Pseudomonas aeruginosa epidemic high-risk clones and their association with multidrug-resistant.

BACKGROUND: In Ecuador, data on molecular epidemiology, as well as circulating clones, are limited. Therefore, this study aims to know the population structure of Pseudomonas aeruginosa by identifying clones in clinical samples in Quito-Ecuador. METHODS: A significant set (45) clinical Pseudomonas aeruginosa isolates were selected, including multidrug and non-multidrug resistant isolates, which were assigned to sequence types (STs) and compared with their antibiotic susceptibility profile. The genetic diversity was assessed by applying the multilocus sequence typing (MLST) scheme and the genetic relationships between different STs were corroborated by phylogenetic networks. RESULTS: The MLST analysis identified 24 different STs and the most prevalent STs were ST-3750 and ST-253. The majority of the multidrug-resistance (MDR) isolates were included in ST-3750 and ST-253, also 3 singleton STs were identified as MDR isolates. The 21 different STs were found in non-multidrug resistance (non-MDR) isolates, and only 3 STs were found in more the one isolate. CONCLUSIONS: The population structure of clinical P. aeruginosa present in these isolates indicates a significant association between MDR isolates and the clonal types: all ST-3750 and ST-253 isolates were MDR. ST-3750 is a closely related strain to the clonal complex ST111 (CC111). ST-253 and ST111 are a group of successful high-risk clones widely distributed worldwide. The multiresistant isolates studied are grouped in the most prevalent sequence types found, and the susceptible isolates correspond mainly to singleton sequence types. Therefore, these high-risk clones and their association with multidrug-resistance phenotypes are contributing to the spread of MDR in Quito-Ecuador.

First report of fatal fungemia due Fusarium oxysporum in a patient with COVID-19 in Ecuador.

Filamentous fungal infections are an important cause of systemic infections in immunocompromised patients. Fusarium genus members potentially cause disseminated infections, especially in patients with catheters, due to the ability to adhere to these devices. We describe a case of fatal fungemia due to Fusarium oxysporum in a patient with COVID-19 in Ecuador. The genus identification was carried out with conventional techniques and species identification by molecular and phylogenetic techniques through sequencing of the ITS region.

Dominance of ST131, B2, blaCTX-M-15, and papA-papC-kpsMII-uitA among ESBL Escherichia coli isolated from bloodstream infections in Quito, Ecuador: a 10-year surveillance study (2009-2019).

AIMS: This study aimed to examine antibiotic resistance and the epidemiology of extended-spectrum ß-lactamases (ESBL)-producing Escherichia coli associated with bloodstream infections over a period of 10 years. METHODS AND RESULTS: Isolates were collected from January 2009 to December 2019 and those testing for E. coli were included. Antibiotic susceptibility was tested using the VITEK® system. Selected isolates were further characterized by amplification of marker genes (virulence traits, phylogroups, and sequence types). A total of 166 ESBL-producing E. coli were recovered. The blaCTX-M-15 allele was the most abundant. Most of the isolates were resistant to ceftriaxone, cefepime, ceftazidime, ampicillin/sulbactam, piperacillin/tazobactam, and ciprofloxacin. No resistance to carbapenems was registered. More than 80% of bacteria were classified as extraintestinal pathogenic E. coli (ExPEC), and the combination of virulence traits:papA-papC-kpsMII-uitA was the most common. Phylogroup B2 was the most prevalent, and bacteria predominantly belonged to ST131. CONCLUSIONS: There was an increase in the ExPEC ESBL-E coli in bloodstream infections and the relationship between the isolates found in these infections during these 10 years.

First Report of Antibiotic Resistance Markers cfiA and nim Among Bacteroides fragilis Group Strains in Ecuadorian Patients.

In recent years, increasing resistance of Bacteroides fragilis to several antibiotics has been reported in different countries. The aim of this study was to evaluate the antibiotic resistance profiles of Bacteroides spp. isolated from clinical samples by phenotypic and molecular methods. A total of 40 nonrepetitive isolates of the B. fragilis group were studied from 2018 to 2019. The species was identified by API 20A system. The minimum inhibitory concentrations (MICs) were determined by Sensititre anaerobe MIC plate. The presence of the nim and cfiA genes was checked by conventional PCR. The association between genes and insertion sequence (IS) was performed by whole genome sequencing. Eleven isolates were categorized as metronidazole-resistant and only 2 isolates harbored the nim gene. Five isolates were imipenem-resistant, but cfiA gene was detected in two isolates. cfiA gene was closely related to the cfiA-4 allele and associated with IS614B. The nim gene was not related to any nim gene type and was considered a new variant named nimL. IS612 was found upstream of nimL gene. In view of the scarcity of data on B. fragilis, there is a need to surveil antibiotic resistance levels and molecular mechanisms to implement better antimicrobial therapies against this important group of bacteria.

