Serodiversity, antibiotic resistance, and virulence genes of Vibrio parahaemolyticus in oysters collected in coastal areas of northwestern Mexico between 2012 and 2020.

This study aimed to determine the prevalence of V. parahaemolyticus in oysters from the northwestern coast of Mexico and to identify the serotypes, virulence factors, and antibiotic resistance of the strains. Oyster samples were collected from 2012 to 2020 from the northwest coast of Mexico; biochemical and molecular methods were used to identify V. parahaemolyticus from oysters; antiserum reaction to determine V. parahaemolyticus serotypes, and PCR assays were performed to identify pathogenic (tdh and/or trh) or pandemic (toxRS/new, and/or orf8) strains and antibiotic resistance testing. A total of 441 oyster samples were collected and tested for V. parahaemolyticus. Forty-seven percent of oyster samples were positive for V. parahaemolyticus. Ten different O serogroups and 72 serovars were identified, predominantly serotype O1:KUT with 22.2% and OUT:KUT with 17.3%. Twenty new serotypes that had not been previously reported in our region were identified. We detected 4.3% of pathogenic clones but no pandemic strains. About 73.5% of strains were resistant to at least one antibiotic, mainly ampicillin and ciprofloxacin; 25% were multi-drug resistant. In conclusion, the pathogenic strains in oysters and antibiotic resistance are of public health concern, as the potential for outbreaks throughout northwestern Mexico is well established.

Comparison of the blood biochemical values of foraging and nesting Olive Ridley turtles (Lepidochelys olivacea) from Sinaloa, Mexico.

Our study aimed to establish reference values for nesting females and compare them with those previously reported to understand olive ridley turtles' health status and contribute to long-term health assessment and monitoring in foraging and nesting areas from the state of Sinaloa, Mexico. In August and September 2018, morphometric data and biochemical profiles were collected from 33 nesting olive ridley turtles from Ceuta Beach Sanctuary (CBS) and 14 foraging female turtles captured at the foraging site, Navachiste Marine Area (NMA). Nesting turtles sampled had greater CCL (65.86 ± 1.70 cm) than those from the foraging area (61.54 ± 1.22) (p < 0.05). Regarding biochemical profiles, post-nesting turtles had higher packed cell volume (PCV), albumin, blood urea nitrogen (BUN), cholesterol, triglycerides, and calcium than turtles from the foraging area (p < 0.05). Phosphorus levels were higher in foraging turtles than in nesting turtles (p = 0.001), while the remaining parameters showed no significant differences. The present study describes for the first time the blood biochemical values of nesting turtles from the Ceuta Beach Sanctuary in southern Sinaloa, Mexico, similar to those of foraging turtles from the north of the state. The significant differences observed between the two analysis groups may be due to the energy reserves and reproductive and nesting activity of the nesting turtles, so the blood biochemistry values described in this study can be used as a standard reference blood value for the olive ridley turtle population of Sinaloa, Mexico.

Distribution and virulence of Escherichia coli harboring cyclomodulins and supplementary virulence genes isolates from clinical and environmental samples.

This study aimed to determine the prevalence of cyclomodulins (cdt, cnf, pks and cif) in Escherichia coli (E. coli) isolated from clinical and environmental samples, the presence of supplementary virulence genes (SVG), antibiotic resistance, and in vitro cytotoxicity. 413 E. coli were isolated from clinical (stool from obese subjects, normal weight subjects, children with diarrhea, and children without diarrhea; and urine from pregnant and non-pregnant women with urinary tract infections) and environmental (water and different foods) samples. PCR was performed to identify E. coli pathotypes, the four cyclomodulins, and 18 SVG; virulence score, cytotoxic assay, and antibiotic resistance assay were performed. Fifteen percent of E. coli were positive for cyclomodulins and were found in all isolation sources; however, in children with diarrhea, they were more frequent. The most frequent cyclomodulin was cdt. More DEC strains harbor cyclomodulins than non-DEC, and cyclomodulins were most frequent among aEPEC pathotype. SVG ehaC was associated with cyclomodulin-positive strains. Cyclomodulin-positive E. coli had a higher virulence score but no significant cytotoxic activity. They were slightly more resistant to antibiotics. In conclusion, cyclomodulins-positive E. coli was widely distributed in humans, food, and the environment, and they were associated with SVG ehaC, suggesting that these genes may play a role in the pathogenesis of the cyclomodulins. However, more research is needed.

