Phenotypic Detection Of Extended Spectrum Beta Lactamases Producing Organism Among Godfrey Okoye University Students

1.3.6 GES type

GES was initially described in a K. pneumoniae isolate from a neonatal patient just transferred to France from French Guiana. GES has hydrolytic activity against penicillin and extended-spectrum cephalosporin, but not against cephamycin or carbapenem, and is inhibited by β-lactamase inhibitors. These enzymatic properties resemble those of other class A ESBLs; thus, GES was recognized as a member of ESBLs (Danish et al 2015).

1.3.7 VEB-1, BES-1, and other ESBL type

Other unusual enzymes having ESBL have also been described (e.g. BES, CME, VE-B, PER, SFO, and GES). These novel enzymes are found infrequently (Danish et al 2015).

1.4 GLOBAL EPIDEMIOLOGY OF ESBL

Antimicrobial resistance has been declared a global threat to public health, as a massive increase in this problem has been observed in different parts of the world (Kang and Song 2013). The reported frequency of MDRs is increasing, putting strain on the public health organizations that are attempting to control this issue in many countries. The alarming increase in the prevalence of extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae has serious consequences for treatment outcomes (Pitout 2010). E. coli and Klebsiella species are important pathogens isolated from community-acquired and nosocomial-acquired infections, and have been studied extensively. The ESBL enzymes produced by these bacteria make them resistant to the first-choice antibiotic therapies that are commonly used. ESBL-positive strains are associated with a delay in the commencement of suitable antibiotic therapy, which consequently lengthens hospital stay and raises hospital costs. Failure of antibiotic therapy is responsible for higher mortality rates in patients infected with these bacteria. MDRs are posing a treatment challenge, and are emerging as a major cause of morbidity and mortality worldwide. Unfortunately, proper surveillance and documentation of such pathogens is very limited, especially in developing countries like Nigeria (Hayat et al, 2018).

The epidemiology of health-care associated infections has been characterized by the emergence of gram-negative multi drug resistant organisms, including ESBL-producing Enterobacteriaceae during the past decade. While nosocomial transmission was initially considered by their principal cause of spread, earlier report points to the importance of the food-chain as a continuous source of dissemination (Kluytmanset al 2013). In addition to a growing body of literature regarding the detection of ESBL- producing Enterobacteriaceae in retail meat and food worldwide, food has been reported as a vector for transmission of ESBL- producing Klebsiellapneumoniae in a hospital outbreak (Calboet al 2011). This leads to the conclusion that control teams should consider extending their surveillance towards food as it is a vector of ESBL.

1.4.1 AFRICA

In Africa, the prevalence of ESBL in Enterobacteriaceae has been researched at local levels in various countries, but there is no summarizing research on how prevalent ESBL is on the continent, what type of genes are involved, and where research is missing (Victor, 2014).

In patients treated in African hospitals, the prevalence of ESBL-producing Enterobacteriaceae has been shown to vary between countries and the type of specimen studied. There is a trend of higher prevalence of ESBL in stool samples than in other specimens. There is also a trend of increasing prevalence over time. This is noticeable in the Tunisian setting, where a large amount of studies are available. In two hospitals studied (study periods: 1999–2005 and 2010), ESBLs have increased from 11.7 to 77.8% among K. pneumoniae. (Aouniet al, 2010). In other settings, the trend is not noticeable among the few studies available. In the studied countries in Africa, the prevalence is widely different: in Algeria, it was between 16.4 and 31.4% in mainly urine samples (Barguiguaet al, 2012) and even 99% among Salmonella enterica in stool samples (Bentchoualaet al, 2011) 19 and 42.9%, respectively, in urine and stool samples in Egypt (Domanyet al, 2012); 32.6% among stool samples in Guinea-Bissau (Giskeet al, 2012); 11.7–77.8% in mainly urine, blood, and stool samples from Tunisia (Kechridet al, 2011); 62.8% in stool and blood samples from Ethiopia (Asratet al, 2011); 38.3% in urine samples from Rwanda (Bayinganaet al, 2011); 55.3 and 82.8% in stool samples from Cameroon (Assoumouet al, 2013); 10.3–27.5% in mainly urine and stool samples from Nigeria (Aibinuet al, 2012); and 8.8–13.1% in urine, nasopharyngeal, and wound samples from South Africa (Dubeet al, 2009).

1.4.1.1 Northern Africa

In Algerian hospitals, ESBLs existed in 16.4–31.4% of the samples. Class A ESBLs were most common, but plasmid-encoded AmpC (pAmpC) was also present (Canicaet al, 2011).

In Egypt, ESBLs were found in 11–42.9% of samples in both hospitals and communities; the genes involved were class A ESBLs (Eletrebyet al, 2009).

In Guinea-Bissau and Libya, class A and D ESBLs and a carbapenemase were found in 32.6 and 16%, respectively, in rectal or stool samples (Giskeet al, 2012).

In Morocco, class A and D ESBLs, pAmpC, and carbapenemases were found in hospital settings (Carattoliet al, 2012). In the community setting, class A and D ESBLs were found in between 1.3 and 7.5% of acquired urine samples (Amarouchet al, 2011).

In Tunisia, class A and D ESBLs, pAmpC, and carbapenemases were present, and the prevalence ranged from 11.7 to 77.8% in hospitals and was 0.7 and 7.3% in two communities (Kechridet al, 2011).

1.4.1.2 Eastern Africa

In Ethiopia and Kenya, 62.8 and 37.4%, respectively, of hospital and community samples were ESBLs (Asratet al, 2011). Class A ESBLs and pAmpC were present in the Kenyan sample (Butayeet al, 2012). In samples taken from Kenya and Malawi, class A and D ESBLs were found (Boyle et al, 2011). 

In Rwanda, ESBLs were found in 38.3% of hospital urine samples and in 5.9% of community urine samples (Bayinganaet al, 2011).

In Tanzania, class A ESBLs were found in various samples from hospital settings (Chakrabortyet al, 2011).

1.4.1.3 Central Africa

In Cameroon, class A and D ESBLs were found in 55.3 and 82.8% of hospital stool samples and in 17.2% of community stool samples (Assoumouet al, 2013).

In the Central African Republic, ESBLs were found in 11.3% of community urine samples (Bercionet al, 2009).