L-arginine supplementation abrogates hypoxia-induced virulence of Staphylococcus aureus in a murine diabetic pressure wound model.

Diabetic foot ulcers (DFUs) are the most common complications of diabetes resulting from hyperglycemia leading to ischemic hypoxic tissue and nerve damage. Staphylococcus aureus is the most frequently isolated bacteria from DFUs and causes severe necrotic infections leading to amputations with a poor 5-year survival rate. However, very little is known about the mechanisms by which S. aureus dominantly colonizes and causes severe disease in DFUs. Herein, we utilized a pressure wound model in diabetic TALLYHO/JngJ mice to reproduce ischemic hypoxic tissue damage seen in DFUs and demonstrated that anaerobic fermentative growth of S. aureus significantly increased the virulence and the severity of disease by activating two-component regulatory systems leading to expression of virulence factors. Our in vitro studies showed that supplementation of nitrate as a terminal electron acceptor promotes anaerobic respiration and suppresses the expression of S. aureus virulence factors through inactivation of two-component regulatory systems, suggesting potential therapeutic benefits by promoting anaerobic nitrate respiration. Our in vivo studies revealed that dietary supplementation of L-arginine (L-Arg) significantly attenuated the severity of disease caused by S. aureus in the pressure wound model by providing nitrate. Collectively, these findings highlight the importance of anaerobic fermentative growth in S. aureus pathogenesis and the potential of dietary L-Arg supplementation as a therapeutic to prevent severe S. aureus infection in DFUs.IMPORTANCES. aureus is the most common cause of infection in DFUs, often resulting in lower-extremity amputation with a distressingly poor 5-year survival rate. Treatment for S. aureus infections has largely remained unchanged for decades and involves tissue debridement with antibiotic therapy. With high levels of conservative treatment failure, recurrence of ulcers, and antibiotic resistance, a new approach is necessary to prevent lower-extremity amputations. Nutritional aspects of DFU treatment have largely been overlooked as there has been contradictory clinical trial evidence, but very few in vitro and in vivo modelings of nutritional treatment studies have been performed. Here we demonstrate that dietary supplementation of L-Arg in a diabetic mouse model significantly reduced duration and severity of disease caused by S. aureus. These findings suggest that L-Arg supplementation could be useful as a potential preventive measure against severe S. aureus infections in DFUs.

The Effects of Antimicrobial Resistance and the Compatibility of Initial Antibiotic Treatment on Clinical Outcomes in Patients With Diabetic Foot Infection.

We aimed to determine pathogen microorganisms, their antimicrobial resistance patterns, and the effect of initial treatment on clinical outcomes in patients with diabetic foot infection (DFI). Patients with DFI from 5 centers were included in this multicenter observational prospective study between June 2018 and June 2019. Multivariate analysis was performed for the predictors of reinfection/death and major amputation. A total of 284 patients were recorded. Of whom, 193 (68%) were male and the median age was 59.9 ± 11.3 years. One hundred nineteen (41.9%) patients had amputations, as the minor (n = 83, 29.2%) or major (n = 36, 12.7%). The mortality rate was 1.7% with 4 deaths. A total of 247 microorganisms were isolated from 200 patients. The most common microorganisms were Staphylococcus aureus (n = 36, 14.6%) and Escherichia coli (n = 32, 13.0%). Methicillin resistance rates were 19.4% and 69.6% in S aureus and coagulase-negative Staphylococcus spp., respectively. Multidrug-resistant Pseudomonas aeruginosa was detected in 4 of 22 (18.2%) isolates. Extended-spectrum beta-lactamase-producing Gram-negative bacteria were detected in 20 (38.5%) isolates of E coli (14 of 32) and Klebsiella spp. (6 of 20). When the initial treatment was inappropriate, Klebsiella spp. related reinfection within 1 to 3 months was observed more frequently. Polymicrobial infection (p = .043) and vancomycin treatment (p = .007) were independent predictors of reinfection/death. Multivariate analysis revealed vascular insufficiency (p = .004), hospital readmission (p = .009), C-reactive protein > 130 mg/dL (p = .007), and receiving carbapenems (p = .005) as independent predictors of major amputation. Our results justify the importance of using appropriate narrow-spectrum empirical antimicrobials because higher rates of reinfection and major amputation were found even in the use of broad-spectrum antimicrobials.

The Healing Capability of Clove Flower Extract (CFE) in Streptozotocin-Induced (STZ-Induced) Diabetic Rat Wounds Infected with Multidrug Resistant Bacteria.