Association of PCSK1 and PPARG1 Allelic Variants with Obesity and Metabolic Syndrome in Mexican Adults.

Metabolic diseases, including obesity, diabetes, and metabolic syndrome, are among the most important public health challenges worldwide. Metabolic diseases are classified as multifactorial diseases in which genetic variants such as single-nucleotide polymorphisms (SNPs) may play an important role. The present study aimed to identify associations linking allelic variants of the PCSK1, TMEM18, GPX5, ZPR1, ZBTB16, and PPARG1 genes with anthropometric and biochemical traits and metabolic diseases (obesity or metabolic syndrome) in an adult population from northwestern Mexico. METHODS: Blood samples were collected from 523 subjects, including 247 with normal weight, 276 with obesity, and 147 with metabolic syndrome. Anthropometric and biochemical characteristics were recorded, and single-nucleotide polymorphisms (SNPs) were genotyped by real-time PCR. RESULTS: PCSK1 was significantly (p < 0.05) associated with BMI, weight, and waist-to-hip ratio; TMEM18 was significantly associated with systolic blood pressure and triglyceride levels; GPX5 was significantly associated with HDL cholesterol levels. In addition, PCSK1 was associated with obesity (p = 1.0 × 10-4) and metabolic syndrome (p = 3.0 × 10-3), whereas PPARG1 was associated with obesity (p = 0.044). CONCLUSIONS: The associations found in this study, mainly between allelic variants of PCSK1 and metabolic traits, obesity, and metabolic syndrome, may represent a risk for developing metabolic diseases in adult subjects from northwestern Mexico.

Antitumor activity of bovine lactoferrin and its derived peptides against HepG2 liver cancer cells and Jurkat leukemia cells.

Liver cancer and leukemia are the fourth and first causes, respectively, of cancer death in children and adults worldwide. Moreover, cancer treatments, although beneficial, remain expensive, invasive, toxic, and affect the patient's quality of life. Therefore, new anticancer agents are needed to improve existing agents. Because bovine lactoferrin (bLF) and its derived peptides have antitumor properties, we investigated the anticancer effect of bLF and LF peptides (LFcin17-30, LFampin265-284 and LFchimera) on liver cancer HepG2 cells and leukemia Jurkat cells. HepG2 and Jurkat cells were incubated with bLF and LF peptides. Cell proliferation was quantified by an MTT assay, and cell morphology and damage were visualized by light microscopy or by phalloidin-TRITC/DAPI staining. The discrimination between apoptosis/necrosis was performed by staining with Annexin V-Alexa Fluor 488 and propidium iodide, and the expression of genes related to apoptosis was analyzed in Jurkat cells. Finally, the synergistic interaction of bLF and LF peptides with cisplatin or etoposide was assessed by an MTT assay and the combination index. The present study demonstrated that bLF and LF peptides inhibited the viability of HepG2 and Jurkat cells, inducing damage to the cell monolayer of HepG2 cells and morphological changes in both cell lines. bLF, LFcin17-30, and LFampin265-284 triggered apoptosis in both cell lines, whereas LFchimera induced necrosis. These results suggested that bLF and LF peptides activate apoptosis by increasing the expression of genes of the intrinsic pathway. Additionally, bLF and LF peptides synergistically interacted with cisplatin and etoposide. In conclusion, bLF and LF peptides display anticancer activity against liver cancer and leukemia cells, representing an alternative or improvement in cancer treatment.

Vibrio parahaemolyticus Is Associated with Diarrhea Cases in Mexico, with a Dominance of Pandemic O3:K6 Clones.

