Bacteriology of moderate-to-severe diabetic foot infections in two tertiary hospitals of Iran

Microbiological Pattern, Antimicrobial Resistance and Prevalence of MDR/XDR Organisms in Patients With Diabetic Foot Infection in an Indian Tertiary Care Hospital

Foot infections are the most prevalent problem in persons with diabetes. The burden of multidrug resistant (MDR) microorganisms in diabetic foot infections (DFIs) is rising day by day. Given that, the present study aims to determine the variety of microorganisms isolated from the diabetic foot ulcers (DFUs), and their antibiotic sensitivity pattern. This prospective observational study was conducted for 1 year at Bharati Hospital and Research Centre, Pune, India. Clinically infected patients with DFU admitted to the surgery ward were included in this study. The specimen for microbiological studies is obtained from the wound swabs, soft tissue, and bone tissue as a part of routine clinical care. All demographic, clinical data, microbial culture results were collected, and evaluated for each case. Antimicrobial susceptibility testing to different agents was carried out using the VITEK-2® machine. A total of 110 microorganisms were isolated from 76 specimens, with an average of 1.4 organisms per lesion. Staphylococcus aureus (n = 27, 24.5%) and Escherichia coli (n = 17, 15.4%) were the most prevalent Gram-positive and Gram-negative organisms isolated, respectively. MDR organisms constituted up to 52 (47.2%), while 6 (5.4%) of the samples were extensively drug resistant (XDR). Methicillin-resistant S aureus (MRSA) accounted for up to 19 (70.3%) of the S aureus isolates, likewise extended-spectrum beta-lactamase producing microorganisms constituted 16 (14.5%) of total isolates in this study. Oxacillin and benzyl penicillin exhibited least susceptibility against Gram-positive bacteria, among Gram-negative organisms; cefuroxime, ceftriaxone, and ciprofloxacin were least sensitive. As most of the S aureus isolate in our study was MRSA, empirical antimicrobial therapy may include coverage for MRSA in a patient with risk factors associated with this pathogen. A crucial observation is the presence of XDR strains of Proteus mirabilis in DFIs, which is resistant to almost all the antimicrobials, tested. Appropriate antimicrobial selection may reduce the morbidity and the emergence of MDR organisms in DFIs.

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

The number of diabetic foot ulcer patients is substantially increasing, with the rapidly rising burden of diabetic mellitus in sub-Saharan Africa. The data on the regional prevalence of diabetic foot ulcer infecting bacteria and their antimicrobial resistance patterns is crucial for its proper management. This systematic review and meta-analysis determined the pooled prevalence of bacterial profiles and antimicrobial resistance patterns of infected diabetic foot ulcers in sub-Saharan Africa. A comprehensive search of the literature was performed on CINAHL, EMBASE, Google Scholar, PubMed, Scopus, and Web of Science databases. Critical appraisal was done using the Joanna Briggs Institute's tool for prevalence studies. A pooled statistical meta-analysis was conducted using STATA Version 17.0. The I2 statistics and Egger's test were used to assess the heterogeneity and publication bias. The pooled prevalence and the corresponding 95% confidence interval of bacterial profiles and their antimicrobial resistance patterns were estimated using a random effect model. Eleven studies with a total of 1174 study participants and 1701 bacteria isolates were included. The pooled prevalence of the most common bacterial isolates obtained from DFU were S. aureus (34.34%), E. coli (21.16%), and P. aeruginosa (20.98%). The highest pooled resistance pattern of S. aureus was towards Gentamicin (57.96%) and Ciprofloxacin (52.45%). E.coli and K. Pneumoniae showed more than a 50% resistance rate for the most common antibiotics tested. Both gram-positive and gram-negative bacteria were associated with diabetic foot ulcers in sub-Saharan Africa. Our findings are important for planning treatment with the appropriate antibiotics in the region. The high antimicrobial resistance prevalence rate indicates the need for context-specific effective strategies aimed at infection prevention and evidence-based alternative therapies.

Diabetic foot ulcer-a systematic review on relevant microbial etiology and antibiotic resistance in Asian countries

BACKGROUND AND AIMS

Diabetic foot ulcer (DFU) is one of the most common but uncontrolled health issues of diabetic patients that needs more therapeutic considerations. This systematic review aims to study the current status of the etiological agents responsible for DFU, their frequency in some of the most occurring Asian countries, and their antibiotic resistance pattern based on available studies.

