Microbial profile of diabetic foot infections in Trinidad and Tobago

Association of multidrug-resistant bacteria and clinical outcomes in patients with infected diabetic foot in a Peruvian hospital: A retrospective cohort analysis

OBJECTIVE

To evaluate the association of multidrug-resistant bacteria (MDRB) and adverse clinical outcomes in patients with diabetic foot infection (DFI) in a Peruvian hospital.

MATERIALS AND METHODS

This retrospective cohort study evaluated patients treated in the Diabetic Foot Unit of a General Hospital in Lima, Peru. MDRB was defined by resistance to more than two pharmacological groups across six clinically significant genera. The primary outcome was death due to DFI complications and/or major amputation. Other outcomes included minor amputation, hospitalization, and a hospital stay longer than 14 days. Relative risks were estimated using Poisson regression for all outcomes.

RESULTS

The study included 192 DFI patients with a mean age of 59.9 years; 74% were males. A total of 80.8% exhibited MDRB. The primary outcome had an incidence rate of 23.2% and 5.4% in patients with and without MDRB, respectively (p = 0.01). After adjusting for sex, age, bone involvement, severe infection, ischemia, diabetes duration, and glycosylated hemoglobin, MDRB showed no association with the primary outcome (RR 3.29; 95% CI, 0.77-13.9), but did with hospitalization longer than 14 days (RR 1.43; 95% CI, 1.04-1.98).

CONCLUSIONS

Our study found no association between MDRB and increased mortality and/or major amputation due to DFI complications, but did find a correlation with prolonged hospitalization. The high proportion of MDRB could limit the demonstration of the relationship. It is urgent to apply continuous evaluation of bacterial resistance, implement a rational plan for antibiotic use, and maintain biosafety to confront this threat.

Anaerobes in diabetic foot infections: pathophysiology, epidemiology, virulence, and management

SUMMARYDiabetic foot infections (DFI) are a public health problem worldwide. DFI are polymicrobial, biofilm-associated infections involving complex bacterial communities organized in functional equivalent pathogroups, all including anaerobes. Indeed, multiple pathophysiological factors favor the growth of anaerobes in this context. However, the prevalence, role, and contribution of anaerobes in wound evolution remain poorly characterized due to their challenging detection. Studies based on culture reviewed herein showed a weighted average of 17% of patients with anaerobes. Comparatively, the weighted average of patients with anaerobes identified by 16S rRNA gene sequencing was 83.8%. Culture largely underestimated not only the presence but also the diversity of anaerobes compared with cultivation-independent approaches but both methods showed that anaerobic Gram-negative bacilli and Gram-positive cocci were the most commonly identified in DFI. Anaerobes were more present in deeper lesions, and their detection was associated with fever, malodorous lesions, and ulcer depth and duration. More specifically, initial abundance of Peptoniphilus spp. was associated with ulcer-impaired healing, Fusobacterium spp. detection was significantly correlated with the duration of DFI, and the presence of Bacteroides spp. was significantly associated with amputation. Antimicrobial resistance of anaerobes in DFI remains slightly studied and warrants more consideration in the context of increasing resistance of the most frequently identified anaerobes in DFI. The high rate of patients with DFI-involving anaerobes, the increased knowledge on the species identified, their virulence factors, and their potential role in wound evolution support recommendations combining debridement and antibiotic therapy effective on anaerobes in moderate and severe DFI.

What’s old is new again: Insights into diabetic foot microbiome

Diabetes is a chronic disease that is considered one of the most stubborn global health problems that continues to defy the efforts of scientists and physicians. The prevalence of diabetes in the global population continues to grow to alarming levels year after year, causing an increase in the incidence of diabetes complications and health care costs all over the world. One major complication of diabetes is the high susceptibility to infections especially in the lower limbs due to the immunocompromised state of diabetic patients, which is considered a definitive factor in all cases. Diabetic foot infections continue to be one of the most common infections in diabetic patients that are associated with a high risk of serious complications such as bone infection, limb amputations, and life-threatening systemic infections. In this review, we discussed the circumstances associated with the high risk of infection in diabetic patients as well as some of the most commonly isolated pathogens from diabetic foot infections and the related virulence behavior. In addition, we shed light on the different treatment strategies that aim at eradicating the infection.

