Deep Tissue Samples Research Articles

A geographical paradox: microbiological profile and antibiotic resistance of diabetic foot infection in North West England

AbstractBackground: The microbiological composition of diabetic foot infection (DFI) and its antimicrobial resistance exhibit variations in different parts of the world.Aims: This study aimed to shed light on the microbial load associated with DFI and the patterns of antibiotic resistance in Northwest England.Methods: This was a retrospective descriptive study that included 67 patients (55 male [78.6%]). The mean age at diagnosis was 45.6 years (standard deviation, 15.8). The culture of deep tissue samples was analysed together with antibiotic resistance.Results: A total of 114 causative pathogens were identified. Of note, 40 patients (60.00%) had polymicrobial infections. Moreover, 58.77% of the microbial cohort was composed of gram‐positive bacteria. Staphylococcus spp. were found in 32 patients (47.76%) and were the most prevalent pathogen in our cohort. Anaerobic bacteria were found in 17 patients (25.37%) and were the second most common pathogen in our cohort. Corynebacterium spp., Streptococcus spp. and Enterococcus spp. were identified in 11 (16.42%), 10 (14.93%) and 9 (13.43%) patients, respectively. Among the gram‐negative bacteria, Escherichia spp. were found in 7 patients (10.45%), Enterobacter spp. were found in 6 patients (8.96%), Klebsiella spp. were found in 4 patients (5.97%), Proteus spp. were found in 4 patients (5.97%) and Alcaligenes spp. were found in 2 patients (2.99%). The remaining less common organisms collectively accounted for 1.49% prevalence. Regarding antibiotic therapy, the highest resistance was observed for ciprofloxacin (12 [17.91%]), followed by amoxicillin (11 [16.42%]), penicillin (10 [14.93%]), clarithromycin (7 [10.45%]), trimethoprim (7 [10.45%]), doxycycline (6 [8.96%]) and piperacillin/tazobactam (5 [7.46%]).Conclusions: In contrast to the predominant aerobic gram‐negative bacteria in Asia, the Middle East and Africa, our study found a paradoxically higher prevalence of gram‐positive and anaerobic bacteria in North West England. Moreover, our study found a high incidence of resistance to ciprofloxacin and amoxicillin.

16S rRNA sequencing reveals microbiota differences in orthopedic implants between aseptic loosening and prosthetic joint infection cases.

Prosthetic joint infection (PJI) and aseptic loosening (AL) are common complications of total joint arthroplasty. An accumulation of evidence indicates the presence of microbial communities on prosthetic implants, but the overall microbial profile is unclear. In this study, we aimed to investigate the differences in the microbial composition of prosthetic implants obtained from PJI and AL patients using the 16S rRNA sequencing method. Patients who underwent revision hip, knee, or shoulder arthroplasty caused by PJI (n = 20) or AL (n = 10) were enrolled in the study. 16S rRNA sequencing targeting the V3-V4 region was performed on the microbial specimens collected from synovial fluid, periprosthetic deep-tissue, and biofilm during the revision surgery. The sequenced raw data were analysed for microbial composition and ecological and differential abundance analyses using bioinformatics tools. The AL group had relatively balanced and higher diversity, with Staphylococcus, Streptococcus, and Veillonella being prominent. In the PJI group, Staphylococcus and Pseudomonas were predominant, especially in deep-tissue samples and biofilm samples, respectively. The differential abundance analysis identified 15 and 2 distinctive taxa in the AL and PJI groups, respectively. Our findings provided preliminary insights supporting the existence of periprosthetic microbiota in orthopedic implants and explaining the differences in microbial composition between the AL and PJI groups.

Antibiotic Stewardship in the Management of Infected Diabetic Foot Ulcer Disease in Less Developed Countries.

