Isolation and Identification of Shimwellia blattae from the Gut of the Hospital Cockroach Blatta orientalis in Annaba City, Algeria

The overall aim of this paper was to divulge the pathogenic and beneficial bacterial flora of cockroaches (Blatta orientalis) living in a hospital area in Annaba city, Algeria. Thirteen cockroaches were randomly apprehended in sterile conditions during March 2022 in two different hospitals in Annaba, “El Bouni” Hospital and the “Sainte-Therese” Hospital. Bacterial strains were isolated from the imprint of the insect on Petri dishes previously inoculated with different media, also from external and internal body part suspensions of the captured specimens. Biochemical identification was established using the analytical profile Index (API) System (Biomerieux, France). The identification of the enteric-screened strain was confirmed using molecular sequencing of the 16S rRNA gene and phylogenetic analysis was performed. The results showed a high prevalence of the pathogenic strains isolated from the oriental cockroach Blatta orientalis (225 strains), such as Serratia liquefaciens, Raoultella ornithinolytica, Pseudomonas luteola, Enterobacter aerogenes, Hafniaalvei and Bacillus sp. Phylogenetic analysis of the enteric bacteria confirmed the affiliation with Shimwellia blattae NCTC10965 (100%), Basonym Escherichia blattae, which is a natural cyanocobalamin producer. Results confirm at the same time the symbiotic relationship between S. blattae and Blatta orientalis, but also point out the underrepresented potential of these insects as a source of strains with biotechnological interest.