METHODS

Here, the literature survey was conducted on all the DFU studies with the records of etiological agents and conventional therapeutic treatment published until March 2021 using Medical Literature Analysis and Retrieval System Online (MEDLINE) and Web of Science Core Collection (WoSCC) database.

RESULTS

Overall, in our study, a total of 73 studies representing 12 Asian countries worldwide have been included. We found that the highest number of studies were reported from India (45%) followed by Pakistan (11%), China, Iran and others. 71% of recent studies reported DFU being attributed to poly-microbial infections while the dominant position was significantly secured by Gram- negative bacteria (77%, p = 0.34). Staphylococcus aureus was found to be the most prevalent isolate followed by Pseudomonas and then Escherichia coli (mean value - 22%, 17%, and 15% respectively). Antibiotic sensitivity pattern was determined based on availability in terms of median resistance (MR) and interquartile range (IQR) which showed the growing resistance developed by both Gram-positive and Gram-negative isolates. Gram positive pathogens were still reported as susceptible to vancomycin (MR 0%, IQR 0-22.8%), linezolid (MR 0%, IQR 0-15.53%) and imipenem (MR 11%, IQR 0-23.53%). Carbapenem genera, colistin, and amikacin were the most effective drugs against Gram-negative pathogens.

CONCLUSION

The findings of this study highly recommend searching for alternative and complementary therapeutic regimens instead of prescribing conventional drugs blindly without investigating the progression of the stages of the ulcer, which may help reduce the medical and economic burden of this disease.

Relative Abundance and Detection of Pseudomonas aeruginosa from Chronic Wound Infections Globally

Pseudomonas aeruginosa is a difficult-to-treat pathogen that is frequently involved with chronic wound infections. Here, we conducted a literature search of world-wide studies published between 2005 and 2022 that described the microbiological profiles of chronic wound infections. For each continent, a hierarchy of pathogens was created to define the organisms that were most frequently isolated in each region. Except for South America, P. aeruginosa was the second most common organism in each major continent, with Staphylococcus aureus being the most abundant pathogen overall. When individual countries were evaluated, P. aeruginosa was the most frequently isolated organism in several Southeast Asia nations including India and Malaysia. P. aeruginosa was less commonly isolated from diabetic foot infections in North America, Europe, and Africa in comparison to other types of chronic wound infections. Additionally, the Levine wound swab technique may be a quick and painless way to isolate P. aeruginosa from wound infections, but the isolation of P. aeruginosa does not seem to be an informative predictor of the patient's clinical course. A multivariate risk assessment that accounts for the regional frequency of P. aeruginosa isolation may be an appropriate way to guide empiric management of chronic wound infections.

Molecular Characteristics of Staphylococcus aureus Strains Isolated from Nasal Cavity and Wound Infections Among Diabetic Patients

Staphylococcus aureus is the most common pathogen contributing to diabetic foot infections (DFI). Nasal transmission of S. aureus potentially increases the risk of endogenous infection. The aim of this study was to determine the genetic diversity and antibiotic resistance profile of S. aureus isolates in nasal and wound samples from diabetic patients. A cross-sectional study was conducted from July 2018 to September 2019. S. aureus was isolated from the anterior nares and wounds of diabetic patients. All S. aureus isolates were characterized by detection of resistance and virulence genes (mecA, ermA, ermC, hla, hlb, hlg, sea, lukDE, pvl), staphylococcal cassette chromosome mec (SCCmec)-typing and staphylococcal protein A (spa)-typing. A total of 34 S. aureus were isolated from the wounds of 115 diabetic patients with DFI. Twenty-four S. aureus isolates were collected from the anterior nares of patients, and thirteen patients had concurrent S. aureus in nasal and wound specimens. The prevalence of methicillin-resistant S. aureus (MRSA) in nasal specimens was noticeable (41.7%), and the most common spa-type in nasal and wound specimens was t14870. Nearly half of the patients with concurrent S. aureus in wound and nasal specimens had similar isolates from both sites. Our data suggest that detection and screening of S. aureus colonization in the nasal cavity may prevent subsequent endogenous infections, particularly with MRSA strains.

