Prevalence of metallo-β-lactamase acquired genes among carbapenems susceptible and resistant Gram-negative clinical isolates using multiplex PCR, Khartoum hospitals, Khartoum Sudan

Abstract

Background

The increased prevalence of carbapenem-resistant Gram-negative isolates caused by Metallo-β-lactamase (MBL) is worrisome in clinical settings worldwide. The mortality rate associated with infections caused by MBLs producing organisms ranging from 18 to 67%.

This study aimed to determine the prevalence of Metallo-β-lactamase genes among some Gram-negative clinical isolates (Carbapenems susceptible and resistant).

Methods

This paper describes a descriptive cross-sectional study carried out to detect MBL genes such as ( blaVIM, blaIMP and blaNDM) by multiplex PCR mixture reaction among 200 Gram-negative clinical isolates ( Citrobacter spp, Escherichia coli, Enterobacter spp, Klebsiella pneumoniae, Pseudomonas aeruginosa, Proteus mirabilis, Proteus valgaris ). Khartoum hospitals during 2015 to 2016.

Limitation: The study organisms were not evaluated for non-MBL carbapenemases, such as KPC and OXA-48.

Results

The prevalence of MBL genes by multiplex PCR assays among 200 Gram-negative clinical isolates was 72(36.1%). MBL positive genes among 100 carbapenems sensitive and 100 resistant isolates were 27(27%) and 45(45%) respectively. There was a statistically, significant association between the antimicrobial susceptibility and the presences of MBL genes ( P.value = 0.008).

E.coli was the predominant species possessing MBL genes 26(36.1%), with 22(30.7%) species having a combination of MBL genes.

Verona integron Metallo beta-lactamase ( VIM) was the most frequent genes 28(38.9%) out of 72 MBL detected genes, followed by imipenemase ( IMP) was 19(26.4%), and consequently, New Delhi Metallo beta lactamase was 3(4.2%).

Conclusion

This study revealed a high prevalence of MBL genes in some Gram-negative isolates from Khartoum State Hospitals which were not previously established in these hospitals.

Electronic supplementary material

The online version of this article (10.1186/s12879-018-3581-z) contains supplementary material, which is available to authorized users.