In the present study, we conducted surveillance of the V. parahaemolyticus strains present in clinical samples from six geographical regions of Mexico (22 states) from 2004 to 2011. The serotype dominance, virulence genes, presence of pandemic O3:K6 strains, and antibiotic resistance of the isolates were investigated. In total, 144 strains were isolated from the clinical samples. Seven different O serogroups and twenty-five serovars were identified. Most clinical isolates (66%, 95/144) belonged to the pandemic clone O3:K6 (tdh+, toxRS/new+ and/or orf8+) and were detected in 20 of the 22 states. Among the pandemic clones, approximately 17.8% (17/95) of the strains cross-reacted with the antisera for the K6 and K59 antigens (O3:K6, K59 serotype). Other pathogenic strains (tdh+ and/or trh+, toxRS/new-, orf8-) accounted for 26.3%, and the nonpathogenic strains (tdh- and/or trh-) accounted for 7.6%. Antimicrobial susceptibility testing showed that most of the strains were resistant to ampicillin (99.3%) but were sensitive to most tested antibiotics. The level of multidrug resistance was 1.3%. Our results indicate that pandemic O3:K6 is present in most Mexican states, thus, constant surveillance of V. parahaemolyticus strains in diarrhea patients is a public health priority and is useful for conducting risk assessments of foodborne illnesses to prevent V. parahaemolyticus outbreaks. Overall, our observations indicate that the pandemic O3:K6 clone of V. parahaemolyticus has become a relatively stable subpopulation and may be endemically established in Mexico; therefore, constant surveillance is needed to avoid new outbreaks of this pathogen.

Epidemiological and clinical characteristics of pregnant women and neonates with COVID-19 in Northwest Mexico.

INTRODUCTION: The SARS-CoV-2 virus, which causes COVID-19, has spread quickly worldwide, causing millions of cases and thousands of deaths. Some risk factors in the general population are related to the development of severe COVID-19 or death, but in pregnant women and neonates, the information is limited. OBJECTIVE: To determine the epidemiological and clinical characteristics of pregnant women and neonates diagnosed with COVID-19 by RT-PCR and serological tests, and analyze the relationship between the influenza vaccination and COVID-19 symptoms in infected pregnant women in Sinaloa state. METHODS: We collected samples from 116 pregnant women and 84 neonates from the Women´s Hospital of Sinaloa. They were diagnosed with COVID-19 by RT-PCR and serological tests (IgG), and sociodemographic, clinical and laboratory parameters were recorded. RESULTS: A total of 11.2% (13/116) of the pregnant women were RT-PCR+, 25% (29/116) were IgG+ and 4.3% (5/116) were positive for both tests. Symptoms such as rhinorrhea (P = .04), cough (P = .02) and polypnea (P = .04) in pregnant women were related to COVID-19, also leukocyte index was higher in pregnant women with COVID-19 (P = .03), but the associations were lost after the Bonferroni correction. No laboratory parameters or underlying diseases were associated with COVID-19, and most infected pregnant women had mild cases. We found an association between the influenza vaccine and less common COVID-19 symptoms in pregnant women who were infected (P = .01). A total of 7.2% (6/84) of neonates were RT-PCR+, 35.7% (30/84) were IgG+, and there were no symptoms or underlying diseases associated with neonates who were infected. In conclusion, this work demonstrated that some symptoms were related to COVID-19, most pregnant women and neonates had mild cases, and the influenza vaccine could decrease the severity of COVID-19 cases in pregnant women.

ISOLATION, CHARACTERIZATION, AND ANTIMICROBIAL SUSCEPTIBILITY OF BACTERIA ISOLATED FROM SEA LION (ZALOPHUS CALIFORNIANUS) PUPS IN NORTHWESTERN MEXICO.

