Acinetobacter baumannii detected on modified charcoal-cefoperazone-deoxycholate agar in a waste stabilization pond.

Campylobacter is a recommended reference pathogen for the verification and validation of water recycling schemes in Australia and globally. In a larger study investigating the efficacy of pathogen removal in waste stabilization ponds (WSP), we cultivated bacteria from wastewater samples on modified charcoal-cefoperazone-deoxycholate agar (mCCDA) targeting the growth of Campylobacter. A high number of colonies characteristic of Campylobacter grew on this selective medium, but this did not correlate with qPCR data. Using primers targeting the 16S rRNA gene, and additional confirmatory tests to detect VS1, ompA, blaOXA-51-like, blaOXA-23-like genes, we tested 80 random colonies from 10 WSP samples. All 80 were identified as Acinetobacter baumannii. Wastewater grab samples taken three times over 6 months throughout the WSP system showed removal of A. baumannii in the WSP at rates similar to that of Escherichia coli. Our study suggests that mCCDA agar is not a suitable medium for isolating Campylobacter from environmental samples and that A. baumannii can be used as an indicator for removal of pathogens in WSPs.

Campylobacter in broiler slaughter samples assessed by direct count on mCCDA and Campy-Cefex agar

ABSTRACT Campylobacter spp. cause foodborne illnesses in humans primarily through the consumption of contaminated chicken. The aim of this study was to evaluate the United States Department of Agriculture's (USDA) recommended methodology, protocol MLG 41.02, for the isolation, identification and direct plate counting of Campylobacter jejuni and C. coli samples from the broiler slaughtering process. A plating method using both mCCDA and Campy-Cefex agars is recommended to recover Campylobacter cells. It is also possible to use this method in different matrices (cloacal swabs and water samples). Cloacal swabs, samples from pre-chiller and post-chiller carcasses and samples of pre-chiller, chiller and direct supply water were collected each week for four weeks from the same flock at a slaughterhouse located in an abattoir in southern Brazil. Samples were analyzed to directly count Campylobacter spp., and the results showed a high frequency of Campylobacter spp. on Campy-Cefex agar. For the isolated species, 72% were identified as Campylobacter jejuni and 38% as Campylobacter coli. It was possible to count Campylobacter jejuni and Campylobacter coli from different samples, including the water supply samples, using the two-agar method. These results suggest that slaughterhouses can use direct counting methods with both agars and different matrices as a monitoring tool to assess the presence of Campylobacter bacteria in their products.

Campylobacter in broiler slaughter samples assessed by direct count on mCCDA and Campy-Cefex agar.

Campylobacter spp. cause foodborne illnesses in humans primarily through the consumption of contaminated chicken. The aim of this study was to evaluate the United States Department of Agriculture's (USDA) recommended methodology, protocol MLG 41.02, for the isolation, identification and direct plate counting of Campylobacter jejuni and C. coli samples from the broiler slaughtering process. A plating method using both mCCDA and Campy-Cefex agars is recommended to recover Campylobacter cells. It is also possible to use this method in different matrices (cloacal swabs and water samples). Cloacal swabs, samples from pre-chiller and post-chiller carcasses and samples of pre-chiller, chiller and direct supply water were collected each week for four weeks from the same flock at a slaughterhouse located in an abattoir in southern Brazil. Samples were analyzed to directly count Campylobacter spp., and the results showed a high frequency of Campylobacter spp. on Campy-Cefex agar. For the isolated species, 72% were identified as Campylobacter jejuni and 38% as Campylobacter coli. It was possible to count Campylobacter jejuni and Campylobacter coli from different samples, including the water supply samples, using the two-agar method. These results suggest that slaughterhouses can use direct counting methods with both agars and different matrices as a monitoring tool to assess the presence of Campylobacter bacteria in their products.

Polycarbonate filtration technique is noninferior to mCCDA for isolation of Campylobacter species from stool samples.

A total of 5963 diarrheic stool samples were cultivated for Campylobacter spp. with use of modified charcoal cefoperazone deoxycholate agar (mCCDA) plates as well as a polycarbonate (PC) filter technique on blood agar plates. A total of 376 Campylobacter jejuni/coli were isolated from both PC and mCCDA. Six and three were isolated from PC and mCCDA only, respectively (P = ns). The PC technique is noninferior to mCCDA for isolation of C. jejuni/coli.

Evaluation of potassium-clavulanate-supplemented modified charcoal-cefoperazone-deoxycholate agar for enumeration of Campylobacter in chicken carcass rinse.

Potassium-clavulanate-supplemented modified charcoal-cefoperazone-deoxycholate agar (C-mCCDA) that was described in our previous study was compared with original mCCDA for the enumeration of Campylobacter in pure culture and chicken carcass rinse. The quantitative detection of viable Campylobacter cells from a pure culture, plated on C-mCCDA, is statistically similar (P > 0.05) to mCCDA. In total, 120 chickens were rinsed using 400 mL buffered peptone water. The rinses were inoculated onto C-mCCDA and mCCDA followed by incubation at 42 °C for 48 h. There was no statistical difference between C-mCCDA (45 of 120 plates; mean count, 145.5 CFU/mL) and normal mCCDA (46 of 120 plates; mean count, 160.8 CFU/mL) in the isolation rate and recovery of Campylobacter (P > 0.05) from chicken carcass rinse. The Pearson correlation coefficient value for the number of Campylobacter cells recovered in the 2 media was 0.942. However, the selectivity was much better on C-mCCDA than on mCCDA plates (P < 0.05). Significantly fewer C-mCCDA plates (33 out of 120 plates; mean count, 1.9 CFU/mL) were contaminated with non-Campylobacter cells than the normal mCCDA plates (67 out of 120 plates; mean count, 27.1 CFU/mL). The C-mCCDA may provide improved results for enumeration of Campylobacter in chicken meat alternative to mCCDA with its increased selectivity the modified agar possess.

Utilização de caldo Bolton no enriquecimento seletivo em comparação ao plaqueamento direto na pesquisa de Campylobacter spp. em carcaças resfriadas de frango / Use of Bolton broth for selective enrichment and comparative analysis of its performance with direct plating methodology for isolating

O objetivo deste estudo foi comparar o enriquecimento seletivo e o plaqueamento direto no isolamento das espécies termofílicas de Campylobacter spp. em 30 amostras de carcaças de frango resfriadas adquiridas em supermercados, feiras livres e abatedouros no município do Rio de Janeiro, no período de julho de 2009 a julho de 2010. Foi realizada a enxaguadura da carcaça com água peptonada tamponada a 1% para recuperação das bactérias. Para o plaqueamento direto, foram utilizados ágar carvão cefoperazone de soxicolato modificado e ágar campy-cefex. Para o enriquecimento seletivo, foi empregado o caldo Bolton em concentrações simples e dupla. Foi detectada a presença de Campylobacter spp. em 21 amostras(70%), sendo 6 (28,6%) de abatedouros (3 com Serviço de Inspeção Estadual e 3 sem inspeção), 8 (38,1%) de supermercados e 7 (33,3%) de feiras livres. Não houve diferença estatisticamente significativa entre os resultados obtidos nesses estabelecimentos. As 21 amostras positivas foram isoladas do plaqueamento direto, 2 (9,5%) foram isoladas também no caldo Bolton simples e nenhuma no caldo Bolton duplo. O plaqueamento direto foi considerado o método mais rápido e eficiente, e apresenta menor custo que o enriquecimento seletivo na recuperação de Campylobacter spp. em carcaças resfriadas de frango.