Treatment of diabetic foot ulcer (DFU) is of great challenge as it is shown to be infected by multidrug resistant bacteria (MDR bacteria). Sixty four bacterial isolates were isolated from DFU cases; antibiotic susceptibility tests were carried out for all of them. One bacterial isolate (number 11) was shown to resist the action of 8 out of 12 antibiotics used and was identified by both a Vitek-2 system and 16S rRNA fingerprints as belonging to Proteus mirabilis, and was designated Proteus mirabilis LC587231 (P. mirabilis). Clove flower extract (CFE) inhibited distinctively the P. mirabilis bacterium obtained. GC-MS spectroscopy showed that this CFE contained nine bioactive compounds. The effect of CFE on wound healing of Type 1 diabetic albino rats (Rattus norvegicus) was studied. The results indicated that topical application of CFE hydrogel improved wound size, wound index, mRNA expression of the wound healing markers (Coli1, MMP9, Fibronectin, PCNA, and TGFß), growth factor signaling pathways (PPAR-α, PGC1-α, GLP-1, GLPr-1, EGF-ß, EGF-ßr, VEGF-ß, and FGF-ß), inflammatory cytokine expression (IL8, TNFα, NFKß, IL1ß, and MCP1), as well as anti-inflammatory cytokines (IL4 & IL10), pro-apoptotic markers (FAS, FAS-L, BAX, BAX/BCL-2, Caspase-3, P53, P38), as well as an antiapoptotic one (BCL2). Furthermore, it improved the wound oxidative state and reduced the wound microbial load, as the cefepime therapy improved the wound healing parameters. Based on the previous notions, it could be concluded that CFE represents a valid antibiotics alternative for DFU therapy since it improves diabetic wound healing and exerts antibacterial activity either in vitro or in vivo.

Ozone Therapy on Reduction of Bacterial Colonies and Acceleration of Diabetic Foot Ulcer Healing.

Diabetic foot ulcers (DFUs) are highly vulnerable to infection and pose risk for limb amputations. Studies have shown that ozone therapy reduces wound size and improves wound healing time better than standard treatments. We examined the effectiveness of combining standard wound care with ozone therapy to reduce bacterial colonization and accelerate healing of DFUs in the home care setting. The control group (n = 12) received standard wound care with antimicrobial dressings every 3 days for 21 days, and the intervention group (n = 15) received the same as control group plus ozone bagging therapy at 70 µg/mL for 10 minutes every 3 days for 21 days. Combining standard wound care with ozone therapy significantly decreased the number of bacterial colonies (p = 0.001). However, no significant difference in DFU assessment score was found between the intervention and control groups (p > 0.05). Combining standard wound care with ozone therapy reduced the number of bacteria in the DFUs but exerted no significant effect on wound healing. Future studies should examine the administration of ozone therapy with different concentrations and times of exposure to explore the right dose for healing DFUs.

Hypertonic glucose inhibits growth and attenuates virulence factors of multidrug-resistant Pseudomonas aeruginosa.

BACKGROUND: Pseudomonas aeruginosa is the most common Gram-negative pathogen responsible for chronic wound infections, such as diabetic foot infections, and further exacerbates the treatment options and cost of such conditions. Hypertonic glucose, a commonly used prolotherapy solution, can accelerate the proliferation of granulation tissue and improve microcirculation in wounds. However, the action of hypertonic glucose on bacterial pathogens that infect wounds is unclear. In this study, we investigated the inhibitory effects of hypertonic glucose on multidrug-resistant P. aeruginosa strains isolated from diabetic foot infections. Hypertonic glucose represents a novel approach to control chronic wound infections caused by P. aeruginosa. RESULTS: Four multidrug-resistant P. aeruginosa clinical strains isolated from diabetic foot ulcers from a tertiary hospital in China and the reference P. aeruginosa PAO1 strain were studied. Hypertonic glucose significantly inhibited the growth, biofilm formation, and swimming motility of P. aeruginosa clinical strains and PAO1. Furthermore, hypertonic glucose significantly reduced the production of pyocyanin and elastase virulence factors in P. aeruginosa. The expression of major quorum sensing genes (lasI, lasR, rhlI, and rhlR) in P. aeruginosa were all downregulated in response to hypertonic glucose treatment. In a Galleria mellonella larvae infection model, the administration of hypertonic glucose was shown to increase the survival rates of larvae infected by P. aeruginosa strains (3/5). CONCLUSIONS: Hypertonic glucose inhibited the growth, biofilm formation, and swimming motility of P. aeruginosa, as well as reduced the production of virulence factors and quorum sensing gene expression. Further studies that investigate hypertonic glucose therapy should be considered in treating chronic wound infections.