Bacterial infections have been documented in marine mammals for decades, and some are considered emerging pathogens with zoonotic potential. The aerobic oral (n=16) and rectal (n=17) bacterial microbiota and their antimicrobial resistance were characterized for 17 apparently healthy California sea lion pups (Zalophus californianus) captured with a hoop net in Farallon Island, Sinaloa, Mexico, in 2016. Bacteriologic cultures, Analytical Profile Index, and PCR were used to identify bacterial species. The Escherichia coli phylogenetic groups were identified by PCR, Salmonella serotypes were identified, and resistance to antibiotics was evaluated. Overall, 39 bacterial species were isolated, including E. coli and Salmonella spp. (35.9% each) and Pseudomonas aeruginosa (28.2%). For E. coli, UNKNOWN phylogroup was the most prevalent (57.7%), followed by the A phylogroup (37.1%). Most Salmonella serotypes were identified as Newport (92.8%); serotype Saintpaul was also identified (7.2%). Sea lions with bacterial co-colonization included 24.2%, from which two bacterial species were isolated, and 3% with three species. Overall, 59% of bacteria were resistant to at least one antibiotic tested, and 25.6% were extensively drug resistant. Bacteria were highly resistant to ampicillin and cefotaxime. This study demonstrates the importance of characterizing the microbiome of sea lions, and the potential effect of pathogens with antimicrobial resistance on wildlife conservation and public health.

Association of FTO, ABCA1, ADRB3, and PPARG variants with obesity, type 2 diabetes, and metabolic syndrome in a Northwest Mexican adult population.

AIM: To identify associations among allelic variants of the genes FTO, ABCA1, ADRB3, and PPARG with anthropometric and biochemical traits, metabolic diseases (obesity, T2D or metabolic syndrome) in an adult population from Northwest Mexico. METHODS: Blood samples were collected from 846 subjects including 266 normal weight subjects, 285 with obesity, and 295 with T2D. Of the 846 persons in the study, 365 presented metabolic syndrome diagnostic criteria. Anthropometric and biochemical traits were recorded and 4 single nucleotide polymorphisms (SNPs): FTO rs9939609 A-allele, ABCA1 rs9282541 A-allele, ADRB3 rs4994 G-allele, and PPARG rs1801282 G-allele were genotyped by real-time PCR. RESULTS: FTO rs9939609 A-allele was significantly associated with obesity (p: 8.3 × 10-4), and metabolic syndrome (p: 0.001), but no individual SNPs were significantly associated with T2D. Finally, the cumulative risk of the four SNPs was significantly associated with obesity (p: 1.95 × 10-4). CONCLUSION: Associations in FTO, ABCA, ADRB3, and PPARG SNPs presented in this study with obesity and metabolic syndrome could represent a risk for developing metabolic diseases in Northwest Mexican adult subjects.

Non-diarrheagenic and diarrheagenic E. coli carrying supplementary virulence genes (SVG) are associated with diarrhea in children from Mexico.

Escherichia coli strains, including diarrheagenic E. coli (DEC), are among the most important causes of childhood diarrhea in developing countries. Since these strains also colonize healthy children, additional factors leading to diarrhea remains to be discovered. We therefore conducted a comprehensive study to investigate if supplementary virulence genes (SVG) carried by DEC strains and non-DEC strains, contribute to diarrhea in Mexican children. E. coli strains were isolated from n = 317 children between 6 and 12 years, n = 114 with diarrhea and n = 203 asymptomatic children from Northwestern Mexico, PCR was used to identify SVG, then virulence score and cytotoxic assay in HT-29 cells were performed to evaluate virulence of E. coli strains. DEC prevalence was 18.6% and its presence was significantly associated with diarrhea cases. aEPEC, tEAEC, ETEC, DAEC, aEAEC, tEPEC, and EIEC pathotypes were identified. aEPEC strains were significantly associated with asymptomatic children, whereas ETEC was only identified in children with diarrhea. E. coli strains carrying colonization-related SVG and/or proteolysis-related SVG were significantly associated with diarrhea. DEC strains were associated to diarrhea if strains carried SVG ehaC, kps, nleB, and/or espC. Virulence score was significantly higher in E. coli from diarrhea cases than asymptomatic. In addition, DEC strains carrying SVG+ were more virulent, followed by non-DEC SVG+ strains, and correlated with the cytotoxicity assay. Nearly 50% of DEC strains were MDR, and ~10% were XDR. In conclusion the findings of this work provide evidence that the presence of E. coli strains (regardless if strains are DEC or non-DEC) with SVG were associated with diarrhea in Mexican children.