Diabetic foot ulcers in developing countries often become infected. The healthcare systems are often not equipped to conduct the culture and the sensitivity tests required for prescribing a targeted antibiotic treatment for diabetic foot infection (DFI). We evaluate antibiotic stewardship programmes for DFIs, at every level of health care, with an emphasis on resource-poor settings such as in Africa. The management of DFI very often is adapted to the financial and practical realities of the resource-poor regions. The application of the point-of-care Gram stain of deep tissue samples is efficient, rapid, low cost and ubiquitously available. Upon the identification of the predominant pathogen in the Gram stain, a semi-quantitative preemptive antibiotic treatment can be started in accordance with the World Health Organization Aware, Watch and Restrict Essential Medicine List. This list is catered to every country and is a powerful tool. However, some basic knowledge of the local microbiological epidemiology is necessary to choose the most appropriate agent. We report our experience on using the rapidly available Gram stain for narrowing the preemptive choice of listed antibiotic agents, as an economic tool for antibiotic stewardship in DFIs. In the practical and resource-saving management of DFI, the 'therapeutic' use of Gram stains is not common in resource-rich countries but should be added to the arsenal of the general efforts for antibiotic stewardship.

USE OF TAQMAN ARRAY TO INVESTIGATE INFECTION IN DIABETIC FOOT WOUNDS

IntroductionDiabetic foot disease is a major public health problem with an annual NHS expenditure in excess of £1 billion. Infection increases risk of major amputation fivefold. Due to the polymicrobial nature of diabetic foot infections, it is often difficult to isolate the correct organism with conventional culture techniques, to deliver appropriate narrow spectrum antibiotics. Rapid DNA-based technology using multi-channel arrays presents a quicker alternative and has previously been used effectively in intensive care and respiratory medicine.MethodsWe gained institutional and Local Ethics Committee approval for a prospective cohort study of patients with clinically infected diabetic foot wounds. They all had deep tissue samples taken in clinic processed with conventional culture and real-time PCR TaqMan array.Results50 samples were taken from 39 patients between October 2020 and March 2022. 84% of patient were male, 88% had type 2 diabetes. The ulcers were of variable chronicity prior to sampling (range 1–113 weeks) and mean HbA1c was 67.2mmol/mol. Ulcers were on the heel (3), midfoot (6) and forefoot (41). Minimum follow up was 3 months. 6 ulcers healed, 24 patients were admitted due to foot disease, there were 2 major amputations and 4 deaths. TaqMan array results were available a mean of 4.3 days earlier than culture results. 9 patients had negative conventional cultures and 8 were negative onarray testing. 17 patients had the same organisms detected on culture and array. 16 of these 17 had additional organisms detected by array. The most frequent organisms detected on array that were not detected by culture were Staphylococcus spp., Enterobacter, Pseudomonas and fungi.ConclusionTaqMan array shows promise in detecting infecting organisms from diabetic foot wounds and providing earlier results than standard culture, which may enable appropriate and timely antibiotic therapy.

Role of surgery along with antimicrobials in refractory skull base osteomyelitis-A prospective observational study.

Study aimed to ole of surgery along with antimicrobials to improve clinical outcomes in treating refractory cases of skull base osteomyelitis (SBO). A prospective observational study in a tertiary care centre with 70 SBO patients meeting eligibility criteria. The study population comprised 35 patients refractory to systemic antimicrobials of at least 4 weeks duration who later underwent surgery in addition to medication (surgical group). They were compared with a medical group that responded to medications alone. The outcome variables studied were the resolution of clinical features (pain, discharge, radiology, and inflammatory markers), culture yield, and total duration of treatment. According to our study, relief of pain was faster in the surgical group (1.66 against 4.57 months) with statistical significance (p < 0.001). Relief of symptoms (p < 0.001), radiological improvement (p = 0.001), and normalising of inflammatory markers (p < 0.001) were better in the surgical group than in the medical group. The duration of treatment was an average of 9.2 months in the surgical group compared to 11.3 months in the medical group (p = 0.019). Microbial culture from deep tissue sampling was positive in 24 surgical patients (68.57%). The treatment response in selected patients of refractory SBO who underwent surgery along with antimicrobials was better than the group who responded to antimicrobials alone. Surgery provided higher microbial yield resulting in culture-specific antimicrobials. The surgical group observed faster relief of symptoms, reduced hospital stay, and total treatment duration.

