Antibiotic Resistance Profile of Salmonella sp. Isolates from Commercial Laying Hen Farms in Central-Western Brazil.

Microbial resistance to antibiotics poses a significant threat to both human and animal health, necessitating international efforts to mitigate this issue. This study aimed to assess the resistance profiles of Salmonella sp. isolates and identify the presence of intl1, sul1, and blaTEM resistance genes within antigenically characterized isolates, including Agona, Livingstone, Cerro, Schwarzengrund, Salmonella enterica subsp. enterica serotype O:4.5, Anatum, Enteritidis, Johannesburg, Corvallis, and Senftenberg. These isolates underwent susceptibility testing against 14 antibiotics. The highest resistance percentages were noted for sulfamethoxazole (91%), sulfonamides (51%), and ceftiofur (28.9%), while no resistance was observed for ciprofloxacin. Salmonella Johannesburg and Salmonella Corvallis showed resistance to one antibiotic, whereas other serovars were resistant to at least two. Salmonella Schwarzengrund exhibited resistance to 13 antibiotics. The intl1 gene was detected in six out of the ten serovars, and the sul1 gene in three, always co-occurring with intl1. The blaTEM gene was not identified. Our findings highlight the risk posed by the detected multiple resistances and genes to animal, human, and environmental health. The multidrug resistance, especially to third-generation cephalosporins and fluoroquinolones, highlights the need for stringent monitoring of Salmonella in laying hens. The potential of the environment, humans, eggs, and their products to act as vectors for antibiotic resistance represents a significant concern for One Health.

Fontes de infecção e perfil de suscetibilidade aos antimicrobianos de Salmonella sp. isoladas no fluxo de produção de frangos de corte / Sources of infection and antimicrobial susceptibility profile of Salmonella sp. isolated in broiler production flow

Este trabalho foi desenvolvido com objetivo de pesquisar Salmonella em amostras de fígado, coração, saco da gema e mecônio de pintos de corte de um dia; inglúvios e cecos obtidos em abatedouros e em suabes de arrasto; larvas ou adultos de Alphitobius diaperinus. Complementarmente, determinou-se o perfil de suscetibilidade aos antimicrobianos: amoxicilina (10 mcg), ampicilina (10 mcg), ciprofloxacina (5 mcg), enrofloxacina (5 mcg), florfenicol (30 mcg), neomicina (30 mcg), sulfonamida (300 mcg), tetraciclina (30 mcg) e trimetoprim-sulfametoxazol (25 mcg) dos serovares tipificados isolados. As amostras foram submetidas às análises microbiológicas pelos métodos bacteriológicos convencionais. Salmonella sp. foi isolada em 6,2% (4/64) do fígado, 4,7% (3/64) do coração, 3,1% (2/64) dos sacos da gema e 4,7% (3/64) do mecônio, num total de 4,7% (12/256) (pinto de um dia); em 10,2% (13/128) das amostras ambientais, sendo 9,4% (9/96) de suabes de arrasto 12,5%, (4/32) de larvas e adultos Alphitobius diaperinus e em 4,4% (28/640) das amostras em abatedouros, sendo 6,5% (21/320) dos inglúvios e 2,2% (7/320) dos conteúdos cecais de abatedouro. Salmonella enterica ser. Enteritidis foi identificada em suabes de arrasto e em amostras de Alphitobius diaperinus, enquanto Salmonella enterica ser. Typhimurium foi encontrada nos inglúvios e cecos. Salmonella enterica ser. Enteritidis apresentaram 75% (6/8) de resistência às sulfonamidas e Salmonella enterica ser. Typhimurium 100% (3/3). A amoxicilina foi outro antimicrobiano com elevada frequência de resistência. Adicionalmente, 20,7% (11/53) dos serovares apresentaram resistência simultânea a pelo menos dois princípios ativos. Conclui-se que Salmonella encontra-se amplamente distribuída no fluxo de produção de frangos de corte, e a via vertical continua sendo uma fonte de introdução de Salmonella sp. à cadeia de produção; cama e insetos podem perpetuar e veicular Salmonella de interesse zoonótico no ambiente avícola; a existência de cepas resistentes aos antimicrobianos, bem como a resistência múltipla, constituem ameaça à saúde pública.(AU)

