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Abstract Background In Ecuador, cervical cancer is the third most common cancer among women and the second most common cause of cancer-related death in women. Although HPV represents a serious public health problem worldwide, the information about its prevalence and genotypes in remote communities of Ecuador is limited. The aim of this study was to determine the distribution of HPV genotypes among ethnic minority women from two remote communities of the northwestern region of Ecuador: Afro-Ecuadorians and Chachis (Amerindian group). Methods We included 291 women who responded to a short survey and were screened for HPV by the amplification of the L1 gene and a nested multiplex PCR to detect 14 high risk (HR) genotypes. A survey collected information on ethnicity, age, community access, and sexual and gynecological history. We identified risk factors associated with HPV infection and co-infection using multivariate logistic regression to calculate odds ratio (OR) and Wald 95% confidence intervals (CI). Results Overall, HPV prevalence in the study cohort was 56%, and the five most common HR-HPV genotypes were HPV-58, -16, -68, -39, and -43; however, the distribution of HPV genotypes varied according to ethnicity. We identified lineage A (European variant) for HPV-16 and sublineage A2 for HPV-58 in both ethnic groups. Adjusting for ethnicity, age, community access, and number of sexual partners, we found that Afro-Ecuadorian women were less likely to have an HPV infection than Chachi women (OR: 0.49, 95% CI: 0.25, 0.96), and that participants in communities only accessible by river had 64% less chances of an HPV infection when compared to women in communities accessible by road (OR: 0.36, 95% CI: 0.19, 0.71), and women with 2 to 3 sexual partners had 2.47 times the odds of HPV infection than participants with 0–1 partners (OR: 2.47, 95% CI: 1.32, 4.6). Similar associations were observed with prevalence of co-infection. Conclusions This study provides baseline knowledge regarding the prevalence and distribution of HPV genotypes in ethnic groups of the northwestern coastal Ecuador and essential information for the implementation of appropriate HPV testing and vaccination program to prevent cervical cancer.

Listeria monocytogenes is a foodborne pathogen that can produce serious, even fatal, infections. Among other foods, it can be found in unpasteurized dairy and ready-to-eat products. Surveillance of L. monocytogenes is of great interest since sources of infection are difficult to determine due to the long incubation period, and because the symptoms of listeriosis are similar to other diseases. We performed a genomic study of L. monocytogenes isolated from fresh cheeses and clinical samples from Ecuador. Sixty-five isolates were evaluated and sequenced, 14 isolates from cheese samples and 20 from clinical listeriosis cases from the National Institute of National Institute of Public Health Research, and 31 isolates from artisanal cheese samples from 8 provinces. All isolates exhibited heterogeneous patterns of the presence of pathogenicity islands. All isolates exhibited at least 4 genes from LIPI-1, but all references (26 L. monocytogenes closed genomes available in the NCBI database) showed the complete island, which encompasses 5 genes but is present in only two Ecuadorian isolates. Most isolates lacked gene actA. Genes from LIPI-2 were absent in all isolates. LIPI-3 and LIPI-4 were present in only a few references and isolates. With respect to the stress survival islets, our samples either presented SSI-1 or SSI-F2365, except for one isolate that presented SSI-F2365 and also one gene from SSI-1. None of the samples presented SSI-2. The predominant ST (sequence type) was ST2 (84.62% 55/65), and the only ST found in food (93.33% 42/45) and clinical samples (65% 13/20). Isolates were not grouped according to their sampling origin, date, or place in a phylogenetic tree obtained from the core alignment. The presence of ST2 in food and clinical samples, with high genomic similarity, suggests a foodborne infection risk linked to the consumption of fresh cheeses in Ecuador.