Clinical impact of fungal colonization of burn wounds in patients hospitalized in the intensive care unit: a retrospective cohort study

BackgroundInvasive fungal infections in burn victims significantly increase mortality and hospitalization. The effect of fungal burn wound colonization has not been established.MethodsAll adult patients hospitalized in the intensive care unit...

Antimicrobial resistance in surgical infections: experience from open tibia fracture-related infection intraoperative tissue specimens

Background Antimicrobial resistance in surgical infections is known to have significant morbidity and mortality in extreme cases on top of increased costs in medical expenditure. This study aimed to analyze antimicrobial resistance patterns of microbes in open tibia fracture-related infection (FRI) using intraoperative tissue samples. Methods Between January and June 2022, a descriptive cross-sectional observational study was conducted involving patients aged 18 and above with open tibial shaft fractures. Microbiological culture and sensitivity of three intraoperative deep tissue and bone samples taken by sterile techniques using separate instruments in patients with infection. Antimicrobial susceptibility testing was performed using the Kirby-Bauer disk diffusion method along with biomechanical tests for microbial identification. Results Fifty-seven deep tissue samples were taken from 19 patients with FRI who underwent surgery during the study period were analyzed. Almost all (96.5%) intraoperative tissue samples were culture-positive identifying 73 bacterial isolates out of which 57.9% were polymicrobial. The most frequent isolated bacteria were Gram-negative bacteria 56 (76.7%) with a predominance of Proteus spp 13 (17.8%). Methicilin Resistance Staphyaureus comprised 12 (16.4%) of the isolates whereas Inducible Clindamycin resistance was identified in 8 (57.1%) of Staphyloccus aureus isolates. More than half of the isolates 30 (53.6%) comprised of Extended Spectrum Beta Lactamase producing bacteria. There was high resistance to Cephalosporins and Amoxyclavulanic acid as the efficacy was low ranging from 28.2, 27.8, and 30.0% for cefotaxime, ceftazidime and amoxicillin/clavulanic acid, respectively. Almost all Gram-negative bacteria 47 (83.9%) had multidrug resistance pattern except for Pseudomonas aureginosa that had 77.8 to 88.9% susceptibility to all tested antibiotics. Conclusion High resistance to cephalosporins in patients with delayed or late infection in open tibia FRI is alarming and further studies to establish causes are indicated.

The Microbiological Profile and Antibiotic Susceptibility of Fracture Related Infections in a Low Resource Setting Differ from High Resource Settings: A Cohort Study from Cameroon.