Microbiologic characteristics and antibiotic resistance rates of diabetic foot infections.

PURPOSE: the purpose of this research was to identify the sociodemographic and microbiological characteristics and antibiotic resistance rates of patients with diabetic foot infections, hospitalized in an emergency reference center. METHODS: it was an observational and transversal study. The sociodemographic data were collected by direct interview with the patients. During the surgical procedures, specimens of tissue of the infected foot lesions were biopsied to be cultured, and for bacterial resistance analysis. RESULTS: the sample consisted of 105 patients. The majority of patierns were men, over 50 years of age, married and with low educational level. There was bacterial growth in 95 of the 105 tissue cultures. In each positive culture only one germ was isolated. There was a high prevalence of germs of the Enterobacteriaceae family (51,5%). Gram-negative germs were isolated in 60% of cultures and the most individually isolated germs were the Gram-positive cocci, Staphylococcus aureus (20%) and Enterococcus faecalis (17,9%). Regarding antibiotic resistance rates, a high frequency of Staphylococcus aureus resistant to methicillin (63,0%) and to ciprofloxacin (55,5%) was found; additionally, 43,5% of the Gram-negative isolated germs were resistant to ciprofloxacin. CONCLUSIONS: the majority of patients were men, over 50 years of age, married and with low educational level. The most prevalent isolated germs from the infected foot lesions were Gram-negative bacteria, resistant to ciprofloxacin, and the individually most isolated germ was the methicillin resistant Staphylococcus aureus.

Clinical and bacteriological profile of diabetic foot infections in a tertiary care.

BACKGROUND: Diabetic foot infection is a worldwide health problem is commonly encountered in daily practice. This study was conducted to identify the microbiological profile and antibiotic sensitivity patterns of causative agents identified from diabetic foot infections (DFIs). In addition, the assessment included probable risk factors contributing to infection of ulcers that harbour multidrug-resistant organisms (MDROs) and their outcomes. METHODS: We carried out a prospective analysis based on the DFI samples collected from 2016 till 2018. Specimens were cultured with optimal techniques in addition to antibiotic susceptibility based on recommendations from The Clinical and Laboratory Standards Institute (CLSI). A total of 1040 pathogens were isolated with an average of 1.9 pathogens per lesion in 550 patients who were identified with having DFIs during this interval. RESULTS: A higher percentage of Gram-negative pathogens (54%) were identified as compared with Gram-positive pathogens (33%) or anaerobes (12%). A total of 85% of the patients were found to have polymicrobial infections. Pseudomonas aeruginosa (19%), Staphylococcus aureus (11%) and Bacteroides species (8%) appeared to be the predominant organisms isolated. In the management of Gram-positive bacteria, the most efficacious treatment was seen with the use of Vancomycin, while Imipenem and Amikacin proved to be effective in the treatment of Gram-negative bacteria. CONCLUSION: DFI's are common among Malaysians with diabetes, with a majority of cases displaying polymicrobial aetiology with multi-drug resistant isolates. The data obtained from this study will be valuable in aiding future empirical treatment guidelines in the treatment of DFIs. This study investigated the microbiology of DFIs and their resistance to antibiotics in patients with DFIs that were managed at a Tertiary Care Centre in Malaysia.

Inducing type 2 immune response, induction of angiogenesis, and anti-bacterial and anti-inflammatory properties make Lacto-n-Neotetraose (LNnT) a therapeutic choice to accelerate the wound healing process.

The healing process of non-healing and full-thickness wounds is currently facing some serious challenges. In such ulcers, losing a large part of skin causes a chronic infection due to the entrance of various pathogens in the wound bed. Moreover, poor vascularization, uncontrolled inflammation, and delayed re-epithelialization increase the healing time in patients suffering from such wounds. In this light, tissue engineering provides a wide range of strategies using a variety of biomaterials, biofactors and stem cells to decrease the healing time and restore the function of the damaged site. A suitable wound healing agent should possess some critical parameters such as inducing re-epithelialization, anti-inflammatory and anti-bacterial properties, and angiogenic capability. The Lacto-n-Neotetraose (LNnT) with chemical formula C26H45NO21 is an oligosaccharide present in human milk and soluble antigens extracted from Schistosoma mansoni eggs. It is reported that LNnT induces type 2 immune response (Th2 immunity). Th2 immunity promotes re-epithelialization, angiogenesis and wound contraction by recruiting the cells which produce Th2-related cytokines. Moreover, LNnT shows some special characteristics such as angiogenic capability, anti-inflammatory, and anti-bacterial effects which can address the mentioned challenges in the treatment of non-healing and full-thickness wounds. Here, we hypothesize that utilizing LNnT is an appropriate biofactor which would improve the healing process in full-thickness and non-healing wounds.