Abstract One major health issue is the microbial and chemical contamination of natural freshwater, particularly in Latin American countries, such as Ecuador, where it is still lacking wastewater treatment plants. This study analyzed the water quality in twelve rivers of Ecuador (Coastal, Andean, and Amazonian regions). All rivers showed levels of E. coli and total coliforms above the maximum limit according to International and Ecuadorian legislations. The most polluted rivers were Zamora, Esmeraldas and Machángara. Also, E. coli pathotypes were found in six rivers. Several physicochemical and metal parameters were detected in high levels, such as CODTOTAL (in eight rivers), TSS (in six rivers), TS (in two rivers), Al (in nine rivers), Zn (in eight rivers), Pb (in three rivers), Cu (in three rivers), Fe (in two rivers), and Mn (in Machángara River). Our results agree with other studies in Latin America (such as Colombia, Brazil, and Peru) reporting similar contamination in water resources used for agriculture, livestock, and human consumption. Overall, Guayas, Guayllabamba, and Machángara Rivers showed the highest levels of physicochemical parameters (such as CODTOTAL and TSS) and metal concentrations (such as copper, zinc, aluminum, iron, and manganese). Further studies should evaluate contamination sources and public health impact.

Salmonella enterica subspecies enterica is one of the most important foodborne pathogens and the causative agent of salmonellosis, which affects both humans and animals producing numerous infections every year. The study and understanding of its epidemiology are key to monitoring and controlling these bacteria. With the development of whole-genome sequencing (WGS) technologies, surveillance based on traditional serotyping and phenotypic tests of resistance is being replaced by genomic surveillance. To introduce WGS as a routine methodology for the surveillance of food-borne Salmonella in the region, we applied this technology to analyze a set of 141 S. enterica isolates obtained from various food sources between 2010 and 2017 in the Comunitat Valenciana (Spain). For this, we performed an evaluation of the most relevant Salmonella typing methods, serotyping and sequence typing, using both traditional and in silico approaches. We extended the use of WGS to detect antimicrobial resistance determinants and predicted minimum inhibitory concentrations (MICs). Finally, to understand possible contaminant sources in this region and their relationship to antimicrobial resistance (AMR), we performed cluster detection combining single-nucleotide polymorphism (SNP) pairwise distances and phylogenetic and epidemiological data. The results of in silico serotyping with WGS data were highly congruent with those of serological analyses (98.5% concordance). Multi-locus sequence typing (MLST) profiles obtained with WGS information were also highly congruent with the sequence type (ST) assignment based on Sanger sequencing (91.9% coincidence). In silico identification of antimicrobial resistance determinants and minimum inhibitory concentrations revealed a high number of resistance genes and possible resistant isolates. A combined phylogenetic and epidemiological analysis with complete genome sequences revealed relationships among isolates indicative of possible common sources for isolates with separate sampling in time and space that had not been detected from epidemiological information. As a result, we demonstrate the usefulness of WGS and in silico methods to obtain an improved characterization of S. enterica enterica isolates, allowing better surveillance of the pathogen in food products and in potential environmental and clinical samples of related interest.

Mapping of high-throughput sequencing (HTS) reads to a single arbitrary reference genome is a frequently used approach in microbial genomics. However, the choice of a reference may represent a source of errors that may affect subsequent analyses such as the detection of single nucleotide polymorphisms (SNPs) and phylogenetic inference. In this work, we evaluated the effect of reference choice on short-read sequence data from five clinically and epidemiologically relevant bacteria (Klebsiella pneumoniae, Legionella pneumophila, Neisseria gonorrhoeae, Pseudomonas aeruginosa and Serratia marcescens). Publicly available whole-genome assemblies encompassing the genomic diversity of these species were selected as reference sequences, and read alignment statistics, SNP calling, recombination rates, dN/dS ratios, and phylogenetic trees were evaluated depending on the mapping reference. The choice of different reference genomes proved to have an impact on almost all the parameters considered in the five species. In addition, these biases had potential epidemiological implications such as including/excluding isolates of particular clades and the estimation of genetic distances. These findings suggest that the single reference approach might introduce systematic errors during mapping that affect subsequent analyses, particularly for data sets with isolates from genetically diverse backgrounds. In any case, exploring the effects of different references on the final conclusions is highly recommended.