Fracture-related infection (FRI) is a common and devastating complication of orthopedic trauma in all settings. Data on the microbiological profile and susceptibility of FRI to antibiotics in low-income countries are scarce. Therefore, this study aimed to investigate the microbial patterns and antimicrobial susceptibility of FRI in a sub-Saharan African setting in order to provide guidance for the formulation of evidence-based empirical antimicrobial regimens. We conducted a retrospective analysis of patients treated for FRI with deep tissue sampling for microbiological culture from January 2016 to August 2023 in four tertiary-level hospitals in Yaoundé, Cameroon. There were 246 infection episodes in 217 patients. Cultures were positive in 209 (84.9%) cases and polymicrobial in 109 (44.3%) cases. A total of 363 microorganisms from 71 different species were identified, of which 239 (65.8%) were Gram-negative. The most commonly isolated pathogens were Staphylococcus aureus (n = 69; 19%), Enterobacter cloacae (n = 43; 11.8%), Klebsiella pneumoniae (n = 35; 9.6%), Escherichia coli (n = 35; 9.6%), and Pseudomonas aeruginosa (n = 27; 7.4%). Coagulase-negative staphylococci (CoNS) were isolated in only 21 (5.9%) cases. Gram-negative bacteria accounted for the majority of the infections in early (70.9%) and delayed (73.2%) FRI, but Gram-positive bacteria were prevalent in late FRI (51.7%) (p < 0.001). Polymicrobial infections were more frequent in the early (55.9%) and delayed (41.9%) groups than in the late group (27.6%) (p < 0.001). Apart from Staphylococcus aureus, there was no significant difference in the proportions of causative pathogens between early, delayed, and late FRI. This study found striking resistance rates of bacteria to commonly used antibiotics. MRSA accounted for 63% of cases. The most effective antibiotics for all Gram-positive bacteria were linezolid (96.4%), vancomycin (92.5%), clindamycin (85.3%), and fucidic acid (89.4%). For Gram-negative bacteria, only three antibiotics displayed a sensitivity >50%: amikacin (80.4%), imipenem (74.4%), and piperacillin + tazobactam (57%). The most effective empirical antibiotic therapy (with local availability) was the combination of vancomycin and amikacin or vancomycin and imipenem. In contrast to the literature from high-resource settings, this study revealed that in a sub-Saharan African context, Gram-negative bacteria are the most common causative microorganisms of FRI. This study revealed striking resistance rates to commonly used antibiotics, which will require urgent action to prevent antimicrobial resistance in low and middle-income countries.

Isothermal microcalorimetry improves accuracy and time to bacterial detection of periprosthetic joint infection after total joint arthroplasty.

Isothermal microcalorimetry (IMC) was evaluated compared to conventional cultures to determine the clinical performance for diagnosing periprosthetic joint infection (PJI) of hip/knee replacements. We prospectively collected three to five deep tissue samples per patient from 152 patients undergoing conversion or revision hip/knee arthroplasty from July 2020 to November 2022. Cultures and IMC for each sample were compared for concordance, median time to detection (TTD), and diagnostic performance based on 2013 Musculoskeletal Infection Society criteria. Secondary analyses involved patients on antibiotics at sampling. The 152 total patients had 592 tissue samples (mean 3.9 ± 0.3) with sample concordance between cultures and IMC of 90%. IMC demonstrated a sensitivity of 83%, specificity of 100%, negative predictive value (NPV) of 89%, and positive predictive value (PPV) of 100% for PJI. Cultures resulted in 69% sensitivity, 100% specificity, 81% NPV, and 100% PPV. The accuracy of IMC was 93% compared to 87% for cultures (P < 0.001). The median TTD of PJI by cultures was 51 (21-410) hours compared to 10 (0.5-148) hours for IMC (P < 0.001). For 39 patients on chronic antibiotics, sensitivity in PJI detection was 93%, specificity 100%, NPV 85%, and PPV 100% by IMC compared to 79% sensitivity, 100% specificity, 65% NPV, and 100% PPV for cultures. The accuracy was 95% for IMC compared to 85% for cultures (P < 0.001) with median TTD of 12 (0.5-127) hours compared to 52 (21-174) hours (P < 0.001). Utilizing IMC for PJI detection improves TTD by nearly 2 days while improving diagnostic accuracy compared to cultures, particularly in patients on chronic antibiotics.

Phenotypic and Genotypic Characterization of Cutibacterium acnes Isolated from Shoulder Surgery Reveals Insights into Genetic Diversity.

