Changes in dominant Escherichia coli and antimicrobial resistance after 24 hr in fecal matter.

Intestinal bacteria carry antimicrobial resistance (AMR) genes in mobile genetic elements which have the potential to spread to bacteria in other animal hosts including humans. In fecal matter, Escherichia coli can continue to multiply for 48 hr after being excreted, and in certain environments, E. coli survive long periods of time. It is unclear the extent to which AMR in E. coli changes in the environment outside of its host. In this study, we analyzed changes in the population structure, plasmid content, and AMR patterns of 30 E. coli isolates isolated from 6 chickens (cloacal swabs), and 30 E. coli isolates from fecal samples (from the same 6 chickens) after 24 hr of incubation. Clonality of isolates was screened using the fumC gene sequence and confirmed in a subset of isolates (n = 14) by multi-locus sequence typing. Major shifts in the population structure (i.e., sequence types) and antibiotic resistance patterns were observed among the numerically dominant E. coli isolates after 24 hr. Four E. coli clones isolated from the cloaca swabs and the corresponding fecal samples (after 24 hr incubation) showed different antibiotic resistance patterns. Our study reveals that fecal matter in the environment is an intermediate habitat where rapid and striking changes occur in E. coli populations and antibiotic resistance patterns

Characterization of the periplasmic flagella proteins of Leptospira spp and cloning of a related gene

The structure and composition of periplasmic flagella (PF) of Leptospira interrogans were analyzed. Electron microscopic observations showed that leptospiral PFs are complex structures composed of an 11.3 nm diameter core and two sheaths. Image analysis revealed sheathed PFs with two different diameters; one of 21.5 nm diameter and the other 42 nm diameter. Two dimensional protein electrophoresis of purified PFs demonstrated the presence of at least seven proteins. The molecular masses of the PF proteins ranged from 31.5 kDa to 36 kDa. Monoclonal antibodies against PF proteins and polyclonal antibodies against gel-purified PF proteins were developed. Immunoelectron microscopy studies demonstrated that a 36 kDa protein was associated with one of the PF sheaths (21.5 nm diameter filament) whereas two antigenically related proteins, the 34 kDa and 35.5 kDa, are located in the core of the leptospiral PF. The 34 kDa and the 35.5 kDa proteins had similar isoelectric point and their N-termini had amino acid sequence homology to PF core proteins found in other spirochetes. These two proteins were named FlaB1 and FlaB2, respectively. Monoclonal antibodies against a major 31.5 kDa PF proteins (MoAb 4A9) did not bind a visible PF structure. A DNA library of L. borgpetersenii DNA was constructed using gt11 as the vector. The library was screened with a pool of monoclonal antibodies against L. interrogans PF. Fifteen reactive plaques were selected. All the clones appeared to react with MoAb 4A9, which recognizes at least 5 L. borgpetersenii PF proteins. Southern blot analysis and DNA sequence analysis separated the clones into 4 groups. One of the clones, expressing the largest fusion protein, was chosen for further analysis. Nucleotide sequences flanking the original clone were obtained and sequenced. An open reading frame (ORF) of 604 bases was observed. The amino acid sequence derived from the DNA analysis showed similarity to an Escherichia coli signal peptidase SppA and to an uncharacterized ORF found near the Haemophilus influenzae lic-1 locus

Microbial community composition in petroleum-contaminated and uncontaminated soil from Francisco de Orellana, in the northern Ecuadorian Amazon

The microbial compositions of two soils from the northern Ecuadorian Amazon (Francisco de Arellana province), one contaminated with petroleum and the other uncontaminated, were compared. Classical culture and moleculartechniques were used to analyze microbial diversity. The cultivable Bacteria from contaminated soil belonged to betapro-teobacteria (16.6%), gammaproteobacteria (66.6%), and Firmicutes (16,6%), whereas in uncontaminated soil, cultivable Bacteria were identified as gammaproteobacteria (80%) and Firmicutes (20%). Analysis of the 16S rRNA showed that in thecontaminated soil proteobacterial populations (alpha-, beta- and deltaproteobacteria) were more abundant than acidobacterialpopulations. The Shannon index (H′ ) was used to estimate diversity in the contaminated and uncontaminated soil. Diversitywas higher in the uncontaminated (H′ = 2.16) than in the contaminated (H′ = 1.72) soil sample. Further studies are neededto determine whether the differences between contaminated and non-contaminated soil samples were due to spontaneousbioremediation microbial activity

Small-Scale Food Animal Production and Antimicrobial Resistance: Mountain, Molehill, or Something in-between?

