1. Introduction

P. aeruginosa is an important human opportunistic bacterium in the diabetic foot, it is a Gram-negative aerobic, rod-shaped non-fermenting bacterium with unipolar motility [1]. P. aeruginosa is often preliminarily identified by its pearlescent appearance and grape-like [2] or tortilla-like odour in vitro.

It can be responsible for a spectrum of presentations from superficial colonization of ulcers to extensive tissue damage, including osteomyelitis, septic arthritis and bacteraemia [3]. Definitive clinical identification of P. aeruginosa often includes identifying the production of pyocyanin and fluorescein, as well as its ability to grow at 42 ^°C [4,5]. P. aerugenosa is the most commonly isolated organism from diabetic ulcer [6]. In study from Malaysia culture of 86 diabetic septic foot patients revealed that P. aeruginosa (17.5%) [7] Dhanasekaran, et al. reported the prevalence of Pseudomonas species to be 18.79% from a diabetic centre in Chennai [8]. Fidelis Mbunda, et al. stated that P. aeruginosa (25.5%) was the most frequent gram negative bacteria isolated. P. aeruginosa is commonly resistant to antibiotics, and because of this it is a dangerous and dreaded pathogen. 44% of P. aerugenosa are multi drug resistant [6]. In the Mueller Hinton agar-based antibiogram resistogram pattern study of P. aeruginosa isolated from foot ulcers of diabetes patients, multidrug resistance for about 8 to 11 antibiotics was observed among 55.5% of the strains. No single antibiotic showed 100% sensitivity to all P. aeruginosa strains. Resistance was least with cefotaxime (16.6%), followed by an intermediate resistance of 66.7% observed for ciprofloxacin. Ciprofloxacin and cefotaxime were found to be better choices for diabetes patients with foot ulcers in this part of the region when compared to gentamicin, imipenem, piperacillin, and other third-generation cephalosporins [9].The objective of this study is to report on the frequency, antibiotic sensitivity, of Pseudomonas aeruginosa in Diabetic Foot Infection (DFI) in Gadarif Diabetics Center (GDC).

2. Patients and methods

This is a prospective observational analytic hospital based study in which all diabetic foot infections patients were questioned for personal in information, swabbed aseptically during a 2017- 2018. The study was conducted in Gadarif Diabetic Center (GDC). Three hundred and fifteen (wound swabs) were collected from diabetic foot infections patients, transferred immediately to the laboratory for bacteriological examination.

2.1. Technical methods

Wound swabs were inoculated on three plates of Nutrient agar, MacConkey's agar and blood agar were incubated aerobically at 37 ^°C for 24-48 hours, those which did not show visible growth, were discarded. All plates were examined with the naked eye for colonial morphology, the result of presumptive colony was recorded. Pure growth was used to identify the causative agents. and Gram’s stain was done to determine Gram reaction and bacterial morphology. All the isolated bacteria were examined by biochemical tests such as Catalase, MR, VP, indole, citrate, urease, oxidase, (OF) Oxidative/Fermentative test for further identification, the results were recorded.

2.2. Antimicrobial sensitivity

The bacterial isolates were subjected to a number of antibiotics by disc diffusion technique (Kirby-Bauer method). And the results were recorded according to National Committee for Clinical Laboratory Standards (NCCLSs), The same procedure was performed to the control organisms, American Type Culture Collection of P. aeruginosa (ATCC27853) was used as a standard control strain.

3. Results

A 315 swabs were obtained from Diabetic foot infections collected from Gadarif Diabetics Center (GDI) during 2017-2018. The swabs were cultured, purified by proper streaking on appropriate selective and differential culture media. The purified cultures of the isolates were then subjected to identification procedures which were based on the cultural characteristic, the microscopical examination and the biochemical characteristics. On the basis of the results of this identification test, it was found that (96; 30%) out of the total samples (315) were P. aeruginosa. (Figure 1).