Microbiologic characteristics and antibiotic resistance rates of diabetic foot infections / Perfil microbiológico e de resistência bacteriana no pé diabético infectado

ABSTRACT Purpose: the purpose of this research was to identify the sociodemographic and microbiological characteristics and antibiotic resistance rates of patients with diabetic foot infections, hospitalized in an emergency reference center. Methods: it was an observational and transversal study. The sociodemographic data were collected by direct interview with the patients. During the surgical procedures, specimens of tissue of the infected foot lesions were biopsied to be cultured, and for bacterial resistance analysis. Results: the sample consisted of 105 patients. The majority of patierns were men, over 50 years of age, married and with low educational level. There was bacterial growth in 95 of the 105 tissue cultures. In each positive culture only one germ was isolated. There was a high prevalence of germs of the Enterobacteriaceae family (51,5%). Gram-negative germs were isolated in 60% of cultures and the most individually isolated germs were the Gram-positive cocci, Staphylococcus aureus (20%) and Enterococcus faecalis (17,9%). Regarding antibiotic resistance rates, a high frequency of Staphylococcus aureus resistant to methicillin (63,0%) and to ciprofloxacin (55,5%) was found; additionally, 43,5% of the Gram-negative isolated germs were resistant to ciprofloxacin. Conclusions: the majority of patients were men, over 50 years of age, married and with low educational level. The most prevalent isolated germs from the infected foot lesions were Gram-negative bacteria, resistant to ciprofloxacin, and the individually most isolated germ was the methicillin resistant Staphylococcus aureus.

RESUMO Objetivo: identificar o perfil sociodemográfico, microbiológico e de resistência bacteriana em pacientes com pé diabético infectado. Métodos: tratou-se de estudo observacional, transversal que avaliou os perfis sóciodemográfico e microbiológico de pacientes portadores de pé diabético infectado internados em Pronto Socorro de referência. Os dados sociodemográficos foram coletados por meio de entrevista. Foram colhidos, durante os procedimentos cirúrgicos, fragmentos de tecidos das lesões podais infectadas para realização de cultura/antibiograma. Resultados: a amostra foi composta por 105 pacientes. O perfil sociodemográfico mais prevalente foi o de pacientes do sexo masculino, acima dos 50 anos, casados e com baixa escolaridade. Das 105 amostras de fragmentos de tecidos colhidos para realização de cultura e antibiograma, 95 foram positivas, com crescimento de um único germe em cada um dos exames. Houve predomínio de germes da família Enterobacteriaceae (51,5%). Germes Gram-negativos foram isolados em 60,0% das culturas e os espécimes mais isolados individualmente foram os cocos Gram-positivos, Staphylococcus aureus (20,0%) e Enterococcus faecalis (17,9%). Considerando-se os perfis de resistência bacteriana, verificou-se alta taxa de Staphylococcus aureus resistente à meticilina (63,0%) e à ciprofloxacino (55,5%); verificou-se, também, que 43,5% dos germes Gram-negativos eram resistentes à ciprofloxacino. Conclusões: o perfil sociodemográfico majoritário, foi o de homens, com mais de 50 anos e com baixa escolaridade. Concluímos que os germes mais prevalentes nas lesões podais dos pacientes diabéticos foram os Gram-negativos, resistentes ao ciprofloxacino e que o germe mais isolado individualmente foi o Staphylococcus aureus resistente à meticilina.

Isolation and antibiotic sensitivity pattern of drug resistant bacteria in ulcerative foot of type 2 diabetic patients.

