Factors Affecting Spontaneous Endocytosis and Survival of Probiotic Lactobacilli in Human Intestinal Epithelial Cells.

Mutualistic bacteria have different forms of interaction with the host. In contrast to the invasion of pathogenic bacteria, naturally occurring internalization of commensal bacteria has not been studied in depth. Three in vitro methods, gentamicin protection, flow cytometry and confocal laser scanning microscopy, have been implemented to accurately assess the internalization of two lactobacillus strains-Lacticaseibacillus paracasei BL23 and Lacticaseibacillus rhamnosus GG-in Caco-2 and T84 intestinal epithelial cells (IECs) under a variety of physiological conditions and with specific inhibitors. First and most interesting, internalization occurred at a variable rate that depends on the bacterial strain and IEC line, and the most efficient was BL23 internalization by T84 and, second, efficient internalization required active IEC proliferation, as it improved naturally at the early confluence stages and by stimulation with epidermal growth factor (EGF). IFN-γ is bound to innate immune responses and autolysis; this cytokine had a significant effect on internalization, as shown by flow cytometry, but increased internalization was not perceived in all conditions, possibly because it was also stimulating autolysis and, as a consequence, the viability of bacteria after uptake could be affected. Bacterial uptake required actin polymerization, as shown by cytochalasin D inhibition, and it was partially bound to clathrin and caveolin dependent endocytosis. It also showed partial inhibition by ML7 indicating the involvement of cholesterol lipid rafts and myosin light chain kinase (MLCK) activation, at least in the LGG uptake by Caco-2. Most interestingly, bacteria remained viable inside the IEC for as long as 72 h without damaging the epithelial cells, and paracellular transcytosis was observed. These results stressed the fact that internalization of commensal and mutualistic bacteria is a natural, nonpathogenic process that may be relevant in crosstalk processes between the intestinal populations and the host, and future studies could determine its connection to processes such as commensal tolerance, resilience of microbial populations or transorganic bacterial migration.

Drug resistance and phylogenetic grouping of bacteria isolated from visitors' hands in a secondary-care hospital.

INTRODUCTION: Dynamic movement in the hospital environment promotes the transmission of nosocomial pathogens and multidrug resistance mechanisms through the dissemination of organisms that carry genetic determinants. Healthcare workers play an important role in the spread of pathogens; however, the role of visitors in this environment is poorly understood. OBJECTIVE: This study aimed to molecularly identify and examine the antibiotic resistance of the palmar microbiota of patients' companions in a hospital waiting room. METHODOLOGY: Twenty-five palmar surface and interdigital space sample swabs were randomly collected and cultured on blood agar plates, and 19 colonies with different macro- and microscopic characteristics were isolated. The V4 and V6 hypervariable regions of the 16S rRNA gene from each isolate were amplified by PCR and sequenced. Maximum likelihood- and Bayesian inference-based phylogenetic analyses were performed to determine taxonomic relationships. Antibiotic resistance was evaluated by disk diffusion and broth microdilution. RESULTS: Among the isolates, 52.6% were related to Bacillus, 36.8% to Staphylococcus, 5.3% to Enterococcus and 5.3% to Atlantibacter. All of the isolates exhibited ampicillin and penicillin resistance, while 94.7% also exhibited dicloxacillin resistance. Staphylococcus aureus was resistant to penicillins but sensitive to the remaining drugs. Bacteria identified as Bacillus subtilis (MLM14B99), Bacillus pumilus (MLM23B07 and MLM25B06), Staphylococcus epidermidis (MLM24S31 and MLM29S04), and Enterococcus (MLM22E08) showed resistance to at least 46.7% of the antibiotics. CONCLUSIONS: To decrease the transmission of pathogenic bacteria with an antibiotic resistance profile, re-evaluation of hand cleaning measures and their application by people who visit hospital centres is needed.

A Change in Conservation Status of Pachyphytum caesium (Crassulaceae), a Threatened Species from Central Mexico Based on Genetic Studies.