Fig latex inhibits the growth of pathogenic bacteria invading human diabetic wounds and accelerates wound closure in diabetic mice

Impaired wound healing is one of the most critical complications associated with diabetes mellitus. Infections and foot ulcers are major causes of morbidity for diabetic patients. The current treatment of diabetic foot ulcers, commonly used antibiotics, is associated with the development of bacterial resistance. Hence, novel and more effective natural therapeutic antibacterial agents are urgently needed and should be developed against the pathogenic bacteria inhabiting diabetic wounds. Therefore, the current study aimed to investigate the impact of fig latex on pathogenic bacteria and its ability to promote the healing process of diabetic wounds. The pathogenic bacteria were isolated from patients with diabetic foot ulcers admitted to Assiut University Hospital. Fig latex was collected from trees in the Assiut region, and its chemical composition was analyzed using GC‒MS. The antibacterial efficacy of fig latex was assessed on the isolated bacteria. An in vivo study to investigate the effect of fig latex on diabetic wound healing was performed using three mouse groups: nondiabetic control mice, diabetic mice and diabetic mice treated with fig latex. The influence of fig latex on the expression levels of β-defensin-1, PECAM-1, CCL2 and ZO-1 and collagen formation was investigated. The GC‒MS analysis demonstrated the presence of triterpenoids, comprising more than 90% of the total latex content. Furthermore, using a streptozotocin-induced diabetic mouse model, topical treatment of diabetic wound tissues with fig latex was shown to accelerate and improve wound closure by increasing the expression levels of β-defensin-1, collagen, and PECAM-1 compared to untreated diabetic wounds. Additionally, fig latex decreased the expression levels of ZO-1 and CCL2.

Prevalence of Extended-Spectrum β-Lactamase and Carbapenemase Producers of Gram-Negative Bacteria, and Methicillin-Resistant Staphylococcus aureus in Isolates from Diabetic Foot Ulcer Patients in Ethiopia

Background

Infectious diabetic foot ulcers (IDFU) are a widespread health issue that affects people all over the world. IDFU, like other medical disorders, can have negative implications if drug resistance develops. Clinicians will be able to choose the optimal antibiotics to treat impacted patients based on the antibiotic susceptibility pattern of bacterial strains. In this project, we attempted to evaluate the levels of extended-spectrum beta-lactamase (ESBL), carbapenemase, and MRSA in patients with diabetic foot ulcers.

Methods

A sterile swab was used to collect a sample from the leg ulcer, while a sterile needle was used to collect the aspirated pus. Bacteria identification and antibiotic susceptibility tests are carried out based on conventional bacterial culture. The double-disc inactivation method and modified carbapenem (meropenem) were used to screen the production of ESBL and carbapenemase.

Results

Of the 76 isolates tested, 53.9% (41/76) were phenotypically ESBL producers. K. pneumoniae 75% (6/8), Acinetobacter species 75% (9/12), Serratia species 75% (3/4), Pseudomonas species 64.3% (14/9), E. coli 57.8% (11/19), Citrobacter species 50% (2/4) and Proteus mirabilis 25% (1/4) had the highest frequency of ESBL production. Of the 68 GNB isolates tested, 27.9% (19/68) were carbapenemase-producing organisms. K. pneumoniae 62.5% (5/8), Serratia 50% (3/6), Acinetobacter species 40% (4/10), Pseudomonas species 23.5% (4/17) and E. coli 15.8% (3/19) are the top five major carbapenemase producers. In this study, 32 isolates of Staphylococcus aureus were tested for methicillin resistance. Among them, 81.3% (26/32) were methicillin-resistant Staphylococcus aureus (MRSA), and 18.7% (6/32) of the remaining isolates were methicillin-sensitive Staphylococcus aureus (MSSA).

Conclusion

The result draws attention to the management of diabetic foot ulcer infections based on the results of microbiological analysis and drug susceptibility testing.

Evaluation of antibiotic resistance of Helicobacter pylori bacteria obtained from gastric biopsy samples: A cohort study

Objective

Helicobacter pylori infection is associated with a wide range of gastrointestinal diseases and is very common in developing countries. Overuse and self-prescribed antibiotics have led to antibiotic resistance and failure of complete eradication of the bacterium. The aim of this study is to evaluate the antibiotic resistance of h. pylori from samples obtained from gastric biopsy.