Specific virulence factors that likely influence C. acnes invasion into deep tissues remain to be elucidated. Herein, we describe the frequency of C. acnes identification in deep tissue specimens of patients undergoing clean shoulder surgery and assess its phenotypic and genetic traits associated with virulence and antibiotic resistance patterns, compared with isolates from the skin of healthy volunteers. Multiple deep tissue specimens from the bone fragments, tendons, and bursa of 84 otherwise healthy patients undergoing primary clean-open and arthroscopic shoulder surgeries were aseptically collected. The overall yield of tissue sample cultures was 21.5% (55/255), with 11.8% (30/255) identified as C. acnes in 27.3% (23/84) of patients. Antibiotic resistance rates were low, with most strains expressing susceptibility to first-line antibiotics, while a few were resistant to penicillin and rifampicin. Phylotypes IB (73.3%) and II (23.3%) were predominant in deep tissue samples. Genomic analysis demonstrated differences in the pangenome of the isolates from the same clade. Even though strains displayed a range of pathogenic markers, such as biofilm formation, patients did not evolve to infection during the 1-year follow-up. This suggests that the presence of polyclonal C. acnes in multiple deep tissue samples does not necessarily indicate infection.

Detection of Cutibacterium (Propionibacterium) acnes in orthopaedic surgery: serious problem or contamination?

PurposeBone and joint infections are an important and increasing problem. Whether intraoperatively detected bacteria should be considered relevant or not is often difficult to assess.This retrospective cohort study analyzes the relevance of C. acnes cultured from deep intraoperative specimens.MethodsAll deep tissue samples collected intraoperatively between 2015 and 2020 from a quartiary care provider were evaluated for detection of C. acnes and its therapeutical consequences. Infection rates were determined according to a standardized definition and protocol and analyzed in dependence of patient’s demographic data (age and gender), operative parameters (type of surgery, body region/location of surgery, and impression of the surgeon), and initiated therapy.ResultsIn 270 cases of more than 8500 samples, C. acnes was detected. In 30%, the detection was considered an infection. The number of samples taken and tested positive for C. acnes correlated significantly with its classification as a cause of infection. If more than one sample of the patient was positive, the detection was significantly more likely to be treated as infection (p < 0.001).In 76% of cases, a consultation to the infectious diseases (ID) department took place regarding the classification of the pathogen detection and the therapy to be carried out.Almost all of the tested isolates demonstrated the wild-type susceptibility for penicillin and clindamycin.ConclusionIntraoperative detection of skin-colonizing bacteria such as C. acnes is not always synonymous with infection. In particular, if other examination results contradict an infection (pathological sample without evidence of an infectious event, detection of malignant cells, etc.), the situation must be considered in a very differentiated manner. Interdisciplinary boards, for example, are suitable for this purpose. Care should be taken to obtain a sufficiently large number of tissue samples for microbiological examination to be able to better classify the result.

Factors Associated With the Development of a Confirmed Fracture-Related Infection.

To identify factors associated with the development of fracture-related infection (FRI) in patients who have undergone operative fixation of their fracture. Retrospective study. Academic medical center. Patients with peripheral extremity long-bone fractures and shoulder and pelvic girdle fractures who underwent operative repair. This included patients who had undergone fixation inside and outside of our institution. Chi-square, Fisher exact testing, analysis of variance (ANOVA), and t tests were used for analysis of data, as appropriate. Binomial logistic regression analysis was performed to determine risk factors of FRI. Demographics, fracture location, injury mechanism, open wound status, and wound complication type. One hundred ninety-three patients comprised the FRI cohort. Of those with confirmed signs of FRI, 36 (18.7%) had wound breakdown to bone or implant, 120 (62.1%) had a sinus track, and 170 patients (88.1%) had the confirmed presence of microorganisms in deep tissue samples obtained during operative intervention. Factors associated with development of an FRI were as follows: higher BMI; being of Black and Hispanic race; higher American Society of Anesthesiologists class; history of tobacco, alcohol, and drug use; and fractures of the lower extremity (foot, tibia, and femur/pelvis). The results of binary logistic regression demonstrated that treatment at an urban level I trauma center and drug use positively predicted the development of FRI. Our results demonstrate that higher BMI; being of Black or Hispanic race; higher American Society of Anesthesiologists; history of tobacco, alcohol, and drug use; and fractures of the foot, tibia, and femur/pelvis are all factors associated with development of FRI. Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Detection of Cutibacterium acnes in Tissue Samples from Clean Primary Shoulder Surgeries - Part II.

