Trypsin-treated Ma-104: a sensitive cell line for isolating enteric viruses from environmental samples.

During a 1-year survey of enteroviruses in wastewater samples from the Lorraine area, three widely used continuous monkey kidney cell lines were tested: BGM, Vero, and trypsin-treated Ma-104. Decontaminated samples from secondary wastewater treatment plants (influent or effluent) were directly inoculated onto cells, and viruses were revealed after two passages with a liquid medium technique. Out of the total percentage of positive isolates with the three systems (32.7) 24.7% were found with Ma-104, 14.1% with BGM, and only 1.7% with Vero cells. Poliovirus was recovered more frequently with Ma-104 (12.3%) than with BGM (1.7%). Reovirus (3.5%) and echovirus (1.7%) were only found with Ma-104 cells; however, BGM cells allowed the isolation of a few group B coxsackieviruses (5.9%). It must be pointed out that 7.0% of samples with an unconfirmed cytopathic effect were found with BGM against 3.4% found with Ma-104, but they did not have significant differences. Because of its large spectrum of sensitivity, easy maintenance, and resistance to toxic effects, trypsin-treated Ma-104 may be recommended in conjunction with other cell lines for the detection of viruses from environmental samples, especially with the use of a liquid method.