Genetic studies in rare species are important to determine their patterns of genetic diversity among populations and implement conservation plans aimed to reduce extinction risks. Pachyphytum caesium is an endemic species with extremely small populations in central Mexico. This work analyzes the diversity and genetic structure of Pachyphytum cesium (Crassulaceae) to change the conservation status and propose conservation strategies. Twelve dominant ISSR markers were used to describe the genetic diversity of all known populations. Additionally, we carried out two simulations to explore how the loss of individuals or the local populations extinction affect the genetics parameters of the species. The average results indicated moderate levels of genetic diversity (number of alleles = 89.7 ± 3.9, expected heterozygosity = 0.212 ± 0.0, and percentage of polymorphic loci = 56.1 ± 3.9), parameters that decreased significantly when simulations were performed in P. caesium. Additionally, a genetic structure of the populations was found with low gene flow (Nm = 0.92). Genetic parameters are negatively affected by the loss of individuals and the local extinction of populations. Based on our results, we propose to reclassify the conservation status of the species in danger of extinction, hence a series of conservation strategies are provided to prevent its disappearance.

Determination of drug-resistant bacteria in palmar surface and touchscreen cell phones from bystanders in an urban community.

The dynamic microbiota of the human palmar surface (PS) is related to the various hygienic habits of humans and can be transmitted or exchanged upon contact with objects of daily use, such as the indispensable touchscreen cell phone (TCP); this interaction could allow the development of drug-resistant bacteria. The objective was to determine the drug-resistant bacterial contamination between PSs and TCPs in an urban community. Among the total bacterial colonies isolated and molecular and phylogenetically characterized based on the V4-V6 regions of the 16S rRNA gene from PSs and TCPs, the genera present in both types of samples were Staphylococcus (53.3 and 43.5 %, respectively), Bacillus (37.8, 37 %), Atlantibacter (2.2, 10.8 %) and Microbacterium (2.2, 4.3 %). The genera present in only one type of sample were Rothia, Paenibacillus, Escherichia and Micrococcus (2.2 % each). Resistance to penicillins (35.6-93.5 %) and nonsusceptibility to cephalosporins (8.9-37 %) and nitrofurantoin (13.3 and 15.2 %) were observed. The percentage of multidrug antibiotic resistance was 15.4 %. The prevalence of drug-resistant and multidrug-resistant bacteria in PSs and TCPs in the community could give rise to human health problems, and hygiene measures are recommended.

Evaluation of nest management phases for Lepidochelys olivacea at two beaches in Northwest Mexico.

The olive ridley turtle, Lepidochelys olivacea, is a vulnerable and endangered species according to the IUCN and Mexican Official Standard NOM-059, respectively. On most solitary nesting beaches of olive ridley turtles, the eggs are removed from the in situ nest to hatcheries due to the high incidence of predation, human poaching, and beach erosion; therefore, it is necessary to collect and analyze information on the protection activities conducted for this species from egg laying to hatchling release. In general, protection activities during nest management can be divided into 5 phases: nest logging (F1), egg collection (F2), egg transfer (F3), egg incubation and hatching (F4), and hatchling release (F5). This work was carried out on two Pacific beaches in northwestern Mexico, Ceuta Beach Sanctuary (CBS) during 2013-2019 and Caimanero Beach (CB) during the 2013-2018 nesting seasons, with the objective of quantitatively evaluating the management phases of the protection program for olive ridley turtles by assessing the nest, egg, and hatchling losses in each of the phases using the model of Godínez-Domínguez et al. (1991). The results of the statistical analyses indicate that the greatest losses occurred during the incubation phase (F4) at both beaches, with a 41.99% loss at CBS and a 33.09% loss at CB, followed by the F2 (with 15.56 and 27.27% losses, respectively) and F1 (21.28 and 25.56% losses, respectively) phases. Significant differences between the beaches were observed in F4, F5 and F3, with greater losses at CBS than at CB, indicating that the success of the management phases may vary among beaches. The results obtained show that it is necessary to focus on strategies for improving the success of mainly phase F4 and phases F1 and F2 at both beaches.

