Survival and transport of bacteria in egg washwater.

An evaluation of methods for monitoring the quality of water used to wash eggs at grading stations was undertaken to improve maintenance of bacterial viability during overnight sample transport. Bacterial content of samples at analysis would then better reflect conditions at the time eggs were washed. The interactive effects of temperature and the highly alkaline water conditions upon viability were the subjects of this study. Nine transport methods were examined for their efficacy in recovering total and coliform bacteria from recycled water used to wash eggs, and these were compared with samples analyzed at two commercial egg grading stations. Samples were shipped under test to the laboratory for analysis the following day. The survival of Staphylococcus aureus and Escherichia coli was also examined, but in a synthetic washwater matrix under various combinations of temperature (6 to 32 degrees C) and pH (9.5 to 10.5) to determine whether there was likely to be a different response to variations in transport treatment among gram-positive and -negative bacteria. S. aureus was much more resistant to the lethal effects of high pH and moderate temperature than E. coli. These results indicated that samples of high pH should be held (transported) at less than or equal to 13 degrees C to optimize bacterial survival. Considering cost, ease of manipulation, and the ability to protect both coliforms and the bacterial population as a whole, the method of choice for transport of industrial samples was the direct addition of washwater to containers in which powdered KH2PO4 and Na2S2O3 had been placed to yield final concentrations, when dissolved, of 0.2 and 0.05% (wt/vol), respectively.

Production and characterization of monoclonal antibodies against serotype strains of Pseudomonas aeruginosa.

Monoclonal antibodies against 12 of the 17 IATS serotype strains of Pseudomonas aeruginosa were produced. Eighty-seven hybridoma clones were isolated, and the antibodies secreted were found to be reactive with both Formalin-fixed whole cells and purified lipopolysaccharide of homologous strains in enzyme-linked immunosorbent assays. Among these monoclonal antibodies, the predominant antibody class was immunoglobulin M (IgM) (76%), although antibodies of the IgG2a and IgG3 isotypes were also produced. The monoclonal antibodies could further be divided into two groups based on their ability to agglutinate whole cells of homologous strains. The agglutinating monoclonal antibodies were found to immunoblot with the O side chains of homologous lipopolysaccharide, while the nonagglutinating monoclonal antibodies were found to be reactive with outer membrane protein-associated lipopolysaccharide. The applicability of monoclonal antibodies for serotyping was examined, and several antibodies were found to agglutinate whole cells and immunoblot with the O antigen of corresponding serotypes of clinical isolates from cystic fibrosis patients. In conclusion, a set of monoclonal antibodies against the IATS serotype strains of P. aeruginosa have been produced. These antibodies represent a bank of invaluable immunological reagents which may have application in serotyping, epitope mapping, lipopolysaccharide structural determination, and studies of protection against P. aeruginosa.