Summary auto-generated
This study presents a new protein profile typing method for Morganella morganii, a gram-negative bacterium associated with nosocomial infections and gastrointestinal disease. Researchers analyzed 150 M. morganii strains, predominantly from fecal samples, using sodium dodecyl sulfate-polyacrylamide gel electrophoresis to examine outer membrane proteins. The strains exhibited diverse characteristics including haemolytic and non-haemolytic phenotypes, multiple O serogroups, bacteriocin types, and biotypes. Analysis of outer membrane proteins in the 35-40 kilodalton range identified 21 distinct protein profile types (designated A-U). The typing method proved stable across different culture media and remained consistent over repeated testing. Importantly, protein profile types were independent of both O antigen and bacteriocin type, making this technique complementary to existing typing schemes. While less discriminating than O serotyping or bacteriocin typing alone, protein profiling provided superior discrimination compared to biotyping or phage typing. The method successfully differentiated strains that were indistinguishable by traditional O serotyping, suggesting it offers practical value as a simpler, routine typing method for clinical laboratories lacking resources for more complex typing schemes.
Key findings
- Protein profile typing of outer membrane proteins (35-40 kDa) differentiated 150 M. morganii strains into 21 distinct types, with types A and E being most common (42.6% and 11.3% respectively)
- The OMP typing method is independent of O antigen and bacteriocin type, yet can discriminate between strains identical by these traditional methods, providing complementary strain differentiation
- Protein profiles were stable across different culture media and remained unchanged over repeated examination over one year, making the method reliable for routine use
- Combined application of protein profiling, O serotyping, and bacteriocin typing provides the finest strain recognition, with each method contributing independent discriminatory power
This summary was generated automatically from the article PDF and is not part of the original publication. Refer to the PDF for the authoritative text.
Abstract
A new, simple and stable method for typing Morganella morganii strains is described. The 150 strains examined, principally from faeces, contained haemolytic and non-haemolytic representatives of diverse O serogroup, bacteriocin type and biotype. Among the biotypes were some trehalose-fermenting, tetracycline-resistant strains and some non-motile, tetracycline-sensitive, glycerol fermenters. After analysis of cell lysates by sodium dodecyl sulphate-discontinuous polyacrylamide gel electrophoresis, strains could be differentiated into 21 types on the basis of outer membrane proteins (OMP) of 35-40 Kda. The OMP profile was not altered by culture on various common media and was unrelated to either O antigen or morganocin p-type. The finest strain recognition in M. morganii can be achieved by application of all three distinct typing methods.