Bacterial profile and antimicrobial resistance patterns of infected diabetic foot ulcers in sub-Saharan Africa: a systematic review and meta-analysis

Diabetes-related lower limb wounds: Antibiotic susceptibility pattern and biofilm formation

The expeditious incidence of diabetes mellitus in Riyadh, Saudi Arabia, there is a significant increase in the total number of people with diabetic foot ulcers. For diabetic lower limb wound infections (DLWs) to be effectively treated, information on the prevalence of bacteria that cause in this region as well as their patterns of antibiotic resistance is significant. Growing evidence indicates that biofilm formers are present in chronic DFU and that these biofilm formers promote the emergence of multi-drug antibiotic resistant (MDR) strains and therapeutic rejection. The current study targeted to isolate bacteria from wounds caused by diabetes specifically at hospitals in Riyadh and assess the bacterium's resistance to antibiotics and propensity to develop biofilms. Totally 63 pathogenic microbes were identified from 70 patients suffering from DFU. Sixteen (25.4%) of the 63 bacterial strains were gram-positive, and 47 (74.6%) were gram-negative. Most of the gram-negative bacteria were resistant to tigecycline, nitrofurantoin, ampicillin, amoxicillin, cefalotin, and cefoxitin. Several gram-negative bacteria are susceptible to piperacillin, meropenem, amikacin, gentamicin, imipenem, ciprofloxacin, and trimethoprim. The most significant antibiotic that demonstrated 100% susceptibility to all pathogens was meropenem. Serratia marcescens and Staphylococcus aureus were shown to have significant biofilm formers. MDR bacterial strains comprised about 87.5% of the biofilm former strains. To the best of our knowledge, Riyadh, Saudi Arabia is the first region where Serratia marcescens was the most common bacteria from DFU infections. Our research findings would deliver information on evidence-based alternative strategies to develop effective treatment approaches for DFU treatment.

In vitro inhibition of biofilm and virulence factor production in azole-resistant strains of Candida albicans isolated from diabetic foot by Artemisia vulgaris stabilized tin (IV) oxide nanoparticles

The advent of nanotechnology has been instrumental in the development of new drugs with novel targets. Recently, metallic nanoparticles have emerged as potential candidates to combat the threat of drug-resistant infections. Diabetic foot ulcers (DFUs) are one of the dreadful complications of diabetes mellitus due to the colonization of numerous drug-resistant pathogenic microbes leading to biofilm formation. Biofilms are difficult to treat due to limited penetration and non-specificity of drugs. Therefore, in the current investigation, SnO2 nanoparticles were biosynthesized using Artemisia vulgaris (AvTO-NPs) as a stabilizing agent and were characterized using ultraviolet-visible (UV-vis) spectroscopy, Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDX). Furthermore, the efficacy of AvTO-NPs against biofilms and virulence factors of drug-resistant Candida albicans strains isolated from DFUs was assessed. AvTO-NPs displayed minimum inhibitory concentrations (MICs) ranging from 1 mg/mL to 2 mg/mL against four strains of C. albicans. AvTO-NPs significantly inhibited biofilm formation by 54.8%-87%, germ tube formation by 72%-90%, cell surface hydrophobicity by 68.2%-82.8%, and exopolysaccharide (EPS) production by 69%-86.3% in the test strains at respective 1/2xMIC. Biosynthesized NPs were effective in disrupting established mature biofilms of test strains significantly. Elevated levels of reactive oxygen species (ROS) generation in the AvTO-NPs-treated C. albicans could be the possible cause of cell death leading to biofilm inhibition. The useful insights of the present study could be exploited in the current line of treatment to mitigate the threat of biofilm-related persistent DFUs and expedite wound healing.

A Systematic Review of the Microbial Landscape of Diabetic Foot Ulcers in Uganda

Background

Diabetes is a growing health concern globally. Poorly managed diabetes may result in diabetic foot ulcers (DFU), which can become a source of chronic infection known as diabetic foot infections. The increasing trend of diabetes in Uganda speaks to the potential for diabetic foot ulcers which may eventually become infected and their attendant impact on the quality of life of diabetic patients. This review assesses the microbial diversity of DFUs in Uganda, aiming to guide treatment and identify research gaps.

Main Body of the Abstract

We searched PubMed, Scopus and Embase for studies conducted in Uganda that reported isolating microorganisms from diabetic foot ulcers. Following the preferred reporting items for systematic reviews and meta-analysis (PRISMA), we included two eligible studies that reported isolating 122 bacteria spread across eleven (11) species using swab samples and conventional culture methods. Significant isolates included World Health Organization priority pathogens including: Enterobacter specie, Staphylococcus aureus, Klebsiella pneumoniae, and Acinetobacter specie. Methicillin resistant Staphylococcus aureus (MRSA) constituted 33.3% of Staphylococci species and 26% of all bacterial isolates while extended-spectrum beta-lactamase producing Escherichia coli and Klebsiella specie constituted 14.29% of total microbial isolates. Most bacteria showed susceptibility to Imipenem, Vancomycin, Ciprofloxacin, and Clindamycin, but resistance to Cotrimoxazole and Ampicillin was noted.

Short Conclusion

We conclude that data on the microbiology of DFUs in Uganda is scarce; however, the bioburden of DFUs in the country is similar to those in other parts of the world, and MRSA poses a challenge to antibiotic therapy. Consequently, the continued use of swab samples and conventional culture and sensitivity methods may limit the isolation, identification, and presentation of other important isolates. We recommend characterization of bacterial isolates to better understand their genetic makeup, and the development of a national guideline for managing diabetic foot infections.