The present study aimed to decipher the bacterial infections in diabetic foot human patients in Pakistan and the anti-microbial susceptibility for clinical relevance. A total of 30 samples were collected from hospitalized type 2 diabetic patients (men and women) having foot ulcers. The collected samples were cultured on mannitol salt agar, Blood agar and MacConkey's agar and cetrimide agar. Gram staining and specific biochemical tests were performed to identify the invading bacteria. Antibiotic sensitivity and resistance pattern was performed for isolated bacteria by Kirby-Bauer disc diffusion method. In diabetic foot ulcers, most prevalent bacteria were S. aureus with percent positivity of 83% followed by E. coli (66%), K. pneumoniae (40%) and P. aeruginosa (16%). The infected ulcer with poly-microorganisms was 83.4% and the infected ulcer with single isolates was 16.6%. Imipenem was found to be most sensitive antibiotic against Gram positive as well as Gram negative bacterial isolates from diabetic foot ulcer human patients. Gram negative isolates from diabetic foot showed resistance to ampicillin, sulfamethoxazole/trimethoprim, cefotaxime/clavulanate, metronidazole. The diabetic foot ulcers of human patients revealed high prevalence of S. aureus followed by E. coli, K. pneumoniae and P. aeruginosa respectively. Imipenem was found to be the most sensitive antibiotic for all the bacterial isolates from foot ulcers of type 2 diabetic patients. This study suggests imipenem as effective antibiotic for treatment of diabetic foot ulcers against bacteria.

Microbiology of diabetic foot infections in three district hospital in Malaysia and comparison with South East Asian Countries.

INTRODUCTION: Diabetic foot infection, a complication that is associated with lower-limb amputation, incurs a huge economic burden to the hospital and health care system of Malaysia. The bacteriological profile of pathogens in diabetic foot infections in Malaysia has been sparsely studied. We investigated the microbiology of diabetic foot infections in patients admitted to the district hospitals on the east coast of Malaysia. METHODS: A retrospective analysis was conducted in three district hospitals (Hospital Kuala Lipis, Hospital Bentong and Hospital Raub) in Malaysia from 1st of January 2016 to 31st December 2016. The clinical specimens were cultured using Clinical and Laboratory Standards Institute (CLSI) guidelines. Antibiotic sensitivity testing to different antibiotics was carried out using the disc diffusion method. RESULT: A total of 188 pathogens were isolated from 173 patients, with an average of 1.09 pathogens per lesion. Majority of the pathogens isolated were gram negative pathogens (73.4%). The most commonly isolated pathogens were Staphylococcus aureus (17.5%). This was followed by Klebsiella spp. (17%), Pseudomonas spp. (15.4%) and Proteus spp. (13.8%). Gram positive pathogens were sensitive to most of the antibiotics tested except penicillin and fusidic acid. Gram negative pathogens were sensitive to all antibiotics tested except ampicillin and amoxicillin/clavulanic acid. Amikacin provide coverage for all gram negative pathogens in DFI. CONCLUSION: For the management of patient with infection in diabetic foot, the choice of antibiotic therapy depends on the sensitivity of the pathogens, the severity of the infection, the patient's allergies history, toxicity and excretion of the antibiotics.

[Infections in diabetic foot. Choice of empirical antibiotic regimen]. / Infecciones en pie diabético. Elección del tratamiento antibiótico empírico.

Diabetic foot infections are related to severe complications and constitute the main reason for diabetes-related hospitalization and lower limb amputations. A diabetic foot infection requires prompt actions to avoid progression of the infected wound; a soft tissue sample has to be taken for microbiological culture and empiric antibiotic therapy must be started immediately. Empiric antibiotic schemes should be chosen based on the severity of the infection and the local prevalence of microbial causal agents. Therefore, it is important to monitor these indicators. The aim of this study was to determine which microorganisms were more prevalent in cultures of diabetic foot infections during 2018 and what antibiotic combination was better to cover local microbiology, compared with data available from 2015 for a similar cohort. A total of 68 positive cultures were obtained of 72 soft tissue specimens analyzed. The most frequent microorganisms were Gram negative (47.1%), and resulted significantly more frequent than in 2015 (24.6%) p = 0.01. These Gram negative germs also resulted more sensitive to ciprofloxacin than in 2015 (62.5% vs. 25.0%) p = 0.03. Amoxicillin-clavulanate plus ciprofloxacin was the optimal combination therapy in 2018, while in 2015 it was amoxicillin-clavulanate plus trimethoprim sulfamethoxazole. In agreement with these results, we recommend amoxicillin-clavulanate plus ciprofloxacin as the empiric antibiotic regimen of choice for soft tissue infections in diabetic foot. We consider surveillance of local microbiology to be an important tool in the management of diabetic foot infections.

