Detection of CDT toxin genes in Campylobacter spp. strains isolated from broiler carcasses and vegetables in São Paulo, Brazil

Campylobacteriosis is a worldwide distributed zoonosis. One of the main virulence factors related to Campylobacter spp. in animals and humans is the cytolethal distending toxin (CDT), encoded by three adjacent genes (cdtA, cdtB, cdtC). The occurrence of Campylobacter spp. in samples of vegetables has not been reported in Brazil yet, and has seldom been described in the international literature. The detection of CDT in these strains has not been reported, either. The objectives of the present study were to determine the occurrence of Campylobacter spp. strains carrying virulence factors in samples of poultry and vegetables (lettuce and spinach) from different points of sale, thus verifying if vegetables are as an important vehicle for potentially virulent Campylobacter spp. strains as poultry. Twenty four strains were identified as Campylobacter jejuni by phenotypic and genotypic methods: 22 from broiler carcasses and two from lettuce samples. Three strains were identified as Campylobacter coli: two from broiler carcasses and one from lettuce. The presence of the cdt genes were detected in 20/24 (83.3%) C. jejuni strains, and 3/3 (100%) C. coli strains. The isolation of Campylobacter spp. strains with the cdt gene cluster in lettuce samples points to a new possible source of contamination, which could have an impact in the vegetable production chain and risk to public health. Results show that potentially virulent C. jejuni and C. coli strains remain viable in samples of broiler carcasses and vegetables at the points of sale.

Genotipificación y resistencia antibacteriana de cepas de Campylobacter spp aisladas en niños y en aves de corral / Genotyping and antibacterial resistance of Campylobacter spp strains isolated in children and in free range poultry

Poultry is a main reservoir and source of human infection in campylobacteriosis. Three hundred and forty one stool samples (291 human, 50 avian) were analyzed. In the human group, 220 samples were collected from children with acute diarrheal disease (183 inpatients, 37 outpatients) and 71 from healthy children. Erythromycin and ciprofloxacin agar dilution MIC tests, Penner serotyping and RAPD-PCR genotyping were performed on 23 strains isolated. C. jejuni was reported only in patients with acute diarrhea (5.4 percent inpatients, 2.2 percent outpatients). Campylobacter prevalence in poultry was 34 percent. Cross-resistance to nalidixic acid and ciprofloxacin was found in 33.3 percent of human samples and 11.8 percent of animal samples. Human samples could not be typed using the Penner method. F serotype was the most expressed in poultry. We obtained a total of 14 genotypes (4 / 5 human and 10/15 avian). In conclusion, the predominant species in poultry and humans was C. jejuni, a significant amount of quinolone-resistant human and avian samples were obtained, and avian genotypes and serotypes were not found in human samples. The latter would mean that another source of infection could exist; therefore other reservoirs must be studied.

Las aves de consumo constituyen uno de los principales reservorios y fuente de infección humana de la campilo-bacteriosis. Se analizaron 341 muestras de deposiciones, 291 humanas y 50 aviares. De las muestras, 220 de niños con síndrome diarreico agudo-SDA (183 hospitalizados y 37 consultantes ambulatorios) y 71 niños sanos. A las 23 cepas obtenidas se les realizó CIM por dilución en agar a eritromicina y ciprofloxacina, serotipificación de Penner y genotipiicación por RAPD-PCR. Se encontró Campylobacterjejuni sólo en pacientes con SDA, de ellos 5,4 por ciento ambulatorios y 2,2 por ciento hospitalizados. En aves, la prevalencia de Campylobacter spp., fue de 34 por ciento. Hubo resistencia cruzada a ácido nalidixico y ciprofloxacina en 33,3 por ciento cepas de origen humano y 11,8 por ciento animal. Las cepas humanas fueron no tipiicables por el método de Penner. Predominó entre las aves el serotipo F. Se obtuvo un total de 14 genotipos (4/5 humanos y 10/15 aviares). En conclusión, la especie predominante en aves de corral y en humanos fue C. jejuni, existiendo una alta prevalencia de cepas de origen humano y aviar resistentes a quinolonas. Los genotipos y serotipos aviares no fueron encontrados en cepas de origen humano, lo que indica que podría existir otra fuente de infección, por lo que se requiere estudiar otros reservorios.

Survey of chicken abattoir for the presence of Campylobacter jejuni and Campylobacter coli

The genus Campylobacter is of great importance to public health because it includes several species that may cause diarrhea. These species may be found in water, food and in the intestinal tract of chickens. This study investigated the presence of Campylobacter jejuni and Campylobacter coli in chicken abattoirs in São Paulo State, Brazil. A total of 288 samples of feces, feathers, scald water, evisceration water, chiller water, and the rinse water of eviscerated, not eviscerated and chilled carcasses were collected in six chicken abattoirs. Polymerase Chain Reaction (PCR) was performed in Campylobacter spp.-positive isolates using the gene HIP, specific for hippuricase enzyme from Campylobacter jejuni and aspartokinase gene, specific to detect Campylobacter coli. The percentage of positive isolates of Campylobacter jejuni was 4.9 percent (14/288). Isolation was greater in feces samples (22 percent, 8/36). One sample was positive for the species C. coli. In conclusion, the results indicate that it is necessary to improve quality control for Campylobacter spp. in chicken abattoirs.

O gênero Campylobacter tem grande destaque em saúde pública, principalmente por pertencerem a este gênero várias espécies que podem causar diarréia. Estas espécies podem ser encontradas em amostras de água, alimentos e no trato intestinal das aves. Este estudo investigou a presença de Campylobacter jejuni e Campylobacter coli em abatedouros de aves no Estado de São Paulo. As 288 amostras foram coletadas em seis estabelecimentos e incluíram: fezes; penas; água de escaldamento, de evisceração e de resfriamento; e água de enxaguadura de carcaça não eviscerada, eviscerada e resfriada. Após o isolamento microbiológico das amostras positivas de Campylobacter spp. foi realizada uma Reação em Cadeia da Polimerase (PCR) utilizando o gene HIP, da hipuricase, específico para Campylobacter jejuni e o gene da enzima aspartoquinase, específico para Campylobacter coli. A porcentagem de amostras positivas para Campylobacter spp. foi de 4,9 por cento (14/288), sendo que o isolamento foi maior em amostras de fezes (22 por cento, 8/36). Foi isolada uma amostra positiva para C. coli. Em conclusão, os resultados indicam que há uma necessidade de melhorar a qualidade higiênico-sanitária do controle de Campylobacter em abatedouros de aves.