Identification and Phylogenetic Profiling of Bacterial Populations in Perna perna L.

Abstract

The consumption of molluscan shellfish is associated with health benefits such as reducing the risk of heart diseases, lowering the amount of cholesterol in the blood and treatment of rheumatoid arthritis. Despite these benefits, there is a potential risk of bacterial infections attributed to the consumption of mussels. Sequences of DNA that encode to 16S rRNA were determined from Perna perna collected in Algoa Bay, Port Elizabeth, South Africa. The bacterial DNA was amplified by PCR with universal primer sets GM5F and 40 bp GC clamp 907R and visualized on agarose gel electrophoresis. Target amplicons 586 bp from each DNA were further purified and sequenced in ABI 3500 XL genetic analysers. Sequences of each of the bacterium were aligned while evolutionary history was inferred using the neighbour-joining method and a phylogenetic tree was constructed using MEGA 6 software. Twenty-eight bacterial strains were identified in the samples; while 89.30% of which belong to the Phylum Actinobacteria and were all Gram-positive, the remaining 10.70% belong to the Phylum Spirochaetes and were all Gram-negative. The bacterial isolates identified were predominantly members of the genera Saccharothrix with six species (21%) followed by Kocuria and Streptomyces with five species respectively (18%). Others include Spirochaeta (11%), Arthrobacter (7%), Rhodococcus (7%), Zhihengliuella (4%), Nesterenkonia (4%), Lechevalieria (4%), Citricoccus (3%) and Micrococcus (3%). This showed that Perna perna inhabiting Algoa Bay are reservoirs of various bacterial populations. This in turns emphasizes on proper cooking of Perna perna before consumption in order to safeguard the health of the consumers.

Keywords

• perna perna
• bacterial populations
• phylogeny
• sequencing
• 16s rrna gene.