A Retrospective Analysis of Microbiologic Profile of Foot Infections in Patients With Diabetic End-Stage Renal Disease

Objective

Individuals with diabetes and end-stage renal disease (ESRD) are at increased risk of foot ulceration and lower extremity amputation. Although risk factors and microbiologic analysis of diabetic foot infections ( DFIs) have been extensively studied, there are limited data available for this characteristic group.

Methods

Clinical, demographic, laboratory, microbiological data, and foot examination information were collected retrospectively regarding 94 patients with ESRD who were referred for DFI between 2006 and 2016 to hyperbaric oxygen therapy.

Results

In 6 of 94 patients with ESRD (mean age 60 years; 65 males [69.1%], 29 women [30.8%]; 91 undergoing hemodialysis [96.8%], one peritoneal dialysis [1%], two [2%] recent renal transplants), the lesions were bilateral; therefore, the evaluations were made over 100 DFIs. The most common pathogens isolated in deep wound cultures were Staphylococcus aureus and Pseudomonas aeruginosa, respectively, contributing to 27 (21.2%) and 16 (12.5%) of all 127 isolates. When the distribution of the isolates according to different Wagner grades were analyzed, it was found that the proportion of Gramnegative isolates increased statistically significantly with the ascending Wagner grade (P = .004).

Conclusion

DFIs indicate a serious complication associated with a high risk of amputation, prolonged antibiotic treatment, increased hospital and procedure demands, and the cost of health care, on patients with ESRD. The familiarization of causative pathogens underlying DFIs can aid the clinicians in the choice of appropriate empirical antibiotic treatment. This study emphasizes the need for greater attention to risk factors and the microbiologic profile of DFIs in this characteristic group.

Caribbean “substitution culture” is a barrier to effective treatment of persons with diabetic foot infections

Diabetes-related amputation rates are high in the Caribbean. Many authorities have identified independent risk factors for diabetes-related amputations, but cultural factors remain underappreciated. We coined the term “Caribbean substitution culture” to describe the attitude of patients with diabetic foot infections in which they refuse to access medical care, instead voluntarily choosing to substitute “bush medicines” or other alternative therapies in the place of conventional treatment. Recognizing that the Caribbean substitution culture is a barrier to effective treatment of diabetic foot infections is the first step in curbing these practices. In this paper, we discuss the issues related to the Caribbean substitution culture, including the demographics of the population at risk, the alternative therapeutic practices and potential public health strategies to combat this practice.

Staphylococcus aureus Toxins and Diabetic Foot Ulcers: Role in Pathogenesis and Interest in Diagnosis

Infection of foot ulcers is a common, often severe and costly complication in diabetes. Diabetic foot infections (DFI) are mainly polymicrobial, and Staphylococcus aureus is the most frequent pathogen isolated. The numerous virulence factors and toxins produced by S. aureus during an infection are well characterized. However, some particular features could be observed in DFI. The aim of this review is to describe the role of S. aureus in DFI and the implication of its toxins in the establishment of the infection. Studies on this issue have helped to distinguish two S. aureus populations in DFI: toxinogenic S. aureus strains (harboring exfoliatin-, EDIN-, PVL- or TSST-encoding genes) and non-toxinogenic strains. Toxinogenic strains are often present in infections with a more severe grade and systemic impact, whereas non-toxinogenic strains seem to remain localized in deep structures and bone involving diabetic foot osteomyelitis. Testing the virulence profile of bacteria seems to be a promising way to predict the behavior of S. aureus in the chronic wounds.

In-vitro diagnosis of single and poly microbial species targeted for diabetic foot infection using e-nose technology

Background

Effective management of patients with diabetic foot infection is a crucial concern. A delay in prescribing appropriate antimicrobial agent can lead to amputation or life threatening complications. Thus, this electronic nose (e-nose) technique will provide a diagnostic tool that will allow for rapid and accurate identification of a pathogen.