Analysis of Epidemiological and Clinical Characteristics of COVID-19 in Northwest Mexico and the Relationship Between the Influenza Vaccine and the Survival of Infected Patients.

The first cases of unexplained pneumonia were reported in Wuhan, China, in December of 2019. Later, a novel coronavirus (SARS-CoV-2) was identified as the causal agent of pneumonia. This virus has since spread to more than 180 countries and has been declared a pandemic by the World Health Organization. Herein, we aimed to determine the epidemiological and clinical characteristics of symptomatic patients with coronavirus disease 2019 (COVID-19) and the relationship between the influenza vaccine with a lower risk of severe COVID-19 infection in the state of Sinaloa. We collected demographic and clinical data of 4,040 patients with acute respiratory infections across Sinaloa state hospitals from February 28 to May 15, 2020. The prevalence of COVID-19 among hospitalized patients with respiratory symptoms in Sinaloa showed 45.2% of men were more affected than women (p < 0.001), and people aged 40-49 years were the most affected. The main symptoms of COVID-19 infection were cough and fever (p < 0.001), while hypertension, obesity, and type 2 diabetes were the chronic diseases associated with COVID-19 than non-COVID-19 (p < 0.003). Healthcare workers were most likely to be infected compared to other occupations (p < 0.001). The general lethality rate was 14.1%, and males >62 years were the ones who had a higher lethality rate (p < 0.001); the aforementioned chronic diseases were related to higher lethality of COVID-19 (p < 0.001). Likewise, higher lethality was seen in housewives and patient retirees/pensioners compared with other occupations (p < 0.001). Finally, we found there was a relationship between influenza vaccination and a lower risk of severe COVID-19 infection and mortality (p < 0.001). These findings showed that healthcare workers, men >62 years with chronic diseases, and retired people were most affected. Furthermore, the influenza vaccine could decrease the severeness of COVID-19 cases.

Essential and trace metals in a post-nesting olive ridley turtles (Lepidochelys olivacea) in Ceuta beach, Sinaloa, Mexico.

Trace metals have been found in sea turtle blood and tissues and may represent a threat to these endangered species. Essential trace metal (Cu, Zn Cd, Pb, As, and Hg) concentrations were determined in blood of adult female, post-nesting olive ridley turtles Lepidochelys olivacea (n = 35) on Ceuta beach, Sinaloa, Mexico. Essential metals (Zn and Cu) analyzed were found in higher concentrations than toxic metals (Cd and Pb), while As and Hg concentrations were below the limits of detection (0.01 µg g-1). Low Pb concentrations (0.09 µg g-1) were previously observed in sea turtles in the Gulf of California. There were no significant correlations found between curved carapace length (61.00-71.00 ± 2.29) vs metal concentrations (p > 0.05). Cd levels were relatively high when compared to other species and populations of sea turtles worldwide and Cd may represent the greatest risk for sea turtles in the Mexican Pacific. Such concentrations of Cd may pose a further risk to sea turtles through bioaccumulation from the nesting female to offspring which may affect embryo development.

Prevalence of Cyclomodulin-Positive E. coli and Klebsiella spp. Strains in Mexican Patients with Colon Diseases and Antimicrobial Resistance.