Salmonella enterica is one of the most important foodborne pathogens around the world. In the last years, S. enterica serovar Infantis has become an important emerging pathogen in many countries, often as multidrug resistant clones. To understand the importance of S. enterica in the broiler industry in Ecuador, we performed a study based on phenotypic and WGS data of isolates from poultry farms, chicken carcasses and humans. We showed a high prevalence of S. enterica in poultry farms (41.4%) and chicken carcasses (55.5%), but a low prevalence (1.98%) in human samples. S. Infantis was shown to be the most prevalent serovar with a 98.2, 97.8, and 50% in farms, foods, and humans, respectively, presenting multidrug resistant patterns. All sequenced S. Infantis isolates belonged to ST32. For the first time, a pESI-related megaplasmid was identified in Ecuadorian samples. This plasmid contains genes of antimicrobial resistance, virulence factors, and environmental stress tolerance. Genomic analysis showed a low divergence of S. Infantis strains in the three analyzed components. The results from this study provide important information about genetic elements that may help understand the molecular epidemiology of S. Infantis in Ecuador.

Soybean is a crop with a national production in Ecuador which is insufficient to meet its demand. Therefore, soybean seeds and soya beans are imported from countries where the use of transgenic soybean has been approved. As a consequence, there is a probability of finding this type of soybean in Ecuadorian territory. In this research, a detection and quantification SYBR Green-based method of genetically modified soybean was standardized. Primers used for the amplification corresponded to specific sequences of the two most representative recombinant elements in GM (genetically modified) crops, the 35S promoter from the Cauliflower Mosaic Virus (P35S) and NOS terminator from Ti plasmid in Agrobacterium tumefaciens (TNOS). These elements generated 200bp and 69bp amplicons respectively. The quantitative analysis was performed generating a standard curve based on the amplification of certified reference materials with 0.01%, 0.1%, 1% y 10% of GM soybean event GTS 40-3-2, using the above mentioned primers. The detection limit was set at 0.01% while the quantification limit was set at 0.1%. In 2 of the 26 soybean samples analyzed, more than 0.1% of GMOs was found (sample 22 with 0.2% and sample 23 with 14%). Additionally, adventitious GMO presence was detected in 8 of the tested samples. Due to Ecuadorian GMO regulations, this kind of analysis is important in order to determine the presence of GMOs in Ecuador, and is clear evidence for the need of trained personnel and specialized institutions for the detection and analysis of GMOs.

Objectives: Burkholderia cepacia has been linked to healthcare-associated infections and colonization caused by contamination of alcohol-free mouthwash used in patients undergoing mechanical ventilation. The purpose of our study was to establish the source of a clustering of healthcare-associated B. cepacia isolates in patients on mechanical ventilation in the intensive care unit (ICU). Methods: During April 2012 the Infection Control Committee became concerned when B. cepacia was isolated from tracheal aspirate cultures of three ICU patients. The medical records for the years 2011 and 2012 were reviewed to identify further cases. Cultures of potential reservoirs were done. Isolates from patients and an alcohol-free mouthwash were submitted to multilocus sequence typing (MLST) analysis and antimicrobial resistance testing. Results: Four patients with positive cultures for B. cepacia were identified before the review of the medical records for the years 2011 and 2012. Nine further cases were identified in the review, defined as a patient with pneumonia who had a culture of respiratory secretions that was positive for B. cepacia. Three were cases of infection and 10 were colonizations. All of the isolates from patients (J, K, L, and M) and mouthwash samples (B19, B20, and B21) were genetically identical by MLST analysis. Conclusions: Our findings strongly suggest that alcohol-free mouthwash solution intrinsically contaminated with B. cepacia was the source of these colonizations and infections involving adults in the ICU.