Las infecciones del pie diabético se asocian a complicaciones graves y constituyen la principal causa de hospitalización relacionada con diabetes y amputación de miembros inferiores. Para evitar su progresión, se requiere una conducta inicial rápida y adecuada que incluye toma de muestras para cultivos e inicio inmediato de tratamiento antibiótico empírico, según las características de las lesiones y la prevalencia local de microorganismos. Por ello, es necesario conocer y vigilar la microbiología local y la resistencia a los antimicrobianos. El objetivo de este trabajo fue describir la frecuencia de gérmenes en infecciones de pie diabético en pacientes ambulatorios asistidos en nuestro hospital en 2018 e identificar el esquema antibiótico con mayor cobertura, en comparación con los resultados de un estudio similar realizado en 2015. Fueron analizadas 72 muestras tomadas mediante punción por piel sana de partes blandas. Entre los 68 gérmenes aislados, los Gram negativos fueron los más frecuentes (47.1%), lo que representa un aumento significativo en relación a la frecuencia observada en 2015 (24.6%) p = 0.01 y un aumento de la sensibilidad a ciprofloxacina de 25% a 62.5% (p=0.03). El esquema con mayor cobertura fue amoxicilina-clavulánico con ciprofloxacina (77.9%) mientras que en 2015 fue amoxicilina-clavulánico con trimetoprima sulfametoxazol. La vigilancia de la microbiología local es fundamental para la elección del antibiótico empírico en las infecciones de pie diabético. En nuestro hospital, cuando la infección es de partes blandas, se recomienda la combinación amoxicilina-clavulánico más ciprofloxacina como esquema antibiótico empírico según los hallazgos de este estudio.

Infecciones en pie diabético: Elección del tratamiento antibiótico empírico / Infections in diabetic foot. Choice of empirical antibiotic regimen

Las infecciones del pie diabético se asocian a complicaciones graves y constituyen la principal causa de hospitalización relacionada con diabetes y amputación de miembros inferiores. Para evitar su progresión, se requiere una conducta inicial rápida y adecuada que incluye toma de muestras para cultivos e inicio inmediato de tratamiento antibiótico empírico, según las características de las lesiones y la prevalencia local de microorganismos. Por ello, es necesario conocer y vigilar la microbiología local y la resistencia a los antimicrobianos. El objetivo de este trabajo fue describir la frecuencia de gérmenes en infecciones de pie diabético en pacientes ambulatorios asistidos en nuestro hospital en 2018 e identificar el esquema antibiótico con mayor cobertura, en comparación con los resultados de un estudio similar realizado en 2015. Fueron analizadas 72 muestras tomadas mediante punción por piel sana de partes blandas. Entre los 68 gérmenes aislados, los Gram negativos fueron los más frecuentes (47.1%), lo que representa un aumento significativo en relación a la frecuencia observada en 2015 (24.6%) p = 0.01 y un aumento de la sensibilidad a ciprofloxacina de 25% a 62.5% (p=0.03). El esquema con mayor cobertura fue amoxicilina-clavulánico con ciprofloxacina (77.9%) mientras que en 2015 fue amoxicilina-clavulánico con trimetoprima sulfametoxazol. La vigilancia de la microbiología local es fundamental para la elección del antibiótico empírico en las infecciones de pie diabético. En nuestro hospital, cuando la infección es de partes blandas, se recomienda la combinación amoxicilina-clavulánico más ciprofloxacina como esquema antibiótico empírico según los hallazgos de este estudio.

Diabetic foot infections are related to severe complications and constitute the main reason for diabetes-related hospitalization and lower limb amputations. A diabetic foot infection requires prompt actions to avoid progression of the infected wound; a soft tissue sample has to be taken for microbiological culture and empiric antibiotic therapy must be started immediately. Empiric antibiotic schemes should be chosen based on the severity of the infection and the local prevalence of microbial causal agents. Therefore, it is important to monitor these indicators. The aim of this study was to determine which microorganisms were more prevalent in cultures of diabetic foot infections during 2018 and what antibiotic combination was better to cover local microbiology, compared with data available from 2015 for a similar cohort. A total of 68 positive cultures were obtained of 72 soft tissue specimens analyzed. The most frequent microorganisms were Gram negative (47.1%), and resulted significantly more frequent than in 2015 (24.6%) p = 0.01. These Gram negative germs also resulted more sensitive to ciprofloxacin than in 2015 (62.5% vs. 25.0%) p = 0.03. Amoxicillin-clavulanate plus ciprofloxacin was the optimal combination therapy in 2018, while in 2015 it was amoxicillin-clavulanate plus trimethoprim sulfamethoxazole. In agreement with these results, we recommend amoxicillin-clavulanate plus ciprofloxacin as the empiric antibiotic regimen of choice for soft tissue infections in diabetic foot. We consider surveillance of local microbiology to be an important tool in the management of diabetic foot infections.