Colon diseases, such as colorectal cancer (CRC), are multifactor diseases that affect more than one million people per year; recently, the microbiota has been associated with an etiologic factor, specifically bacterial cyclomodulin positivity (CM+). Unfortunately, there are no studies from Mexico that detail the presence of bacterial CM+ in patients with colon diseases. We therefore performed a comprehensive study to investigate the associations and prevalence of cyclomodulin-positive Diarrheagenic E. coli (DEC), non-DEC, and Klebsiella spp. strains isolated from Mexican subjects with colon diseases. In this work, we analyzed 43 biopsies, 87 different bacteria were isolated, and E. coli was the most frequently noted, followed by Klebsiella spp., and Enterococcus spp. E. coli, non-DEC, and EPEC belonging to phylogroup B2 were the most prevalent. More than 80% of E. coli and Klebsiella were CM+. pks, cdt, cnf, and cif were identified. cdt was associated with non-DEC, cif and its combinations with EPEC, as well as cdt and psk with Klebsiella. Lastly, all the CM+ bacteria were resistant to at least one antibiotic (34% were MDR, and 48% XDR). In conclusion, the high prevalence of bacterial CM+ in colon disease patients suggests that these bacteria play an important role in the genesis of these diseases.

Detection of antimicrobial-resistance diarrheagenic Escherichia coli strains in surface water used to irrigate food products in the northwest of Mexico.

Water contamination by pathogenic bacteria is a global public health problem. Contamination of surface water utilized to irrigate food products, or for human consumption, causes outbreaks of foodborne and waterborne disease. Of these, those caused by diarrheagenic Escherichia coli (DEC) strains present substantial morbidity and mortality. The aim of this study was, therefore, to investigate the microbiological quality of surface water and the presence of DEC strains in different water bodies. A total of 472 water samples were collected from irrigation canal, dam, river, and dike water bodies from January through December 2015 in Sinaloa, a State located in Northwestern Mexico. Our studies demonstrated that 47.0% (222/472) of samples contained thermotolerant coliforms above permissive levels whereas E. coli strains were isolated from 43.6% (206/472). Among these E. coli isolates, DEC strains were identified in 14% (29/206) of samples including in irrigation canal (26/29) and river water (3/29) collected from the northern (83%) and central area (17%). Isolated DEC strains were classified as enteroaggregative E. coli (EAEC) 34.4% (10/29), enteropathogenic E. coli (EPEC) 31.0% (9/29), diffuse adherent E. coli (DAEC) 27.5% (8/29), and enterotoxigenic E. coli (ETEC) 6.8% (2/29). Moreover, 90% of isolated DEC strains exhibited resistance to at least one commonly prescribed antibiotic in Mexico whereas 17% were multi-drug resistant. In conclusion, the presence of DEC strains in surface water represents a potential source for human infection, and thus routine monitoring of DEC in surface water and other indirect affected areas should be considered at northwestern Mexico.

Blood Groups Distribution and Gene Diversity of the ABO and Rh (D) Loci in the Mexican Population.

OBJECTIVE: To determine the frequency and distribution of ABO and Rh (D) antigens and, additionally, investigate gene diversity and the structure of Mexican populations. MATERIALS AND METHODS: Blood groups were tested in 271,164 subjects from 2014 to 2016. The ABO blood group was determined by agglutination using the antibodies anti-A, Anti-B, and Anti-D for the Rh factor, respectively. RESULTS: The overall distribution of ABO and Rh (D) groups in the population studied was as follows: O: 61.82%; A: 27.44%; B: 8.93%; and AB: 1.81%. For the Rh group, 95.58% of people were Rh (D), and 4.42% were Rh (d). Different distributions of blood groups across regions were found; additionally, genetic analysis revealed that the IO and ID allele showed an increasing trend from the north to the center, while the IA and Id allele tended to increase from the center to the north. Also, we found more gene diversity in both loci in the north compared with the center, suggesting population structure in Mexico. CONCLUSION: This work could help health institutions to identify where they can obtain blood products necessary for medical interventions. Moreover, this piece of information contributes to the knowledge of the genetic structure of the Mexican populations which could have significant implications in different fields of biomedicine.

Refractive errors among children, adolescents and adults attending eye clinics in Mexico.