Mutations associated with Helicobacter pylori antimicrobial resistance in the Ecuadorian population.

AIMS: We described the presence of Helicobacter pylori (HP) and estimated the prevalence of primary and secondary resistance using molecular detection in gastric biopsies of Ecuadorian patients. METHODS AND RESULTS: 66.7% (238/357) of the patients demonstrated the presence of HP using CerTest qPCR. Of these, 69.79% (104/149) were without previous HP eradication treatment and 64.42% (134/208) with prior HP eradication treatment. The mutation-associated resistance rate for clarithromycin was 33.64% (primary resistance) and 32.82% (secondary resistance), whereas that in levofloxacin the primary and secondary resistance was 37.38% and 42%, respectively. For tetracycline and rifabutin, primary and secondary resistance was 0%. Primary and secondary resistance for metronidazole and amoxicillin could not be evaluated by genotypic methods (PCR and sequencing). CONCLUSIONS: The analysis of mutations in gyrA, 23S rRNA and 16S rRNA is useful to detect bacterial resistance as a guide for eradication therapy following failure of the first-line regimen. SIGNIFICANCE AND IMPACT OF THE STUDY: This study carried out in an Ecuadorian population indicates that the resistance of HP to first-line antibiotics is high, which may contribute to the high rates of treatment failure, and other treatment alternatives should be considered.

Genomic epidemiology of SARS-CoV-2 transmission lineages in Ecuador.

Characterisation of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) genetic diversity through space and time can reveal trends in virus importation and domestic circulation and permit the exploration of questions regarding the early transmission dynamics. Here, we present a detailed description of SARS-CoV-2 genomic epidemiology in Ecuador, one of the hardest hit countries during the early stages of the coronavirus-19 pandemic. We generated and analysed 160 whole genome sequences sampled from all provinces of Ecuador in 2020. Molecular clock and phylogeographic analysis of these sequences in the context of global SARS-CoV-2 diversity enable us to identify and characterise individual transmission lineages within Ecuador, explore their spatiotemporal distributions, and consider their introduction and domestic circulation. Our results reveal a pattern of multiple international importations across the country, with apparent differences between key provinces. Transmission lineages were mostly introduced before the implementation of non-pharmaceutical interventions, with differential degrees of persistence and national dissemination.

Genomic epidemiology of SARS-CoV-2 transmission lineages in Ecuador.

Characterisation of SARS-CoV-2 genetic diversity through space and time can reveal trends in virus importation and domestic circulation, and permit the exploration of questions regarding the early transmission dynamics. Here we present a detailed description of SARS-CoV-2 genomic epidemiology in Ecuador, one of the hardest hit countries during the early stages of the COVID-19 pandemic. We generate and analyse 160 whole genome sequences sampled from all provinces of Ecuador in 2020. Molecular clock and phylgeographic analysis of these sequences in the context of global SARS-CoV-2 diversity enable us to identify and characterise individual transmission lineages within Ecuador, explore their spatiotemporal distributions, and consider their introduction and domestic circulation. Our results reveal a pattern of multiple international importations across the country, with apparent differences between key provinces. Transmission lineages were mostly introduced before the implementation of non-pharmaceutical interventions (NPIs), with differential degrees of persistence and national dissemination.

Evidence of SARS-CoV-2 reinfection within the same clade in Ecuador: A case study.

OBJECTIVES: To date, reported SARS-CoV-2 reinfection cases are mainly from strains belonging to different clades. As the pandemic advances, a few lineages have become dominant in certain areas leading to reinfections by similar strains. Here, we report a reinfection case within the same clade of the initial infection in a symptomatic 28-year-old-male in Quito-Ecuador. METHODS: Infection was detected by reverse transcription-polymerase chain reaction, and immune response evaluated by antibody testing. Whole-genome sequencing was performed and phylogenetic analysis conducted to determine relatedness. RESULTS: Both the infection and the reinfection strains were assigned as Nextstrain 20B, Pangolin lineage B.1.1 and GISAID clade O. Our analysis indicated 4-6 fold more nucleotide changes than are expected for reactivation or persistence compared with the natural rate of SARS-CoV-2 mutation (∼2-3 nucleotide changes per month), thus supporting reinfection. Furthermore, approximately 3 months after the second infection, COVID-19 antibodies were not detectable in the patient, suggesting potential vulnerability to a third infection. CONCLUSIONS: Our results showed evidence of SARS-CoV-2 reinfection within the same clade in Ecuador, indicating that previous exposure to SARS-CoV-2 does not guarantee immunity in all cases.