SummarySmall-scale food animal production is widely practiced around the globe, yet it is often overlooked in terms of the environmental health risks. Evidence suggests that small-scale food animal producers often employ the use of antimicrobials to improve the survival and growth of their animals, and that this practice leads to the development of antimicrobial resistance (AMR) that can potentially spread to humans. The nature of human-animal interactions in small-scale food animal production systems, generally practiced in and around the home, likely augments spillover events of AMR into the community on a scale that is currently unrecognized and deserves greater attention. https://doi.org/10.1289/EHP2116

Detection of Zoonotic Enteropathogens in Children and Domestic Animals in a Semirural Community in Ecuador.

UNLABELLED: Animals are important reservoirs of zoonotic enteropathogens, and transmission to humans occurs more frequently in low- and middle-income countries (LMICs), where small-scale livestock production is common. In this study, we investigated the presence of zoonotic enteropathogens in stool samples from 64 asymptomatic children and 203 domestic animals of 62 households in a semirural community in Ecuador between June and August 2014. Multilocus sequence typing (MLST) was used to assess zoonotic transmission of Campylobacter jejuni and atypical enteropathogenic Escherichia coli (aEPEC), which were the most prevalent bacterial pathogens in children and domestic animals (30.7% and 10.5%, respectively). Four sequence types (STs) of C. jejuni and four STs of aEPEC were identical between children and domestic animals. The apparent sources of human infection were chickens, dogs, guinea pigs, and rabbits for C. jejuni and pigs, dogs, and chickens for aEPEC. Other pathogens detected in children and domestic animals were Giardia lamblia (13.1%), Cryptosporidium parvum (1.1%), and Shiga toxin-producing E. coli (STEC) (2.6%). Salmonella enterica was detected in 5 dogs and Yersinia enterocolitica was identified in 1 pig. Even though we identified 7 enteric pathogens in children, we encountered evidence of active transmission between domestic animals and humans only for C. jejuni and aEPEC. We also found evidence that C. jejuni strains from chickens were more likely to be transmitted to humans than those coming from other domestic animals. Our findings demonstrate the complex nature of enteropathogen transmission between domestic animals and humans and stress the need for further studies. IMPORTANCE: We found evidence that Campylobacter jejuni, Giardia, and aEPEC organisms were the most common zoonotic enteropathogens in children and domestic animals in a region close to Quito, the capital of Ecuador. Genetic analysis of the isolates suggests transmission of some genotypes of C. jejuni and aEPEC from domestic animals to humans in this region. We also found that the genotypes associated with C. jejuni from chickens were present more often in children than were those from other domestic animals. The potential environmental factors associated with transmission of these pathogens to humans then are discussed

Cell aggregation: a mechanism of pathogenic Leptospira to survive in fresh water

Transmission of leptospirosis is facilitated by the survival of pathogenic leptospires in moist environments outside their mammalian host. In the present study, the survival mechanisms of Leptospira interrogans serovar Canicola in aqueous conditions and lack of nutrients were investigated. In distilled water, leptospires were able to remain motile for 110 days (pH 7.2). However, when incubated in a semi-solid medium composed of distilled water and 0.5% purified agarose (pH 7.2), they survived 347 days. In this viscous environment, aggregates of live spirochetes were observed. Neither antibiotics (e.g. tetracycline and ampicillin) nor nutrients inhibited leptospiral aggregation. Immunoblot analysis suggested that cells incubated in water down-regulate the expression of LipL31, an inner-membrane protein, but retain expression of other membrane proteins. These studies provide insights into the mechanisms by which pathogenic Leptospira survives for prolonged periods of time in natural aqueous environments, a key stage in the leptospiral lifecycle. [Int Microbiol 2004; 7(1):35–39

Determinants of Childhood Zoonotic Enteric Infections in a Semirural Community of Quito, Ecuador.