Nesting trends of olive ridley sea turtles Lepidochelys olivacea (Testudinata: Cheloniidae) on two beaches in Northwestern Mexico after 30 and 40 years of conservation / Tendencias de anidación de la tortuga golfina Lepidochelys olivacea (Testudinata: Cheloniidae) en dos playas del noroeste de México después de 30 y 40 años de conservación

Abstract Introduction: Although olive ridley sea turtle (Lepidochelys olivacea) are the most abundant sea turtles in the world, quantitative information is scarce and unevenly distributed among regions. There are many management and conservation programs for this species, and assessments are necessary to identify nesting trends and effectively manage current conservation programs. PROTORMAR-UAS is a Research and Conservation program for the olive ridley turtle created by the Autonomous University of Sinaloa, Mexico. The program utilizes two biological stations: Santuario Playa Ceuta (SPC) and Playa Caimanero (PC). Objective: To evaluate the nesting trend of olive ridley turtles on two beaches in Northwestern Mexico and to predict prospective nesting trends for the next 30 years. Methods: Using annual nesting data collected over 40 years at SPC (1976-2016) and 30 years at PC (1986-2016), we evaluated nesting trends, hatching success, predation and poaching of olive ridley turtles on the two beaches in Northwestern Mexico. Then, prospective nesting estimates for the next 30 years were calculated predictive time series model. Results: A positive and significant correlation was identified between the number of annual nests and time for both beaches (rho = 0.850, P ≤ 0.01 for SPC; rho = 0.677, P ≤ 0.01 for PC); the average hatching success rates were 65.09 at SPC and 60.72 % at PC. The predictive time-series model indicated that the numbers of nests will continue to increase through 2045, increasing three-fold at SPC and six-fold at PC with respect to the last year of monitoring. Conclusions: There was a clear positive trend in the number of olive ridley sea turtle nests at both sites, which is consistent with trends found in other recent studies from the region. Therefore, we suggest that PC be designated a legally protected nesting area since it is located within the latitudinal limits of olive ridley nesting and given the need for resources for camp operation considering increased nesting and current problems with predation and poaching. Because in Mexico operating a nesting beach without any protection status implies not having a budget for its management.

Resumen Introducción: A pesar de que las tortugas golfinas (Lepidochelys olivacea) son las tortugas marinas más abundantes del mundo, su información cuantitativa disponible es escasa y se encuentra distribuida de manera desigual entre regiones. Existen muchos programas de manejo y conservación para esta especie, y sus evaluaciones son necesarias para identificar tendencias de anidación y poder manejar de manera efectiva los programas de conservación actuales. PROTORMAR-UAS es un programa de Investigación y Conservación de la tortuga golfina creado por la Universidad Autónoma de Sinaloa, México. El Programa cuenta con dos estaciones biológicas: Santuario de Playa Ceuta (SPC) y Playa Caimanero (PC). Objetivo: Evaluar la tendencia de anidación de la tortuga golfina en dos playas del noroeste de México y predecir las tendencias prospectivas de anidación para los próximos 30 años. Métodos: A partir de los datos de registros anuales de anidación de 40 años para SPC (1976-2016) y 30 años para PC (1986-2016), evaluamos las tendencias de anidación, el éxito de la eclosión y los problemas de depredación y saqueo de nidos de la tortuga golfina en las dos playas del noroeste de México. Posteriormente, se calcularon las estimaciones prospectivas de anidación para los próximos 30 años usando un modelo predictivo de series de tiempo. Resultados: Se identificó una correlación positiva y significativa entre el registro anual de nidos y el tiempo de estudio para ambas playas (rho = 0.850, P ≤ 0.01 para SPC; rho = 0.677 y P ≤ 0.01 para PC); así como el éxito de eclosión promedio de 65.09 para SPC y de 60.72 % para PC. El modelo predictivo de series de tiempo indicó que las anidaciones continuarán aumentando para el 2045, tres veces para SPC y seis para PC, con respecto al último año de monitoreo. Conclusiones: Hay una clara tendencia positiva de anidación de la tortuga golfina en ambos sitios, lo cual es consistente con la tendencia observada en otros estudios recientes de la región. Por lo tanto, sugerimos incluir a PC como un área de anidación legalmente protegida, la cual se ubica en los límites latitudinales de anidación de la tortuga golfina, dada la necesidad de contar con recursos disponibles para la operación del campamento ante el aumento de anidaciones y de problemas de depredación y saqueo. Porque en México operar una playa de anidación sin ningún estatus de protección implica no tener presupuesto para su manejo.

