Impact of changing from staining to culture techniques on detection rates of Campylobacter spp. in routine stool samples in Chile

Abstract

BackgroundCampylobacter is a leading cause of bacterial gastroenteritis, but sensitive diagnostic methods such as culture are expensive and often not available in resource limited settings. Therefore, direct staining techniques have been developed as a practical and economical alternative. We analyzed the impact of replacing Campylobacter staining with culture for routine stool examinations in a private hospital in Chile.MethodsFrom January to April 2014, a total of 750 consecutive stool samples were examined in parallel by Hucker stain and Campylobacter culture. Isolation rates of Campylobacter were determined and the performance of staining was evaluated against culture as the gold standard. Besides, isolation rates of Campylobacter and other enteric pathogens were compared to those of past years.ResultsCampylobacter was isolated by culture in 46 of 750 (6.1 %) stool samples. Direct staining only identified three samples as Campylobacter positive and reached sensitivity and specificity values of 6.5 and 100 %, respectively. In comparison to staining-based detection rates of previous years, we observed a significant increase of Campylobacter cases in our patients.ConclusionDirect staining technique for Campylobacter had a very low sensitivity compared to culture. Staining methods might lead to a high rate of false negative results and an underestimation of the importance of campylobacteriosis. With the inclusion of Campylobacter culture, this pathogen became a leading cause of intestinal infection in our patient population.

Diagnóstico microbiológico y vigilancia epidemiológica de la campilobacteriosis en Chile: Situación actual y desafíos futuros

“…A pesar del escaso diagnóstico microbiológico en el medio nacional, en el período 2015-2016 se notificaron tres brotes de enfermedades trasmitidas por alimentos (ETA) atribuibles a Campylobacter spp. 14 .…”

“…De hecho, en el caso de alimentos, este patógeno no se encuentra incluido en el Reglamento Sanitario de los Alimentos (RSA) del Ministerio de Salud de Chile 21 y los datos de la presencia de especies de Campylobacter spp. en plantas de procesamiento chilenas son limitados 14 . Sin embargo, algunos estudios desarrollados en el centro y sur de Chile han demostrado que C. jejuni y C. coli presentan una alta prevalencia en muestras fecales de animales de granja y en la carne derivada de éstos 22,23 .…”

Genomic analysis of the diversity, antimicrobial resistance and virulence potential of clinical Campylobacter jejuni and Campylobacter coli strains from Chile

“…Nevertheless, recent reports suggest that the burden of campylobacteriosis in Chile has been greatly underestimated due to suboptimal diagnostic protocols in both public and private health centers [15]. A recent study showed a 10-fold increase of the detection rate of Campylobacter in human stool samples after changing from microscopic stool examination by Gram staining (the routine protocol in Chilean health centers) to culturedependent techniques [16]. In another study from the same group, Campylobacter spp.…”

Occurrence and antimicrobial susceptibility of thermophilic Campylobacter species isolated from healthy children attending municipal care centers in Southern Ecuador

“…The available clinical, laboratory and epidemiological data have been produced mainly in developed countries, where national surveillance programs for campylobacteriosis exist 8 . In general, developing countries do not have this kind of programs or they are just implementing them, which does not allow reliable and conclusive epidemiological data 9 . On the other hand, in developing countries, Campylobacter is not routinely diagnosed as enteric pathogens, thus, their frequency in infant community-acquired diarrhea is commonly underestimated 10 .…”