Antibiotic resistance of Salmonella strains from layer poultry farms in central Ecuador.

AIMS: This study evaluated the antimicrobial resistance of Salmonella enterica strains from layer poultry farms in central Ecuador isolated during 2017. This geographical area is responsible for around 60% of total domestic egg production, yet, as of 2019, no reports had been published on the phenotypic and genotypic antibiotic resistance patterns of Salmonella in the layer poultry farms of this area. METHODS AND RESULTS: Thirty-one isolates from layer poultry farms in central Ecuador obtained during 2017 were evaluated. The resistance profiles exhibited considerable differences in serovar and sample origin, grouping into nine clades by phenotype. S. Infantis strains were of the MDR phenotype in 94·4% of isolates. S. Typhimurium strains were of a reduced antimicrobial resistance phenotype and 50% showed resistance to one antimicrobial compound. One of the S. enterica nontyped strains had an MDR profile to 11 of the 20 antibiotics evaluated (eight groups). And the two remaining S. enterica nontyped strains showed resistance to two and three antibiotics respectively. The ESBL phenotype, which is resistant to clinically notable antibiotics such as ceftriaxone, ampicillin and cefepime, was observed only in S. Infantis (15/18). These strains harbour the emerging blaCTX-M-65 gene, and co-harbour tetA and sul1 resistance genes in four strains. Additional ß-lactamase genes, carbapenemase-producing genes (blaIMP, blaVIM , blaOXA48 , blaKPC , blaNDM ) and colistin-mobile resistance gene mcr-1 were not detected. CONCLUSIONS: The findings highlight the potential role of layer poultry farm environments in central Ecuador as reservoirs of MDR Salmonella strains. SIGNIFICANCE AND IMPACT OF THE STUDY: These results suggest the necessity of reinforcing biosecurity practices to reduce the probability of transmission of MDR Salmonella across the food chain.

Draft Genome Sequence of a Metronidazole-Resistant Bacteroides fragilis Strain Isolated in Ecuador.

Here, we report the draft genome sequence of Bacteroides fragilis strain Z&Z143, a metronidazole-resistant bacterium isolated from a blood culture from an Ecuadorian patient hospitalized in a medical institution in Quito, Ecuador. We describe a new variant of the nim genes, which is associated with metronidazole resistance.

High prevalence of B2-ST131 clonal group among extended-spectrum ß-lactamase-producing Escherichia coli isolated from bloodstream infections in Quito, Ecuador.

OBJECTIVES: The purpose of this study was to describe the clonal relationships and phylogroups of extended-spectrum ß-lactamase-producing Escherichia coli (ESBL-Ec) isolated from patients with bacteraemia in three hospitals in Quito, Ecuador. METHODS: Between June 2013 and September 2014, a total of 4354 blood cultures were performed in three hospitals located in different areas of Quito. A BACTECTM system was used for blood culture, and the VITEK®2 system was used for species identification and in vitro antimicrobial susceptibility testing. The ESBL genotype, presence of the blaCTX-M, blaTEM and blaSHV genes, and the phylogenetic group of E. coli isolates was determined by PCR. Clonal groups were established by multilocus sequence typing (MLST). RESULTS: Of 929 blood cultures positive for Gram-negative bacilli, 181 (19.5%) were positive for E. coli, representing the most frequent bacteraemia isolates in each hospital. Of the 181 E. coli isolates, 57 (31.5%) were ESBL-Ec. The main sources of ESBL-Ec bacteraemia were urinary tract infection (40; 70.2%), biliary tract infection (10; 17.5%) and other infections (7; 12.3%). The majority of ESBL-Ec isolates (39; 68.4%) from the three hospitals belonged to the virulent phylogenetic group B2, of which 36/39 (92.3%) were ST131 and 33/36 (91.7%) carried the blaCTX-M-15 gene. CONCLUSION: These results provide knowledge of the phylogenetic relationships of E. coli from bacteraemia in Ecuadorian patients. ST131 has emerged in ESBL-Ec, representing an important public-health problem because this multiresistant clone is considered to be a vehicle for the propagation of antimicrobial resistance genes and is a highly virulent, well-adapted human pathogen.