Keywords : Virulence genes
Study Of Some Virulence Factors And Virulence Genes Produced By Gram (+Ve) And Gram (-Ve) Cocci Isolated From Clinical Samples In Al-Anbar Province/Iraq
European Journal of Molecular & Clinical Medicine,
2020, Volume 7, Issue 9, Pages 535-547
This study aimed to isolate the G (+ve) and G(-ve) cocci from different clinical samples and study some virulence factors and virulence genes produced by them .
In this study, (177) samples were collected from different clinical sources, including (49) blood samples, (43) urine samples, (30) pus swabs, (40) cervical swabs and (15) sputum samples from patients attending Ramadi Teaching Hospital for Maternity and Children, Ramadi Teaching Hospital in Ramadi in Al-Anbar province/Iraq during the period from 19/12/2018 to 12/5/2019, and (203) isolates were identified as Gram (+ve) and Gram (-ve) bacteria, then (166) Gram (+ve) and Gram (-ve) cocci were chosen as study samples.
After diagnosis of the isolates, results of Gram staining showed that the highest number and percentage of Gram positive and Gram negative bacteria were from urine samples 48(28.9%) followed by blood samples 44(26.5%) then pus swab and cervical isolates 37(22.3%) and 23(13.9%) respectively, while the lowest number and percentage of isolates were from sputum 14(8.4%). Staphylococcus aureus showed the highest number and percentage of isolates 48(28.9%). For gram (-ve) cocci, only (10.4%) of Neisseria gonorrhea was isolated from urine samples and (14.2%) of Moraxella catarrhalis was isolated from sputum samples
Regarding virulence factor production, the hemolysin producer isolates were the highest 103(62.04%), and results of hemolysin producing bacteria was S.aureus, S.hominis, S.haemolyticus, S.chromogenes, S.xylosu and S.warneri showed (100%) beta hemolysis, while only one isolate of the genus Micrococcus was beta-hemolytic all isolates of Streptococcus pyogenes and Streptococcus agalactiae showed (100%) beta hemolysis (β), whereas the isolates of Strept. pneumoniae, Aerococcus urinae and Aerococcus viridans showed (100%) partial or alpha (α) type hemolysis, and (8) isolates of E.faecalis showed complete hemolysis (β-haemolysis).
All S. aureus isolates were (100%) gelatinase producers Kocuria kristinae was (100%) producer, all Strep. pyogenes, Strep. Agalactiae, Strep. Anginosus, Strep. Lc. lactis lactis and Strep.mitis isolates showed (100%) ability to produce this enzyme, The (24) isolates of the genus Enterococcus bacteria were (100%) able to produce the enzyme gelatinize, including (19) E.faecalis isolates and (5) E. faecium. As for the genus Gram (-ve) cocci, two isolates of Moraxella catarrhalis showed (100%) ability to produce the gelatinase enzyme.
The number and percentage of urease enzyme producers were 49(29.51%), where 38(79.16%) of S.aureus isolates were able to produce it. Also, 3(17.64%) of S.hominis isolates were able to produce it, while only one isolate of S.lentus (20%) was able to produce it. Moreover, both S.xylosus and S.warneri isolates were (100%) urease-producers.
From the total (166) isolates, 20(12.04%) isolates formed biofilms. E.faecalis bacteria was the most biofilm-producing isolate 9(47.36%), followed by S.aureus bacteria 3(6.25%) then
S. lentus isolates (40%), while Kocuria rosea bacteria produced biofilm as 1(100%), Strep.pneumoniae and Strep.pyogenes produced as 1( 25%) for each isolate, and 1(50%) for Strep. anginosus isolate, whereas Strep.salivarius and Strep.mitis produced biofilm as 1(100%) isolate for each of them.
Also (100%) of the virulence genes icaC, srtC, and Emm were detected in S.aureus, E.faecalis and Strep.pyogenes isolates, which produced strong, moderate and weak biofilm types by using the PCR technology.