Phylogenetic characterization and multidrug resistance of bacteria isolated from seafood cocktails.

The continual increase in resistance to antibacterial drugs has become a major public health problem, and their indiscriminate use in agriculture, aquaculture, and the treatment of human and animal diseases has severely contributed to the occurrence and spread of multidrug resistance genes. This study phylogenetically characterized multidrug-resistant bacteria isolated from seafood cocktails. Seafood cocktail dishes from 20 establishments on public roads were sampled. Samples were grown on TCBS agar and blood agar. Forty colonies with different macro- and microscopic characteristics were isolated. The 16S rRNA gene V4 and V6 hypervariable regions were amplified, sequenced and phylogenetically analyzed. Antibacterial drug resistance was determined by disk diffusion assay. Isolated bacteria were identical to species of the genera Enterococcus, Proteus, Vibrio, Staphylococcus, Lactococcus, Vagococcus, Micrococcus, Acinetobacter, Enterobacter, and Brevibacterium, with 75-100% presenting resistance or intermediate resistance to dicloxacillin, ampicillin, and penicillin; 50-70% to cephalosporins; 30-67.5% to amikacin, netilmicin and gentamicin; 40% to nitrofurantoin and other antibacterial drugs; 25% to chloramphenicol; and 2.5% to trimethoprim with sulfamethoxazole. In general, 80% of the bacteria showed resistance to multiple antibiotics. The high degree of bacterial resistance to antibacterial drugs indicates that their use in producing raw material for marine foods requires established guidelines and the implementation of good practices.

Isolation of Gram-Positive, Antibiotic-Resistant Bacteria from Tactile Mobile Phones in a Northwestern Mexican City.

The widespread use of touch-screen mobile devices renders them potential fomites for the transmission of bacterial pathogens among users of different ages. The objectives of the present research were to isolate bacteria from mobile phones, perform molecular and phylogenetic identification, and determine the antibiotic resistance profiles. The surfaces of 50 touch-screen mobile devices owned by bystanders were sampled in the city center of Culiacan, Sinaloa, Mexico. The samples were cultured on nutritive agar; 13 bacterial colonies were isolated and characterized based on their macroscopic and microscopic characteristics and then identified using PCR amplification and sequencing of the 16S rRNA gene V4 and V6 regions. Their taxonomic relationships were determined via a Bayesian inference approach. Antimicrobial resistance was evaluated via disc diffusion and broth microdilution assays. Species of the genera Staphylococcus, Bacillus, and Enterococcus were identified on 84.6, 7.7, and 7.7% of the mobile phones, respectively. A unique subgroup of Staphylococcus epidermidis was identified in strains FBOPL-23, CAEPL-28, and FREPL-28. Staphylococcus hominis novobiosepticus was also identified on mobile phones for the first time. Of the isolated bacteria, 92.3% were resistant to erythromycin, 76.9% to ampicillin and penicillin, 61.5% to dicloxacillin, 38.5% to cephalothin and 7.7% to cefotaxime and ceftriaxone. The presence of antibiotic-resistant bacteria of clinical relevance poses potential risks to users' health and the dissemination of antibiotic resistance mechanisms throughout the community; thus, we recommend regular cleaning to prevent cross-infection by multidrug-resistant bacteria when using touch-screen mobile devices.