The frequency distribution of Diabetic foot infections patients by P. aeruginosa isolation in relation to age and gender is shown in (Table 1). The most frequent isolation of the P. aeruginosa was noted in the age group above 40 years (81.25 %,) followed by those in the age group of 18 less 40 years (17.71%), less 18 years (1.04%). We found the relationship between Diabetic foot infections and sex. The prevalence rate was higher in male (69.8%) patients compared with females (30.2%).

Out of the 96 isolates of P. aeruginosa were found to be sensitive to Ciprofloxacin, Ceftazidime, Piperacillin, Gentamicin and Doycycline respectively (Figure 2).

Standard control was tested against P. aeruginosa and the size of the inhibition zones were recorded so as to be compared with the test organisms (Figure 3).

4. Discussion

The appearance of Diabetic Foot Infection (DFI) in Gadarif Diabetic Center is a matter of great concern since 96/315 (30%) patients had developed by P. aeruginosa in the period during 2017. Another studies of (DFI) showed that P. aeruginosa is isolated in less than 10% of wounds in studies primarily from developed northern countries [10]. In a previous study showed that P. aeruginosa (16%) [11]. Other authors reported from diabetic ulcers, p. aeruginosa in 17.5% [12]. Pappu K, et al. who reported that 76% of the organisms which were isolated from (DFI) were gram negative bacilli, Pseudomonas being the predominant pathogen (23%) [13]. When factors such as age and sex of the patient were considered, we found the occurrence of P. aeruginosa to be higher in males (67, 69.8%) and in patients in the age group 40 years and above (78, 81.3%). In contrast with other study reported the presence of P. aeruginosa was not associated with the patient's age [14]. Increasing resistance to different anti-pseudomonal drugs particularly among hospital strains, has been reported world-wide [15] and this is a serious therapeutic problem in the management of disease due to these organisms. In this study, antimicrobial susceptibility patterns of P. aeruginosa isolates were determined against different antimicrobial agents. The isolates were found to be sensitive to Ciprofloxacin (81. 84.4%) and followed by Ceftazidime (78. 81.3%), piperacillin (69.71.9%), Gentamicin (66.68.8%) and Doxycycline (12.12.5%). Chander and Raza conducted a similar study on the clinical isolates of P. aeruginosa in Kathmandu, Nepal, they found that the isolates were sensitive to Ciprofloxacin (70.48.3%), piperacillin (65.44.8%) [16]). Another survey and evaluation of the British Society for Antimicrobial Chemotherapy disc susceptibility test which conducted in UK about Antimicrobial susceptibility of Pseudomonas aeruginosa: by Caroline, et al. found that P. aeruginosa was sensitive to Ciprofloxacin (91.9%), piperacillin (96.1%), ceftazidime (97.7%), gentamicin (88.9%) [17].

5. Conclusion

The present study agrees with previous studies in that, P. aeruginosa was an important causative agents responsible for diabetic foot infection in Gadarif diabetic center. The most frequent isolation of the P. aeruginosa was noted in the age group above 40 years. The prevalence rate was higher in male patients compared with females. Results of the antimicrobial sensitivity of P. aeruginosa isolates against commonly used antibiotics demonstrated the occurrence of resistance to various antipseudomonal agents (Ciproflopxacin, Piperacillin, Ceftazidime and Gentamicin).

Figure 1: Percentage of P. aeruginosa in Diabetic foot infections.

Figure 2: Sensitive & resistant of P. aeruginosa clinical isolates against used antibiotics according to the NCCLSS zone diameter standards protocol.

Figure 3: Sensitive & resistant P. aeruginosa (ATCC 27853) standard control strain against used antibiotics according to the NCCLS zone diameter standards.

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Citation: Babiker RA, Elsharief UA, Mohammed NA (2019) Pseudomonas aeruginosa in Diabetic Foot Infections, Gadarif Diabetic Center, Sudan (2017-2018). J Trop Med Health 3: 140. DOI: 10.29011/JTMH-140.000040