ABSTRACT
We describe using major outer membrane protein (MOMP) typing as a screen to compare the Campylobacter jejuni porA gene sequences of clinical outbreak strains from human stool with the porA sequences of dairy farm strains isolated during two milk-borne campylobacteriosis outbreak investigations in California. The genetic relatedness of clinical and environmental strains with identical or closely related porA sequences was confirmed by multilocus sequence typing and pulsed-field gel electrophoresis analysis. The first outbreak involved 1,644 C. jejuni infections at 11 state correctional facilities and was associated with consumption of pasteurized milk supplied by an on-site dairy (dairy A) at a prison in the central valley. The second outbreak involved eight confirmed and three suspect C. jejuni cases linked to consumption of commercial raw milk and raw chocolate colostrum at another central valley dairy (dairy B). Both dairies bottled fluid milk on the farm and distributed the finished product to off-site locations. Altogether, C. jejuni was isolated from 7 of 15 (46.7%) bovine fecal, 12 of 20 (60%) flush alley water, and 1 of 20 (5%) lagoon samples collected on dairy A. At dairy B, C. jejuni was cultured from 9 of 26 (34.6%) bovine fecal samples. Environmental strains indistinguishable from the clinical outbreak strains were found in five flush alley water samples (dairy A) and four bovine fecal samples (dairy B). The findings demonstrate that MOMP typing is a useful tool to triage environmental isolates prior to conducting more labor-intensive molecular typing methods.
Subject(s)
Bacterial Proteins/genetics , Bacterial Typing Techniques/methods , Campylobacter Infections/microbiology , Campylobacter jejuni/classification , Campylobacter jejuni/genetics , Foodborne Diseases/microbiology , Porins/genetics , Animals , California/epidemiology , Campylobacter Infections/epidemiology , Campylobacter jejuni/isolation & purification , Cattle , DNA, Bacterial/chemistry , DNA, Bacterial/genetics , Disease Outbreaks , Electrophoresis, Gel, Pulsed-Field , Environmental Microbiology , Foodborne Diseases/epidemiology , Humans , Molecular Epidemiology/methods , Molecular Sequence Data , Multilocus Sequence TypingABSTRACT
A collection of 94 unusual members of the Enterobacteriaceae were screened for the presence of extended spectrum ß-lactamases (ESBLs) using the MicroScan ESßL plus dried confirmation panel. Presumptively positive strains were then confirmed for the presence of an ESBL by double disk diffusion, E-test strips (AB Biodisk, Solna, Sweden) and PCR for SHV, TEM, and CTX-M2 genes. Of the 18 strains initially positive on the ESßL panel only three strains (Leminorella grimontii, Klebsiella ozaenae, and Kluyvera ascorbata) were positive by confirmation methods. These results suggest laboratories should be cautious regarding the methodology employed in screening for the presence of ESBLs in enteric bacteria. However, it should be noted that of the 94 strains, 29 were found to be resistant to two or more of the antibiotics present in the MicroScan ESßL plus panel indicating that there are potential treatment issues with these organisms despite their lack of ESBLs.