Identification of immunodominant peptides from Gnathostoma binucleatum.

Gnathostomiasis is now recognized as a zoonosis with a worldwide distribution. In the Americas, it is caused by the third-stage larvae of Gnathostoma binucleatum and in Asia mainly by G. spinigerum. The availability and preparation of specific antigens are among the main obstacles for developing reliable immunodiagnostic tests. In this study, six immunodominant peptides were identified and characterized from G. binucleatum, somatic antigens (AgS: 24, 32, and 40 kDa) and excretory-secretory antigens (AgES: 42, 44, and 56 kDa) by two-dimensional immunoblot analysis. Among those immunodominant peptides, two AgS spots were characterized by mass spectrometric analysis (32 kDa; pI 6.3 and 6.5) and identified as type 1 galectins. In accordance with this finding, a fraction of AgS exhibited affinity to lactose and displayed a 100% specificity and sensitivity for the diagnosis of human gnathostomiasis.

Is Gnathostoma turgidum an annual parasite of opossums? Drastic seasonal changes of infection in Didelphis virginiana in Mexico.

Gnathostoma turgidum is a nematode that parasitizes the stomach of opossums, Didelphis virginiana. Despite its wide distribution in the Americas, its natural life cycle is poorly understood. Recently, we found an endemic area for G. turgidum infection in Sinaloa, Mexico (Diaz-Camacho et al., 2009). Based on sporadic surveys for several years, the prevalence was apparently high in summer and extremely low in winter. To confirm that this is really a seasonal variance, we conducted a longitudinal survey on G. turgidum infection in opossums from November 2007 to November 2008. The results showed amazing seasonal changes in the prevalence, with synchronized migration and maturation of worms in opossums. Between February and March, many juvenile worms, with occasional AL3, were found in the liver, but no worms were found in the stomach. Mature adult worms began to appear in the stomach around April and rapidly increased in number toward July, when all worms resided in the stomach. Then, the worms disappeared almost completely by November. These results suggest that G. turgidum is an annual parasite of the opossum, D. virginiana, in Mexico.

Identification of estuarine fish Dormitator latifrons as an intermediate host and Eleotris picta as a paratenic host for Gnathostoma binucleatum in Sinaloa, Mexico.

Gnathostomosis is a typical fish-borne zoonotic parasitosis and is currently a serious public health issue in Mexico. Among several Gnathostoma species present in wild animals in Mexico, Gnathostoma binucleatum is the only proven species responsible for human diseases, and the advanced third stage larvae (AL3) of G. binucleatum have been found in over 20 species of fish in this country. In Sinaloa State, two fish species, Dormitator latifrons and Eleotris picta, were heavily contaminated with G. binucleatum AL3. When we analyzed the relationship between the size of the fish and the density of infection with G. binucleatum AL3, the distribution patterns of AL3 were markedly different between these two fish species. Apparent size-dependent accumulation was observed in E. picta but not in D. latifrons, suggesting that E. picta is a paratenic host whereas D. latifrons is a second intermediate host.

Physicochemical and nutritional characteristics of the fruit of Zizyphus sonorensis S. Wats (Rhamnaceae).

The nanche de la costa (Zizyphus sonorensis) fruit was partially characterized by physicochemical and nutritional analyses. This fruit has a homogenous size and color and low moisture content (47 g/100 g). The content of tannins and nickel of the edible portion might limit its use. However, nanche de la costa has important characteristics and potential to be considered as a food or feed source. The remarkable characteristics of the edible portion are high content of total (35 g/100 g) and soluble (0.6 g/100 g) dietary fiber, high level of copper (0.53 mg/100 g), iron (10 mg/100 g) and zinc (4.2 mg/100 g). The seed was distinguished by its high content of total dietary fiber (82.1 g/100 g), calcium (540 mg/100 g), copper (0.54 mg/100 g), chromium (1.1 mg/100 g) and zinc (4.5 mg/100 g). The moisture value is given in fresh weight basis and all other values are in dry weight basis.