Methods

In this descriptive-analytical study was performed on 205 patients’ samples positive for h. pylori infection. Following h. pylori testing, the sample were culture with different antibiotics to obtain data regarding the resistance. Demographic information of the patients such as age, sex, employment status, area of residence and patient-related factors such as reason for referral, and previous history of treatment were obtained and evaluated for the correlation with antibiotic resistance.

Results

In this study, the mean age of the subjects was 42.32 ± 16.65 years. The most common reason for referral of patients in the present study was epigastric pain in 49.3% (101 patients). Antibiotic resistance to amoxicillin was 46.8%, tetracycline was 41%, metronidazole was 33.2%, clarithromycin was 70.7%. levofloxacin was 36.1% and bismuth was 19.5%. Sex, age, type of living (rural or urban), employment, reason for referral and history of treatment was not associated with any antibiotic resistance, p > 0.05.

Conclusion

Our study showed that clarithromycin resistance is the most common in our population followed by amoxicillin and tetracycline. Excessive use of these antibiotics and self-prescription should be analyzed in future studies and public-awareness programs might be required.

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H.pylori infection is associated with a wide range of gastrointestinal diseases.

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Self-prescribed antibiotics have led to antibiotic resistance and failure of complete eradication.

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Clarithromycin resistance is the most common in our population followed by amoxicillin and tetracycline.

Chronic wound isolates and their minimum inhibitory concentrations against third generation cephalosporins at a tertiary hospital in Uganda

Globally, the burden of chronic wound infections is likely to increase due to the rising levels of bacterial resistance to antibiotics. In the United States of America alone, more than 6.5 million chronic wounds with evidence of bacterial infection are diagnosed every year. In addition, the polymicrobial environment in chronic wound infections has been observed from several studies as a risk factor for development of resistance to many antibiotics including the third generation cephalosporins currently used in Mbarara Regional Referral Hospital for treatment of chronic wound infections. Therefore the main objective of this study was to determine the prevalence of chronic wound isolates and their minimum inhibitory concentrations (MIC) against third generation cephalosporins. This study was a cross-sectional descriptive and analytical survey of bacterial isolates from chronic wound infection among 75 study participants admitted in the surgical ward of Mbarara Regional Referral Hospital (MRRH), a tertiary Hospital in Western Uganda. Standard laboratory bacterial culture and identification techniques as well as broth microdilution method were used to isolate, identify pathogens and test for MIC respectively. We found that 69/75 study participants had samples with bacterial growth and the most prevalent pathogens isolated were staphylococcus aureus (40.6%) and Klebsiella spp. (29%). Generally, most isolates were susceptible to cefoperazone + sulbactum 2 g (Sulcef) and ceftriaxone 1 g (Epicephin). The overall prevalence of isolates in chronic wound infection among patients admitted in the surgical ward of MRRH was 92% and the most prevalent isolates were Staphylococcus aureus, Klebsiella species and proteus species respectively. The observed MIC values were higher than the CLSI clinical breakpoint, implying a decreasing trend in susceptibility of chronic wound isolates to third generation cephalosporins.

Predictors and outcomes of diabetic foot ulcer infection with ESBL-producing bacteria in a large tertiary center

OBJECTIVES

The aim of this study was to describe the predictors and outcomes of infection with extended-spectrum beta-lactamase (ESBL)-producing bacteria in patients with an acute diabetic foot infection (DFI).

METHODS

The records of patients admitted with acute DFI to a large tertiary hospital during the years 2014-2018 were reviewed. Demographic, clinical, and laboratory data were collected, as well as outcomes regarding amputations and mortality. Only cultures obtained during the first 2 weeks following admission were considered.

RESULTS

Cultures were available for 493 patients; 121 (24.5%) included bacteria suspected of being ESBL producers. Patients infected with ESBL-producing bacteria were older, more likely to have peripheral vascular disease (PVD), and had higher SINBAD and Wagner scores upon admission. They were also more likely to have been hospitalized in the recent 6 months. Major amputations were more prevalent in patients with versus without an ESBL-producing bacterial infection (30.6% vs 19.4%; P = 0.010), yet overall amputations and mortality rates were similar.