Diabetic Foot Infection: Causative Pathogens and Empiric Antibiotherapy Considerations-The Experience of a Tertiary Center.

Most moderate-to-severe diabetic foot infections (DFIs) require hospitalization with urgent surgical approach and administration of empiric antibiotherapy. To ensure optimal antibiotic coverage, regular microbiological background updates are imperative. The purpose is to characterize the microbiological profile and the antibiotic sensitivity pattern of the DFI causative pathogens isolated within a specialized DFI unit of a tertiary hospital, in order to establish evidence-based policies regarding empirical antibiotic use. A cross-sectional study was conducted. Microbiological cultures and corresponding antibiotic sensitivity tests collected from moderate-to-severe DFIs as a first approach to the hospitalized patient were retrieved and analyzed during a 12-month period. Two groups were analyzed: inpatients that had been previously followed at the diabetic foot clinic of the hospital and inpatients without a previous contact with the hospital services. A total of 125 isolates obtained from 87 patients were deemed for analysis. Globally, a predominance of Gram-positive bacteria was observed (60%). Staphylococcus aureus was the most common pathogen. The global ratio of methicillin-sensitive S aureus to methicillin-resistant S aureus (MRSA) was 1.3:1, with similar findings in both groups. According to the antibiotic sensitivity test results, and within the recommended empiric antibiotic regimens for DFI, piperacillin/tazobactam seems to be the most suitable option. Gram-positive bacteria prevail as the main isolates in DFIs. Screening for MRSA-specific risk factors is mandatory. When going for a first empiric therapy, piperacillin/tazobactam is recommended in this institution, and an anti-MRSA agent should be added early, if necessary. We encourage continuous monitoring for the bacterial prevalence in Portuguese diabetic foot centers as it is paramount for the decision making regarding DFI protocols.

Bacterial isolation and antibiotic susceptibility from diabetic foot ulcers in Kenya using microbiological tests and comparison with RT-PCR in detection of S. aureus and MRSA.

OBJECTIVES: Diabetic foot ulcers (DFUs) often lead to hospital admissions, amputations and deaths; however, there is no up-to-date information on microbial isolates from DFUs and no mention of utilization of molecular techniques in Sub-Saharan Africa. We conducted a cross-sectional study among 83 adult patients at a tertiary hospital in Kenya over 12 months. The study aimed to isolate, identify bacteria, their antibiotic susceptibility patterns in active DFUs, and to compare standard microbiological methods versus a real-time PCR commercial kit in the detection of Staphylococcus aureus DNA and methicillin-resistant S. aureus (MRSA) DNA. RESULTS: Eighty swabs (94%) were culture-positive; 29% were Gram-positive and 65% were Gram-negative. The main organisms isolated were S. aureus (16%), Escherichia coli (15%), Proteus mirabilis (11%), Klebsiella pneumoniae (7%) and Pseudomonas aeruginosa (7%). The bacterial isolates showed resistance to commonly used antibiotics such as ampicillin, amoxicillin, cefepime, ceftazidime, cefuroxime, clindamycin, erythromycin, piperacillin-tazobactam, tetracycline and trimethoprim-sulphamethoxazole (TMPSMX). Thirty-one percent of the S. aureus isolated and 40% of the Gram-negatives were multi-drug resistant organisms (MDROs). There was a high prevalence of nosocomial bacteria. MRSA were not identified using culture methods but were identified using PCR. PCR was more sensitive but less specific than culture-based methods to identify S. aureus.

In vitro antibacterial and time-kill assay of ethanolic extract of Davilla nitida bark on multidrug resistant bacteria isolated from diabetic foot lesions.