Objective Research and identification of Cutibacterium acnes ( C. acnes ) and other microorganisms in deep tissue samples collected in clean shoulder surgeries of patients who did not undergo any previous invasive joint procedure and who had no clinical history of infection. Methods We analyzed the results of cultures of intraoperative deep tissue samples from 84 patients submitted to primary clean shoulder surgery. Tubes containing culture medium were used for storage and transport of anaerobic agents, prolonged incubation time, and mass spectrometer for diagnosis of bacterial agents. Results Bacteria growth was evidenced in 34 patients (40.4%) of the 84 included in the study. Of these, 23 had growth of C. acnes in at least one sample of deep tissue collected, corresponding to 27.3% of the total patients. The second most common agent was Staphylococcus epidermidis , present in 7.2% of the total individuals included. We showed a higher relationship between sample positivity and males, a lower mean age, absence of diabetes mellitus, ASA I score, and antibiotic prophylaxis in anesthetic induction with cefuroxime. Conclusions A high percentage of isolates of different bacteria was found in shoulder tissue samples of patients undergoing clean and primary surgeries, who had no history of previous infection. Identification of C. acnes was high (27.6%), and Staphylococcus epidermidis was the second most frequent agent (7.2%).

Comparison of Microbiological Results of Superficial Swab versus Deep Tissue Biopsy in Diabetic Foot Infections: A Prospective Observational Study from North India

Introduction: Diabetes mellitus is the leading cause of nontraumatic lower extremity amputation worldwide. Risk of developing a foot ulcer in diabetic patients has increased to 12-25% during their lifetime. Inappropriate sampling technique leading to contaminated samples is a well-known threat among patients of diabetic foot. In this study we compared two microbiological sampling techniques, superficial swabbing and deep tissue biopsy for identification of pathogens. Material and Methods: It was a prospective observational cross-sectional study. Diabetic foot was defined as per standard guidelines. Careful and meticulous examination of diabetic foot ulcer was done. Two specimens were collected from each wound. The first specimen was a wound swab collected by using Levine technique; another was taken via punch biopsy from the ulcer base. It was a deep tissue sample of 4 mm size. Results: A total of 120 diabetic patients with diabetic foot infection were included in this study. In swab culture 80.83% patients had mono microbial growth, 15% had polymicrobial and 4.10% had no growth. In deep tissue culture 87.50% had mono microbial growth, 2.50% had poly microbial and 10% were sterile. Staphylococcus aureus was most common isolate followed by E. coli. It was observed that though monomicrobial growth was most common in both the types of samples but was higher in deep tissue biopsy than in superficial swab samples. Conclusion: The isolation of microorganism via deep tissue sampling in diabetic foot ulcer patients is more reliable compared to superficial swab samples and a better guide to antibiotic therapy.

A Study on Prevalence, Profile, and Risk Factors of Developing Fungal Infection in Patients With Diabetic Foot Ulcer

Background: Many chronic nonhealing diabetic foot ulcers (DFUs) with increased rates of amputation are frequently associated with fungal infections. Purpose: To evaluate the prevalence, profile, and risk factors of developing a fungal infection in patients with DFU. Methods: This prospective observational study was carried out from October 2018 to July 2020. All adult patients with DFUs admitted to the surgery ward were recruited. Patients on antifungal therapy or who received such therapy within 6 weeks prior to admission were excluded. Three deep tissue samples were sent for bacterial culture, fungal culture, and histopathological examination of fungal elements. Results: A total of 251 patients were enrolled in the study. Of the 23.3% of patients with positive fungal growth (n = 47/202), 2% (n = 4/202) had pure fungal growth and 21.3% (n = 43/202) had mixed growth with bacteria in their ulcers (ie, non-contaminated samples). A significant association was found between wound grade (P = .027), ulcer duration (P = .028), and positive fungal growth in DFUs. Conclusions: In this study, the prevalence of fungal infection in DFUs was 23.3%; Candida tropicalis (27.08%) was the most common isolate, followed by C. albicans (20.83%). The rate of fungal infections was high in patients with mild diabetic foot infection or DFU of 7 to 14 days’ duration.

