Molecular characterization of Pseudomonas aeruginosa isolates from various clinical specimens in Khartoum/Sudan: Antimicrobial resistance and virulence genes

Abstract

Background: Pseudomonas aeruginosa is a pathogenic organism responsible for frequent wound and nosocomial infections worldwide. Its infections are difficult to control since the organism is known to rapidly develop antibiotic resistance and becomes multidrug-resistant (MDR) during treatment of patients.
 Aim of the study: This study was intended to investigate the occurrence of certain important types of (ESBL) and (MBL) enzymes in association with important specific virulence factors associated with P. aeruginosa clinical isolates from Khartoum, Sudan.
 Methods: This study investigated 70 P. aeruginosa isolates which were collected from patients admitted to four major hospitals in Khartoum (Fedail, Ribat, Ibn Sina and Soba hospitals). These isolates were recovered from 40 wound swabs (57.1%), 27 urine samples (38.6%), and 3 pleural fluid samples (4.3%) of patients. Higher numbers of isolates were recovered from males 42 (60%) than in females 28 (40%). All P. aeruginosa isolates were first confirmed by conventional biochemical and second using molecular PCR tests. PCR methods were also used for detecting the presence of the virulence genes ToxA, AlgD, LasB, exoS, exoU, CTX, GES-1, and genes of VIM, IMP, KPC, CTX, VEB-1 and SHV-1.
 Results: Antimicrobial susceptibility testing of P. aeruginosa isolates showed a high resistance to azetronam 49 (70%), followed by ceftazidime 32 (45.7%), 16 ciprofloxacin (22.9%), gentamicin 13 (18.6 %), piperacillin-tazobactam 11 (15.7%), amikacin 9 (12.9 %), and imipenem 6 (8.6%) showed the least resistance. All isolates were positive for algD and lasB (100%), followed by toxA (90%), exoS (34.3), exoU (24.3%), respectively. The rates of detected ESBL genes blaTEM, blaCTX-m, blaSHV-1,GES-1, were 3.3%, 6.6%, 10%, 3.3%,10%, respectively, but all isolates were negative for bla-KPC and bla- VIM and IMP . The percentages of pigment production were 61.4% for pyocyanin, 37.1% for pyoverdin and 1.4% for pyorubin.
 Conclusion: The study demonstrated high rates of antimicrobial resistance markers to most commonly used antibiotics in treatment of P. aeruginosa infections. The majority of the isolates from urine and wound samples carried at least three potential virulence factor genes of algD, lasB and toxA and without any significant relation to their antimicrobial resistance markers.

Prevalence of multi-drug resistant Pseudomonas aeruginosa isolated from selected residential sewages in Dutsin-Ma, Katsina State, Nigeria

“…Our findings reveal gentamicin to be the most effective antibiotic, with varying degrees of susceptibility to this antibiotic observed from Miami (50%) and Kadangaru (40%) isolates. This observation is in agreement with the high susceptibility (84% and 81.6%) to gentamicin reported by earlier studies conducted in Pakistan 26 and Sudan 5 respectively. This phenomenon may be predicated on the reduced administration of gentamicin in those regions.…”

“…These bacteria have been largely implicated in nosocomial infections. 5 Nosocomial infections associated with P. aeruginosa include but not limited to bacteremia, burn infection, cystic fibrosis, pneumonia and urinary tract infection. 6 Sadly, bacteremia caused by this bacterium is often associated with high mortality when compared with other Gram-negative bacteria.…”

Characterization of selected multidrug-resistant bacteria from clinical and hospital environmental sources using Vitek 2 compact system

“…On the contrary, colistin sulphate and kanamycin resistance was the least observed in both clinical and environmental isolates respectively. This agrees with other studies who studied aminoglycosides resistance in clinical and environmental isolates 33,34 . Vitek 2 compact system as an e cient diagnostic tool gave the explicit identities of isolates and con rmed the antibiogram pro les of previously screened MDR isolates and revealed other resistance phenotypes, several other pathogens that could not be tentatively identi ed with conventional biochemical tests were also detected.…”

Antimicrobial resistance and carbapenemase dissemination in Pseudomonas aeruginosa isolates from Libyan hospitals: a call for surveillance and intervention

“…Due to the limited studies on clinical pseudomonas isolates in Libya, we can’t assert that the dissemination of bla TEM , bla SHV-1 or bla CTXM is lower in them compared to Enterobacteriaceae . However, a study in Sudan, a neighboring country, had shown low distribution rates of ESBL genes among P. aeruginosa clinical isolates [ 32 ]. In their study, the distribution rate of selected ESBL genes among 70 P. aeruginosa isolates was 6.6% for bla CTXM , 10% for bla SHV-1 and 3.3% for bla TEM , which are in line with our findings.…”