzi infection in endemic regions and an animal model to study pathological aspects of the disease. The potential use of dogs as indicators of human cardiac pathogenicity of local T. cruzi strains has been studied insufficiently. We studied electrocardiographic (EKG) and echocardiographic (ECG) alteration frequencies observed in an open population of dogs in Malinalco, Mexico, and determined if such frequencies were statistically associated with T. cruzi infection in dogs. Animals (n = 139) were clinically examined and owners were asked to answer a questionnaire about dogs’ living conditions. Two commercial serological tests (IHA, ELISA) were conducted to detect anti-T. cruzi serum antibodies. Significant differences between seropositive and seronegative animals in cardiomyopathic frequencies were detected through EKG and ECG (P < 0.05). Thirty dogs (21.58%) were serologically positive to anti-T. cruzi antibodies (to ELISA and IHA assays), of which nine (30%) had EKG and/or ECG alterations. From the remaining 104 (78.42%) seronegative animals, five (4.5%) had EKG and/or ECG abnormalities. Our data support the hypothesis that most EKG and ECG alterations found in dogs from Malinalco could be associated with T. cruzi infection. Considering the dog as a sentinel and as an animal model for Chagas disease in humans, our findings suggest that the T. cruzi strains circulating in Malinalco have the potential to produce cardiomyopathies in infected humans.Keywords: chagas disease, Trypanosoma cruzi, cardiomyopathy, electrocardiography, echocardiography, Malinalco, México