Results

This study investigates the performance of e-nose technique performing direct measurement of static headspace with algorithm and data interpretations which was validated by Headspace SPME-GC-MS, to determine the causative bacteria responsible for diabetic foot infection. The study was proposed to complement the wound swabbing method for bacterial culture and to serve as a rapid screening tool for bacteria species identification. The investigation focused on both single and poly microbial subjected to different agar media cultures. A multi-class technique was applied including statistical approaches such as Support Vector Machine (SVM), K Nearest Neighbor (KNN), Linear Discriminant Analysis (LDA) as well as neural networks called Probability Neural Network (PNN). Most of classifiers successfully identified poly and single microbial species with up to 90% accuracy.

Conclusions

The results obtained from this study showed that the e-nose was able to identify and differentiate between poly and single microbial species comparable to the conventional clinical technique. It also indicates that even though poly and single bacterial species in different agar solution emit different headspace volatiles, they can still be discriminated and identified using multivariate techniques.

The role of anaerobes in diabetic foot infections

Diabetic foot infections (DFI) are a common cause of morbidity and, on occasion, even mortality. Infection can be either mono- or polymicrobial, with a wide variety of potential pathogens. Anaerobes may be involved, particularly in wounds that are deeper or more chronic, and are more frequently identified when using modern molecular techniques, such as 16s PCR and pyrosequencing. It remains unclear whether the presence of anaerobes in DFI leads to more severe manifestations, or if these organisms are largely colonizers associated with the presence of greater degrees of tissue ischemia and necrosis. Commonly used empiric antibiotic therapy for diabetic foot infections is generally broad-spectrum and usually has activity against the most frequently identified anaerobes, such as Peptostreptococcus and Bacteroides species. Adequate surgical debridement and, when needed, foot revascularization may be at least as important as the choice of antibiotic to achieve a successful treatment outcome.

Adverse events in diabetic foot infections: a case control study comparing early versus delayed medical treatment after home remedies

Background

The aim of conventional medical therapy in diabetic foot infections is to control infection, thereby reducing amputation rates, infectious morbidity, and death. Any delay incurred during a trial of home remedies could allow an infection to progress unchecked, increasing the risk of these adverse outcomes. This study sought to determine the effects of delayed operative interventions and amputations in these patients.

Methods

A questionnaire study targeting all consecutive patients admitted with diabetic foot infection was carried out over 1 year. Two groups were defined, ie, a medical therapy group comprising patients who sought medical attention after detecting their infection and a home remedy group comprising those who voluntarily chose to delay medical therapy in favor of home remedies. The patients were followed throughout their hospital admissions. We recorded the duration of hospitalization and number of operative debridements and amputations performed.

Results

There were 695 patients with diabetic foot infections, comprising 382 in the medical therapy group and 313 in the home remedy group. Many were previously hospitalized for foot infections in the medical therapy (78%) and home remedy (74.8%) groups. The trial of home remedies lasted for a mean duration of 8.9 days. The home remedy group had a longer duration of hospitalization (16.3 versus 8.5 days; P<0.001), more operative debridements (99.7% versus 94.5%; P<0.001), and more debridements per patient (2.85 versus 2.45; P<0.001). Additionally, in the home remedy group, there was an estimated increase in expenditure of US $10,821.72 US per patient and a trend toward more major amputations (9.3% versus 5.2%; P=0.073).

Conclusion

There are negative outcomes when patients delay conventional medical therapy in favour of home remedies to treat diabetic foot infections. These treatments need not be mutually exclusive. We encourage persons with diabetes who wish to try home remedies to seek medical advice in addition as a part of holistic care.

Do Diabetic Foot Infections With Methicillin-Resistant Staphylococcus aureus Differ From Those With Other Pathogens?

