Author name:
خضر كريمش خضر الجوراني
Supervisor name:
سناء غالي جبر
Key words:
- Staphylococcus aureus
- Healthy humans
- Patients
- Plasmid virulence gene
Abstract:
Summary
Staph. aureus is a normal flora and opportunistic pathogen. It is the most
common in skin and soft tissue. This microbe can cause more diseases, for
example: burn inflammation and tonsillitis through the production of virulence
factors that are acquired by some plamidic virulence genes. The main research
objective explored the prevalence of (edin-c, sej and etb genes) in each patients
and healthy and its relationship with the development of infection in different
clinical sources.
This study was conducted in the Laboratory of Department of the
Pathological analysis, Faculty of Science, University of Thi-Qar from October
2019 - March 2020, A total of 640 samples were collected from patients and
healthy human. The research samples include 170 of patients suffered from burns
in the department of burns in Al-Hussein Teaching Hospital, also 150 samples of
patients were clinically diagnosed as having tonsillitis infections in the “E.N.T”
department in the AL Habboby Hospital while human healthy samples were 320
which collected from different parts of the body. These samples were cultured on
routine bacterial culture media which include: blood agar, MacConkey agar,
Mannitol Salt and DNAse, tested by Gram's stain, catalase test, coagulase test and
confirmed through API staph 20(BioMereux, France). Antibiotic susceptibility test
was performed by the modified Kirby-Bauer disc diffusion method according to
CLSI guidelines, while molecular diagnosis was depended on 16srRNA gene to
indicate Staph.aureus.
The data were statistically analyzed using the Chi-square test in SPSS
version 20; P-value ≤ 0.05 at 95%( The level of confidence) was considered for
statistical association.
According to the cultural, morphological, and biochemical characteristics,
Prevalence of Staph. aureus were 17.6% (n=30), 13.3% (n=20), and 5.94% (n=19)
II
to Burn patients, tonsillitis patients and healthy human. Production of some
virulence factors by Staph. aureus were been investigated. The results showed its
ability to produce hemolysin toxins, protease enzyme, and urease enzyme that
contributed to escape from the host immune response.
The study included testing all isolates against 12 antibiotics by the disc
diffusion method. The results revealed that Staph. aureus isolates were resistant to
Penicillin-G 100% in tonsillitis and healthy human isolates, but 90% in burn
isolates. Vancomycin resistance in tonsillar isolates was 15 % and 3.3 % in burn
isolates, but 0% in healthy humans. The outcomes of the study indicated that
resistance of Staph. aureus to Ciprofloxacin was 23.3% and 20% in burn,
tonsillitis patients, respectively, but 15.78 % in healthy humans. This study has
registered Sequential proportions related to Azithromycin. These were 50% for
burn patients and 60% for tonsillitis patients, but 42.10 % in healthy humans.
Clindamycin resistance in burn and tonsillitis were 73.3% and 75%, but in healthy
human were 5.26%, respectively. Nitrofurantoin 's resistance showed 13.3% to
burn and 10% to isolates of tonsillitis. Levofloxacin displayed the same resistance
levels(13.3% & 10%, respectively) to both clinical sites, but it was compared with
healthy humans, was zero %, and 10.52% to Levofloxacin, Nitrofurantoin,
respectively. The current study showed a noticeable rise in Erythromycin
resistance, which reached to 80% and 57% for both tonsillitis and burn isolates,
respectively, but 42.10% in healthy human. The antibiotic resistance values for
tonsillitis isolates of Ofloxacin and Gentamycin were the same at 15%, although
both antibiotics were recorded at 13 % and 10 % for burn isolates respectively,
whereas for healthy humans the levels of Ofloxacin and Gentamycin were 10.52
%.It was observed in study that the rate of antibiotic resistance to tetracycline 30%
and 23.3% for tonsillitis and burn isolates, respectively but in healthy humans was
36.84%. Close ranges of doxycycline resistance obtained at 20 % and 16.7 % for
tonsillitis and burn isolates, respectively, but were 21.05 % for healthy humans.
III
The results of phenotypic diagnostic were confirmed by polymerase chain
reaction (PCR) technique employing 16SrRNA gene that showed only 48\50
certain bacterial isolates of this microbe from patients while in healthy humans
were in line with phenotypic diagnostic (19\19), but results of molecular screening
of prevalence edin-c, sej and etb genes in burn patients had showed 48.27%,
62.06% and 62.06% respectively while in tonsillitis patients was 42.10%, 73.68%
and 47.36%. comparing to healthy humans, there were no results to determine
edin-c, sej except etb (21.05%).