This study reported the antimicrobial activity of the bark extract of Davilla nitida on multidrug resistant bacteria isolated from Diabetic Foot Infections. Antibacterial activity of the bark extract was evaluated by agar Disk-Diffusion (DD), Broth Dilution (BD), Checkerboard and Time-kill methods. The extract showed a significant antibacterial activity against all groups of bacteria tested. BD was more sensitive for determining the antibacterial activity of the bark extract than the DD method. The bark extract inhibited the growth of bacteria with high-levels of antibiotic-resistance, such as Pseudomonas spp. (100.0%), Enterobacer spp. (88.89%), Staphylococcus aureus (54.55%), Streptococcus pneumoniae (75.0%), Staphylococcus saprophyticus (92.86%). The combination of extract with antibiotics resulted in an additive effect against most of the strains tested. Time-kill kinetics profiles of bark extract showed bactericidal and time-dependent properties. Our results suggest that the bark extract of Davilla nitida is a source of bioactive compounds, which may be useful against antibiotic-resistant bacteria.

Distribution of Microbes and Drug Susceptibility in Patients with Diabetic Foot Infections in Southwest China.

OBJECTIVE: To investigate the microbial distribution and drug susceptibility among diabetic foot ulcers (DFUs) with different Wagner grades and between acute and chronic DFUs. Methods. We enrolled 428 DFU patients who were hospitalized and treated in the Southwest Hospital. We collected deep ulcer secretion for microbial culture and drug susceptibility tests and analyzed the results. We reexamined 67 patients with poor anti-infection efficacy and analyzed microbial species. Results: The 354 positive samples included 201 cases (56.8%) of single-pathogen infections and 153 cases (43.2%) of multiple-pathogen infections before antibiotic therapy. A total of 555 strains were cultivated, including 205 (36.9%) strains of gram-positive organisms (GPOs), 283 (51.0%) gram-negative bacilli (GNB), and 67 (12.1%) fungal strains. In terms of distribution, patients with different Wagner grades had different bacterial composition ratios (P < 0.01). Patients with Wagner grades 3-5 mainly had GNB. The specimens from chronic ulcer wounds were primarily GNB (54.2%), whereas fungi accounted for 14.4% of the infections; the distribution was significantly different from that of acute ulcers (P < 0.01). The susceptibility tests showed that the Staphylococcus genus was more susceptible to vancomycin, linezolid, and tigecycline. Tobramycin was the most effective drug (97%) for the treatment of Escherichia coli, followed by ertapenem (96.4%), imipenem (93.5%), and cefotetan (90%). Most of the remaining GNB were susceptible to antibiotics such as carbapenems, aminoglycosides, fluoroquinolones, ceftazidime, cefepime, and piperacillin-tazobactam (>63.2%). After antibiotic therapy, the positive rate of microbial culture was 52.2%, and the proportion of GNB and fungi increased to 68.9% and 20%. CONCLUSION: The distribution and types of bacteria in diabetic foot infection (DFI) patients varied with the different Wagner classification grades, courses of the ulcers, and antibiotic therapy. Multidrug resistance were increased, and the clinical treatment of DFIs should select the most suitable antibiotics based on the pathogen culture and drug susceptibility test results.

Enhanced antibacterial effects of green synthesized ZnO NPs using Aristolochia indica against Multi-drug resistant bacterial pathogens from Diabetic Foot Ulcer.

BACKGROUND: Increased incidence of Multi-drug resistance in microorganisms has become the greatest challenge in the treatment of Diabetic Foot Ulcer (DFU) and urges the need of a new antimicrobial agent. In this study, we determined the bactericidal effects of ZnO nanoparticles (ZnO NPs) green synthesized from Aristolochia indica against Multi-drug Resistant Organisms (MDROs) isolated from pus samples of DFU patients attending in a tertiary care hospital in South India. METHODS: ZnO NPs were characterized by UV-vis-DRS spectroscopy, Atomic Force Microscopy (AFM), Transmission Electron Microscopy (TEM) and for its zeta potential value. MIC/MBC assays were performed to determine bactericidal or bacteriostatic effects. Time-kill assays, Protein leakage and Flow cytometric analysis evaluated bacterial cell death at 1x MIC and 2x MIC concentrations of ZnO NPs. RESULTS: ZnO NPs of size 22.5nm with a zeta potential of -21.9±1mV exhibited remarkable bactericidal activity with MIC/MBC ranging from 25 to 400µg/ml with a significant reduction in viable count from 2h onwards. Protein leakage and Flow cytometric analysis confirmed bacterial cell death due to ZnO NPs. CONCLUSION: This study concluded that green synthesis protocol offers reliable, eco-friendly approach towards the development of antimicrobial ZnO NPs to combat antibiotic drug resistance.