There is controversy as to whether or not diabetic foot infections (DFIs) caused by methicillin-resistant Staphylococcus aureus (MRSA) are associated with worse outcomes than DFIs caused by other pathogens. To address this issue we performed a nonsystematic literature search of published articles in English language journals seeking studies reporting on the outcomes of DFIs related to their microbiology. We retrieved 48 articles published from 1999 to 2013 that described a total of 7771 cases of DFI. The overall proportion of DFIs with an isolate of S aureus was about 30%; just over one third of these (11% of all cases) were MRSA strains. Among the DFI cases caused by MRSA 1543 were episodes of soft tissue infections and 113 of osteomyelitis, while non-MRSA organisms caused 5761 soft tissue infections and 354 cases of osteomyelitis. Only 5 of the included articles attempted a comparison between DFI caused by MRSA and those caused by other pathogens, with no clear differences noted. The median total duration of antibiotic therapy for DFI caused by MRSA was 26 days, of which a median of 10 days was given intravenously. Only a few articles reported the proportion of patients with a recurrence, but they often did not differentiate between MRSA and non-MRSA cases. Four publications reported a worse functional or microbiological outcome in MRSA, compared to non-MRSA, cases, but the findings were variable and differences did not seem to be significant. Many trials failed to adjust for case-mix or to definitively demonstrate a relationship between microbiology and outcomes. Few of the articles specifically commented on whether the MRSA isolates were health care- or community-acquired strains. Notwithstanding the substantial limitations of the available literature, there does not appear to be a need for any special treatment for DFI caused by MRSA. The current guidelines for treating according to established international recommendations seem appropriate.

Wonder of Life (kalanchoe pinnata) leaves to treat diabetic foot infections in Trinidad & Tobago: a case control study

: Wonder of Life (kalanchoe pinnata) leaves are commonly used to treat diabetic foot infections. These patients are usually non-compliant with conventional medical therapy. We surmised that these patients would have a higher incidence of treatment failures. Patients admitted with diabetic foot infections were separated into two groups: a Study Group comprised patients who used topical kalanchoe pinnata and a Medical Therapy Group contained patients who were compliant with conventional treatment. The patients were observed over the course of their hospitalisation.

RESULTS

There were 382 patients in the Medical Therapy Group and 96 in the Study Group, who waited 9.21 ± 5.3 days (Mean ± SD) before seeking medical attention. There were similar rates of all amputations (34.8% vs. 37.5%; P = 0.643) and mortality (0.8% vs. 1.0%; P = 1.000) in the Study and Medical Therapy groups.

CONCLUSIONS

There may be value in the use of topical kalanchoe pinnata to treat diabetic foot infections.

Solid pseudopapillary neoplasms of the pancreas: a report of two cases

Solid pseudopapillary neoplasms of the pancreas are uncommon, accounting for only 1-2% of all pancreatic neoplasms. These tumors are being detected at an increased rate, probably due to the increased awareness and the liberal use of imaging. We report two cases of patients with solid pseudopapillary pancreatic tumors and review the existing literature.

Self-directed treatment for lower limb wounds in persons with diabetes: a short report

AIM

There has been little focus on self-directed treatment for lower limb wounds, although it a common practice among persons with diabetes across the Caribbean. We sought to document this practice in a Caribbean nation.

METHODS

We prospectively interviewed all consecutive patients with diabetes who were admitted with lower limb wounds at the San Fernando General Hospital in Trinidad and Tobago over a period of 18 months. A questionnaire was used to collect data on patient demographics, use of self-directed treatment, and details of these treatments.

RESULTS

Of 839 persons with diabetes who were admitted with infected lower limb wounds, 344 (41%) admitted to self-directed treatment before seeking medical attention. These patients were predominantly male (59.9%) at a mean age of 56.4±12.4 years. The practice was most common in persons of Afro-Caribbean descent (45.9%) and those with type 2 diabetes (93.9%). In this group, 255 (74.4%) patients were previously admitted to hospital for lower limb infections. And of those, 32 (12.6%) had a prior amputation and 108 (42.4%) had at least one operative debridement specifically for foot infections.

CONCLUSION

Caribbean cultural practices may be an important contributor to negative outcomes when treating lower limb wounds in persons with diabetes. Despite being acutely aware of the potentially devastating consequences of inadequate treatment, 41% of our patients with diabetes still opted to use self-directed treatment for lower limb wounds. This deserves further study in order to give a more tailored approach in care delivery.