AIM: To assess the proportion of refractive errors in the Mexican population that visited primary care optometry clinics in fourteen states of Mexico. METHODS: Refractive data from 676 856 patients aged 6 to 90y were collected from optometry clinics in fourteen states of Mexico between 2014 and 2015. The refractive errors were classified by the spherical equivalent (SE), as follows: sphere+½ cylinder. Myopia (SE>-0.50 D), hyperopia (SE>+0.50 D), emmetropia (-0.50≤SE≤+0.50), and astigmatism alone (cylinder≥-0.25 D). A negative cylinder was selected as a notation. RESULTS: The proportion (95% confidence interval) among all of the subjects was hyperopia 21.0% (20.9-21.0), emmetropia 40.7% (40.5-40.8), myopia 24.8% (24.7-24.9) and astigmatism alone 13.5% (13.4-13.5). Myopia was the most common refractive error and frequency seemed to increase among the young population (10 to 29 years old), however, hyperopia increased among the aging population (40 to 79 years old), and astigmatism alone showed a decreasing trend with age (6 to 90y; from 19.7% to 10.8%). There was a relationship between age and all refractive errors (approximately 60%, aged 50 and older). The proportion of any clinically important refractive error was higher in males (61.2%) than in females (58.3%; P<0.0001). From fourteen states that collected information, the proportion of refractive error showed variability in different geographical areas of Mexico. CONCLUSION: Myopia is the most common refractive error in the population studied. This study provides the first data on refractive error in Mexico. Further programs and studies must be developed to address the refractive errors needs of the Mexican population.

Bovine Lactoferrin and Lactoferrin-Derived Peptides Inhibit the Growth of Vibrio cholerae and Other Vibrio species.

Vibrio is a genus of Gram-negative bacteria, some of which can cause serious infectious diseases. Vibrio infections are associated with the consumption of contaminated food and classified in Vibrio cholera infections and non-cholera Vibrio infections. In the present study, we investigate whether bovine lactoferrin (bLF) and several synthetic peptides corresponding to bLF sequences, are able to inhibit the growth or have bactericidal effect against V. cholerae and other Vibrio species. The antibacterial activity of LF and LF-peptides was assessed by kinetics of growth or determination of colony forming unit in bacteria treated with the peptides and antibiotics. To get insight in the mode of action, the interaction between bLF and bLF-peptides (coupled to FITC) and V. cholera was evaluated. The damage of effector-induced bacterial membrane permeability was measured by inclusion of the fluorescent dye propidium iodide using flow cytometry, whereas the bacterial ultrastructural damage in bacteria treated was observed by transmission electron microscopy. The results showed that bLF and LFchimera inhibited the growth of the V. cholerae strains; LFchimera permeabilized the bacteria which membranes were seriously damaged. Assays with a multidrug-resistant strain of Vibrio species indicated that combination of sub-lethal doses of LFchimera with ampicillin or tetracycline strongly reduced the concentration of the antibiotics to reach 95% growth inhibition. Furthermore, LFchimera were effective to inhibit the V. cholerae counts and damage due to this bacterium in a model mice. These data suggest that LFchimera and bLF are potential candidates to combat the V. cholerae and other multidrug resistant Vibrio species.

Surveillance of Diarrheagenic Escherichia coli Strains Isolated from Diarrhea Cases from Children, Adults and Elderly at Northwest of Mexico.

