Diarrheagenic Escherichia coli Strains Recovered from Urban Pigeons (Columba livia) in Brazil and Their Antimicrobial Susceptibility Patterns

Abstract

Urban pigeons (Columba livia) come into close contact with humans and animals, and may contribute to the spread of infectious agents. These may include human pathogens such as diarrheagenic Escherichia coli strains, which are able to survive in pigeon feces, thus creating potential for human exposure and infection. Our objectives were to determine the occurrence of diarrheagenic E. coli strains in fresh feces from urban pigeons and their drug susceptibility patterns. E. coli strains were isolated from 100 fresh feces samples and presumptive phenotypic species identification was carried out, confirmed by amplification of specific 16S ribosomal RNA encoding DNA. Multiplex PCR was performed to characterize pathogenic strains. Drug susceptibility patterns were determined by the agar dilution method. Enteroinvasive E. coli, Shiga toxin-producing E. coli, enteropathogenic E. coli, and enterotoxigenic E. coli were detected at an overall rate of 12.1%. Among the isolated E. coli strains, 62.1% were susceptible to all tested drugs, whereas 37.9% were resistant to at least one of the antimicrobials tested. Amikacin was the less effective drug (36.8% resistance), followed by ampicillin (7.8%). No resistance was detected to gentamicin, ceftriaxone, and ceftazidime and almost all the isolates were susceptible to ampicillin-sulbactam (98.4%), levofloxacin (97.8%), and trimethoprim-sulfamethoxazole (96.1%). Since these pigeons may harbor multidrug-resistant pathogens, their presence in an urban environment could be an important component of infection spread, with impact on public health.

Characterization of the microbial community in a lotic environment to assess the effect of pollution on nitrifying and potentially pathogenic bacteria

“…Our results show that EHEC was genotyped as stx1 + /stx2 + at the urban site; however the stx2 gene was less than the detection limit in the rural area of the study, which is relevant and worrisome since the stx2 gene is believed to be commonly associated with more severe illnesses (Oliveira et al, 2008). An interesting observation is that the same pathotypes were also found in regional studies with urban pigeons and isolates from human diarrheic feces, indicating the circulation of the same genes in different samples from the city of Juiz de Fora (Silva et al, 2009;.…”

Antibiotic resistance in Escherichia coli isolates from roof-harvested rainwater tanks and urban pigeon faeces as the likely source of contamination

“…Bird populations sympatric to areas inhabited by people and areas with a high density of livestock have been reported to be colonised with antibiotic resistant E. coli strains possibly selected by the antibiotic practice in humans and domestic animals (Marques et al 2007;Silva et al 2009). In particular, urban pigeons (Columba livia) come into close contact with humans and other animals, and are considered to be important reservoirs and vectors of pathogenic and antibiotic resistant bacterial strains (Silva et al 2009).…”

“…In particular, urban pigeons (Columba livia) come into close contact with humans and other animals, and are considered to be important reservoirs and vectors of pathogenic and antibiotic resistant bacterial strains (Silva et al 2009). The adaptation of these birds to urban environments, the absence of natural predators and availability of food enables them to multiply extensively and become a significant source of faecal pollution (Marques et al 2007).…”

“…from the weather; (ii) the absence of natural predators; and (iii) availability of food (Silva et al 2009) (Silva et al, 2012). Animal feed lots including those for dairy cows and chicken feed waste provide an abundant source of food to the birds which then multiply extensively and become a significant source of faecal pollution.…”

“…Of these animals birds are the most mobile and have been implicated as reservoirs of antibiotic resistant enteric pathogens (Silva et al 2009). …”