CONCLUSIONS

ESBL-producing bacteria are common pathogens in DFI, more prevalent in older patients with PVD, advanced ulcers, and recent hospitalization. They are associated with higher rates of major amputation. These considerations may support the choice of empirical antibiotic therapy in patients admitted with an acute DFI.

Bacterial Profile and Antimicrobial Resistance Patterns of Infected Diabetic Foot Ulcers in Iran: A Systematic Review and Meta-Analysis of Cross-Sectional Studies

Since infectious foot ulcers represent one of the major causes of lower-limb amputation, it calls for an appropriate action for early detection and sufficient treatment of diabetic foot infection (DFI). The present study aimed at investigating the bacterial epidemiology and antimicrobial resistance (AMR) patterns of DFIs in Iran. We have conducted a systematic search in PubMed, Embase, Web of Science, Scopus, Google Scholar, and Scientific Information Database to identify all articles reporting the proportion of different kinds of bacteria isolated from Iranian DFI samples. Quality was assessed using Joanna Briggs Institute tool. A pooled estimate of proportion with a corresponding 95% confidence interval (95% CI) was calculated using the random effect method. Fifteen studies were eligible, of which 1970 bacterial isolates were obtained from 1316 patients. The most predominant isolates recovered from DFIs was Staphylococcus aureus with a pooled proportion of 24.29% (95% CI: 20.25%, 28.57%) from which 55% (95% CI: 38%, 72%) were methicillin-resistant S. aureus (MRSA). Among Gram-negative strains, Escherichia coli had the highest proportion (17.19%; 95% CI: 13.96%, 20.68%) followed by Pseudomonas aeruginosa, 7.54% (95% CI: 4.56%, 11.14%). The highest pooled estimates of resistance against cotrimoxazole and ciprofloxacin were found in S. aureus 66% (95% CI: 48%, 82%) and E coli isolates 68% (95% CI: 51%, 84%), respectively. Our study revealed that AMR is at a high level in Iran and clinicians should be aware of bacterial resistance patterns to prescribe appropriate antibiotic regimens.

The bacteriostatic effect of controlled-flux electrolyzed acidic solution on healthy hallucal skin

BACKGROUND

There are various treatment protocols to manage the increased bacterial load in plantar ulcers. Recently, Controlled-Flux Electrolyzed Acidic Solution (CFEAS), with a pH less than 3, has appeared to be an effective option since its antimicrobial effect could help in the healing of those ulcers. In order to evaluate its potential in this sense, the aim of the present study was to compare bacterial growth on healthy hallucal skin using two types of bandaging (control and Controlled-Flux Electrolysed Acidic Solution).

MATERIAL AND METHODS

In a sample of 19 healthy subjects, two experiments were performed. In the first, for each subject, two identical hallux bandages were applied in the early morning. At random between left and right foot, either physiological saline (wetting every 2 h) was applied or nothing (control). In the second, two days later, new bandages were applied as before, but now either wetting with Controlled-Flux Electrolysed Acidic Solution (experimental, again wetting every 2 h) or nothing (control). In each experiment, the bacterial load in the nail fold was assessed at the first moment and after 10 h from standard counts of bacterial colony forming units (CFU).

RESULTS

In the first experiment, the CFU counts had increased significantly (p < 0.05) in both toes after the 10-h period. In the second experiment, while the bacterial load increased significantly (p = 0.001) from 0.68 ± 0.8 × 10⁴ CFU/cm² (the "pre" sample) to 1.3 ± 0.9 × 10⁴ CFU/cm² (the "post" sample) in the control toe, in the experimental CFEAS toe, the pre sample bacterial load was 0.61 ± 0.6 × 10⁴ CFU/cm², and the post sample 0.9 ± 0.8 × 10⁴ CFU/cm², with no significant difference between them (p = 0.221). Negative cultures were obtained in 3 cases (15.78%) of the experimental toe post sample, and equal post and pre counts in 2 cases (10.5%).

CONCLUSION

Controlled-Flux Electrolyzed Acidic Solution has an effect on healthy hallucal skin that is bacteriostatic, and in some cases bactericidal. This effect could be very helpful in treating plantar ulcers when there is a greatly increased bacterial load in the wound, thus potentially favoring the normal formation of granulation tissue in the skin and normal healing and closure of the ulcer.