Domestic animals in the household environment have the potential to affect a child's carriage of zoonotic enteric pathogens and risk of diarrhea. This study examines the risk factors associated with pediatric diarrhea and carriage of zoonotic enteric pathogens among children living in communities where smallholder livestock production is prevalent. We conducted an observational study of children younger than 5 years that included the analysis of child (n = 306) and animal (n = 480) fecal samples for Campylobacter spp., atypical enteropathogenic Escherichia coli, Shiga toxin-producing E. coli, Salmonella spp., Yersinia spp., Cryptosporidium parvum, and Giardia lamblia. Among these seven pathogens, Giardia was the most commonly identified pathogen among children and animals in the same household, most of which was found in child-dog pairs. Campylobacter spp. was also relatively common within households, particularly among child-chicken and child-guinea pig pairs. We used multivariable Poisson regression models to assess risk factors associated with a child being positive for at least one zoonotic enteric pathogen or having diarrhea during the last week. Children who interacted with domestic animals-a behavior reported by nearly three-quarters of households owning animals-were at an increased risk of colonization with at least one zoonotic enteric pathogen (prevalence ratio [PR] = 1.56, 95% CI: 1.00-2.42). The risk of diarrhea in the last seven days was elevated but not statistically significant (PR = 2.27, CI: 0.91, 5.67). Interventions that aim to reduce pediatric exposures to enteric pathogens will likely need to be incorporated with approaches that remove animal fecal contamination from the domestic environment and encourage behavior change aimed at reducing children's contact with animal feces through diverse exposure pathways

Staphylococcus aureus outbreak in the intensive care unit of the largest public hospital in Quito, Ecuador

Staphylococcus aureus is a frequent cause of nosocomial pneumonia and bacteremia worldwide. Classical and molecular epidemiology approaches were used to study a S. aureus outbreak in the intensive care unit (ICU) of one of the largest public hospitals in Quito. Staphylococcus aureus isolates from 17 patients and 19 potential carriers from the staff were collected from March 2007 to February 2008 and analyzed by pulsed-fi eld gel electrophoresis (PFGE) to determine their clonal relationships. During this period the hospital reported 16 cases of hospital-acquired staphylococcal pneumonia and an apparent outbreak occurred from June to September 2007. DNA from these isolates formed six different PFGE patterns: four clonal groups, and two groups of clonally related isolates. Molecular typing failed to identify any staphylococcal reservoir among staff members. The current study suggested that a staphylococcal outbreak that occurred in the summer of 2007 was caused by different bacterial clones, although some clones were shared by two patients. Historical analysis of the staphylococcal infections in the ICU showed a higher incidence during the summer months, which coincided with the programmed personnel shift. This observation suggests that outbreaks might be produced by the introduction of improperly trained personnel. [Int Microbiol 2013; 16(2):81-86]Keywords: Staphylococcus aureus; staphylococal pneumonia; nosocomial outbreaks; MRS

Dengue Serotype Differences in Urban and Semi-rural Communities in Ecuador

Dengue is a major vector-borne infection causing large outbreaks in urban communities in tropical regions. During the period 2010- 2014; 434 serum samples from febrile patients were collected from a  semi-rural community hospital located in the norwestern region of Ecuador. Dengue virus (DENV) was investigated by reverse transcriptase PCR; a total of 48 samples were positive for dengue. During our study we detected  DENV-2 and DENV-3 from 2010 to 2013 and the four  DENV  serotypes during the period 2013-2014.  Surprisingly, our results contrasted with surveys carried out in urban centers throughout the  Ecuadorian Coast in which  DENV-1, DENV-2 and DENV-4 were prevalent during years 2010-2013 and only 2 serotypes  (DENV-1 and DENV-2) in 2014.These results suggest  that dengue viruses in semi-rural communities didn’t  originate in the Ecuadorian cities.  &nbsp