Diarrheagenic Escherichia coli (DEC) strains are a main cause of gastrointestinal disease in developing countries. In this study we report the epidemiologic surveillance in a 4-year period (January 2011 to December 2014) of DEC strains causing acute diarrhea throughout the Sinaloa State, Mexico. DEC strains were isolated from outpatients of all ages with acute diarrhea (N = 1,037). Specific DEC pathotypes were identified by PCR-amplification of genes encoding virulence factors. The adhesion phenotype and antibiotic resistance were also investigated. DEC strains were detected in 23.3% (242/1037) of cases. The most frequently DEC strain isolated was EAEC [(12.2%), 126/242] followed by EPEC [(5.1%), 53/242], ETEC [(4.3%), 43/242] DAEC [(1.4%), 15/242], STEC [(0.3%), 3/242], and EIEC [(0.2%), 2/242]. EHEC strains were not detected. Overall DEC strains were more prevalent in children ≤2 years of age with EPEC strains the most common of DEC pathotypes. While ∼65% of EAEC strains were classified as typical variant based on the aggregative adherence to in vitro cultures of HEp-2 cells, a high proportion of EPEC strains was classified as atypical strains. EAEC, EPEC, ETEC, and DAEC strains were distributed in the north, central and south regions of Sinaloa state. Among all DEC strains, >90% were resistant to at least one commonly prescribed antibiotic. Strains were commonly resistant to first-line antibiotics such as tetracycline, ampicillin, and sulfamethoxazole-trimethoprim. Furthermore, more than 80% of DEC isolates were multi-drug resistant and EPEC and DAEC were the categories with major proportion of this feature. In conclusion, in nearly one out of four cases of acute diarrhea in Northwestern Mexico a multi-drug resistant DEC strain was isolated, in these cases EAEC was the most prevalent (52%) pathotype.

Strategies of Vibrio parahaemolyticus to acquire nutritional iron during host colonization.

Iron is an essential element for the growth and development of virtually all living organisms. As iron acquisition is critical for the pathogenesis, a host defense strategy during infection is to sequester iron to restrict the growth of invading pathogens. To counteract this strategy, bacteria such as Vibrio parahaemolyticus have adapted to such an environment by developing mechanisms to obtain iron from human hosts. This review focuses on the multiple strategies employed by V. parahaemolyticus to obtain nutritional iron from host sources. In these strategies are included the use of siderophores and xenosiderophores, proteases and iron-protein receptor. The host sources used by V. parahaemolyticus are the iron-containing proteins transferrin, hemoglobin, and hemin. The implications of iron acquisition systems in the virulence of V. parahaemolyticus are also discussed.

Isolation, characterization, and antibiotic resistance of Vibrio spp. in sea turtles from Northwestern Mexico.

The aerobic oral and cloacal bacterial microbiota and their antimicrobial resistance were characterized for 64 apparently healthy sea turtles captured at their foraging grounds in Ojo de Liebre Lagoon (OLL), Baja California Sur (BCS), Mexico (Pacific Ocean) and the lagoon system of Navachiste (LSN) and Marine Area of Influence (MAI), Guasave, Sinaloa (Gulf of California). A total of 34 black turtles (Chelonia mydas agassizii) were sampled in OLL and eight black turtles and 22 olive ridley turtles (Lepidochelys olivacea) were sampled in LSN and MAI, respectively from January to December 2012. We isolated 13 different species of Gram-negative bacteria. The most frequently isolated bacteria were Vibrio alginolyticus in 39/64 (60%), V. parahaemolyticus in 17/64 (26%), and V. cholerae in 6/64 (9%). However, V. cholerae was isolated only from turtles captured from the Gulf of California (MAI). Among V. parahaemolyticus strains, six O serogroups and eight serovars were identified from which 5/17 (29.4%) belonged to the pathogenic strains (tdh (+) gene) and 2/17 (11.7%) had the pandemic clone (tdh (+) and toxRS/new (+)). Among V. cholerae strains, all were identified as non-O1/non-O139, and in 4/6 (66%) the accessory cholera enterotoxin gene (ace) was identified but without virulence gene zot, ctxA, and ctxB. Of the isolated V. parahaemolyticus, V. cholerae, and V. alginolyticus strains, 94.1, 33.4, and 100% demonstrated resistance to at least one commonly prescribed antibiotic (primarily to ampicillin), respectively. In conclusion, the presence of several potential (toxigenic) human pathogens in sea turtles may represent transmission of environmental microbes and a high-risk of food-borne disease. Therefore, based on the fact that it is illegal and unhealthy, we discourage the consumption of sea turtle meat or eggs in northwestern Mexico.