Fluorescent-antibody method useful for detecting viable but nonculturable Salmonella spp. in chlorinated wastewater.
An indirect fluorescent-antibody (IFA) technique, which employed adsorbed Behring polyvalent I O antiserum, was used to detect Salmonella spp. in environmental water systems. The IFA method used in this study detected 95% of Salmonella serotypes encountered in human infections in France, with a sensitivity threshold of 7.5 x 10(3) bacteria per ml of wastewater. Specificity was assessed by testing IFA against Salmonella-free seawater and a variety of bacteria other than Salmonella spp. When used to examine raw and chlorinated wastewater over a 2-month period, the IFA method was successful in detecting Salmonella spp. in all 12 of the samples examined, with total numbers determined to be 4.5 x 10(5) to 3.3 x 10(7) salmonellae per 100 ml. In comparison, for the same samples, enumeration by culture, using the most-probable-number technique, was effective in detecting Salmonella spp. in only four of eight raw-water samples and one of four chlorinated water samples tested. Three samples were further tested by using the direct viable count procedure combined with IFA and results showed that 5 to 31.5% of the Salmonella spp. enumerated by this method in chlorinated water were substrate responsive.
Laboratoire de Microbiologie Pharmaceutique, Université de Rennes I, France.
C
C
Desmonts
J
J
Minet
R
R
Colwell
M
M
Cormier
D000165:Acridine Orange; D002470:Cell Survival; D002713:Chlorine / Q000494:pharmacology*; D005455:Fluorescent Antibody Technique; D006801:Humans; D012475:Salmonella / Q000276:immunology / Q000302:isolation & purification*; D012722:Sewage; D014871:Water Microbiology
D012722:Sewage; D002713:Chlorine; D000165:Acridine Orange