This work aimed at searching for Salmonella in liver, heart, yolk sac and meconium samples of one-day-old chicks, crops and cecum samples from slaughterhouses and drag swabs and Alphitobius diaperinus larvae or adults. It also aimed at determining the susceptibility profile to amoxicillin (10 mcg), ampicillin (10 mcg), ciprofloxacin (5 mcg), enrofloxacin (5 mcg), florfenicol (30 mcg), neomycin (30 mcg), sulfonamide (300 mcg), tetracycline (30 mcg) and trimethoprim-sulfamethoxazole (25 mcg) of typed serovars isolated. The samples were submitted to microbiological analyses by the conventional method. Salmonella sp. was isolated in 4.7% (12/256) of samples of one-day old chicks, in 6.2% (4/64) of the liver, 4.7% (3/64) of the hearts, 3.1% (2/64) of the yolk sacs, 4.7% (3/64) of meconium, and in10.2% (13/128) of the environment samples, being 9.4% (9/96) from drag swabs, 12.5% (4/32) from larvae and adult Alphitobius diaperinus and 4.4% (28/640) of the slaughterhouses samples, being 6.5% (21/320) of crops and 2.2% (7/320) of cecum samples. Salmonella enterica ser. Enteritidis was identified only in drag swabs and Alphitobius diaperinus. Salmonella enterica ser. Typhimurium was observed in the crops and cecum, which have shown high frequency of resistance to sulfonamides, 75% (6/8) and100% (3/30), respectively. Additionally, 20.7% (11/53) of the serovars have shown multiresistance to at least two of the tested drugs. In conclusion, Salmonella can be widely spread in broiler production flow, and the vertical pathway is still a major source of Salmonella insertion in the poultry production chain. The litter and bugs can perpetuate and disseminate Salmonella sp. as well as both the existence of strains resistant to antimicrobial and the occurrence of multiresistance are a threat to public health.(AU)

Enterobacterial detection and Escherichia coli antimicrobial resistance in parrots seized from the illegal wildlife trade.

Enteric bacteria are considered important potential pathogens in avian clinical medicine, causing either primary or opportunistic infections. The aim of this study was to evaluate the frequency of enterobacteria in the intestinal microbiota of psittacine birds and to determine the antimicrobial susceptibility of the Escherichia coli isolates cultured. Fecal samples were collected from 300 parrots captured from the illegal wildlife trade in Goiás, Brazil and were processed using conventional bacteriological procedures. A total of 508 isolates were obtained from 300 fecal samples: 172 E. coli (33.9% of isolates; 57.3% of individuals); 153 Enterobacter spp. (30.1% of isolates; 51.0% of individuals); 89 Klebsiella spp. (17.7% of isolates; 29.7% of individuals); 59 Citrobacter spp. (11.6% of isolates; 19.7% of individuals), 21 Proteus vulgaris (4.2% of isolates; 7.0% of individuals), 5 Providencia alcalifaciens (0.98% of isolates; 1.67% of individuals), 5 Serratia sp. (0.98% of isolates; 1.67% of individuals), 3 Hafnia aivei (0.59% of isolates; 1.00% of individuals), and 1 Salmonella sp. (0.20% of isolates; 0.33% of individuals). Escherichia coli isolates were subsequently tested for susceptibility to the following antibiotics: amoxicillin (70.93% of the isolates were resistant), ampicillin (75.58%), ciprofloxacin (23.25%), chloramphenicol (33.14%), doxycycline (64.53%), enrofloxacin (41.28%), tetracycline (69.19%), and sulfonamide (71.51%). Multi-resistance to three and four groups of antibiotics occurred in 40 samples (23.25%) and 4 samples (2.32%), respectively. These results demonstrate that illegally traded birds are carriers of potentially pathogenic bacteria, including E. coli strains with antimicrobial resistance.