ABSTRACT
The detection of bacterial and parasitic gastrointestinal pathogens through culture and microscopy is laborious and time-consuming. We evaluated a molecular screening approach (MSA) for the detection of five major enteric pathogens: Salmonella enterica, Campylobacter jejuni, Giardia lamblia, Shiga toxin-producing Escherichia coli (STEC), and Shigella spp./enteroinvasive E. coli (EIEC), for use in the daily practice of a clinical microbiology laboratory. The MSA consists of prescreening of stool specimens with two real-time multiplex PCR (mPCR) assays, which give results within a single working day, followed by guided culture/microscopy of the positive or mPCR-inhibited samples. In the present 2-year overview, 28,185 stool specimens were included. The MSA was applied to 13,974 stool samples (49.6%), whereas 14,211 samples were tested by conventional methods only (50.4%). The MSA significantly increased the total detection rate compared to that of conventional methods (19.2% versus 6.4%). The detection of all included pathogens, with the exception of S. enterica, significantly improved. MSA detection frequencies were as follows: C. jejuni, 8.1%; G. lamblia, 4.7%; S. enterica, 3.0%; STEC, 1.9%; and Shigella spp./EIEC, 1.4%. The guided culture/microscopy was positive in 76.8%, 58.1%, 88.9%, 16.8%, and 18.1% of mPCR-positive specimens, respectively. Of all mPCRs, only 1.8% was inhibited. Other findings were that detection of mixed infections was increased (0.9% versus 0.02%) and threshold cycle (C(T)) values for MSA guided culture/microscopy-positive samples were significantly lower than those for guided culture/microscopy-negative samples. In conclusion, an MSA for detection of gastrointestinal pathogens resulted in markedly improved detection rates and a substantial decrease in time to reporting of (preliminary) results.
Subject(s)
Bacteriological Techniques/methods , Enterobacteriaceae/isolation & purification , Gastrointestinal Diseases/diagnosis , Giardia lamblia/isolation & purification , Mass Screening/methods , Molecular Diagnostic Techniques/methods , Parasitology/methods , Adolescent , Adult , Aged , Aged, 80 and over , Child , Child, Preschool , Enterobacteriaceae/genetics , Feces/microbiology , Feces/parasitology , Female , Gastrointestinal Diseases/microbiology , Gastrointestinal Diseases/parasitology , Giardia lamblia/genetics , Humans , Infant , Infant, Newborn , Male , Middle Aged , Time Factors , Young AdultABSTRACT
A steady increase in the incidence of Guillain-Barré syndrome (GBS) with a seasonal preponderance, almost exclusively related to Campylobacter jejuni, and a rise in the incidence of laboratory-confirmed Campylobacter enteritis have been reported from Curaçao, Netherlands Antilles. We therefore investigated possible risk factors associated with diarrhea due to epidemic C. jejuni. Typing by pulsed-field gel electrophoresis identified four epidemic clones which accounted for almost 60% of the infections. One hundred six cases were included in a case-control study. Infections with epidemic clones were more frequently observed in specific districts in Willemstad, the capital of Curaçao. One of these clones caused infections during the rainy season only and was associated with the presence of a deep well around the house. Two out of three GBS-related C. jejuni isolates belonged to an epidemic clone. The observations presented point toward water as a possible source of Campylobacter infections.