Pre-Referral Microbiology in Long Bone Infection: What Can It Tell Us?

Background: It remains unclear how accurately patients' previous microbiology correlates with that ascertained from deep sampling in long bone infection. This study assessed the quality of microbiology referral information and compared it to the gold standard of intra-operative deep tissue sampling. Methods: All patients referred to a single specialist centre within the UK between January 2019 and March 2020 who received surgery for long bone infection were eligible for inclusion. Data on microbiological testing that was performed prior to referral was collected prospectively at the time of clinic appointment and prior to surgery. Pre-referral microbiology was compared to microbiology from deep tissue samples taken during surgery. Results: 141 patients met the diagnostic criteria for long bone infection and were included for analysis. Of these, 72 patients had microbiological information available at referral from 88 samples, obtained from either sinus swab (n = 40), previous surgical sampling (n = 25), biopsy (n = 19) or blood cultures (n = 4). In 65.9% of samples, pre-referral microbiology was deemed to be a non-match when compared to intra-operative samples. Factors that increased risk of a non-match included presence of a sinus (odd's ratio (OR) 11.3 [95% CI 2.84-56.6], p = 0.001), increased duration of time from sampling (OR 2.29, [95% CI 1.23-5.90], p = 0.030) and results from prior surgical sampling (OR 23.0 [95% CI 2.80-525.6], p = 0.011). Furthermore, previous surgical debridement gave an increased risk of multi-, extensively or pan-resistant isolates cultured from intra-operative sampling (OR 3.6 [95% CI 1.5-8.7], p &lt; 0.01). Conclusions: We have demonstrated that presence of a sinus, a long time from the sample being taken and results from prior surgical sampling are more likely to give inaccurate representation of current microbiology. Importantly, in cases with previous debridement surgery, there was an increased risk of multi drug resistant isolates which should be planned for in future treatments.

Aetiology of long bone chronic osteomyelitis: an analysis of the current situation in one region in Egypt

IntroductionChronic osteomyelitis (COM) is a devastating infection requiring a multidisciplinary approach, including radiology, microbiology, pathology, and orthopaedic surgery to treat. The present study analysed the bacterial profile causing chronic osteomyelitis and their antibiogram in our region.Patients and methodsThis prospective study was done on a consecutive group of patients who underwent surgical debridement for long bone COM. Three to six deep tissue samples were collected during the index debridement for microbiology and one sample for histopathology. Antimicrobial sensitivity testing used an automated bacterial identification system. Gram stain was used to identify the bacteria type from its size, shape, and arrangement of bacterial growth.ResultsIntra-operative deep tissue and bone specimens accurately identified causative bacteria in 84.8% of patients. Gram-ve bacilli (GNB) were the most common causative organisms in 51.6% of all growing samples (36.4% isolated G-ve and 15.2% mixed with G + ve). Thirty-three patients (30 males/three females) were included; the mean age at index debridement surgery was 37.1 years. Half of the cohort had no metalwork. The aetiology of COM was post-operative infection in half of the patients.ConclusionThere may be concerning features in our patients’ aetiologies and causative organisms; closed fractures turn into COM postoperatively, several unsuccessful attempts, delayed index debridement, and more GNB. Plans need to be applied to break the cycle and improve outcomes.

P288 Rhinocerebral mucormycosis due to Saksenaea vasiformis in a Sri Lankan patient: A rare fungal infection

Poster session 2, September 22, 2022, 12:30 PM - 1:30 PMBackground: Rhizopus, Rhizomucor, and Mucor species are renowned agents causing rhinocerebral mucormycosis; a disease with a high mortality rate. Saksenaea vasiformis is extremely rarely observed in this clinical entity. Minimal sporulation in common laboratory media might be responsible for the under-reporting of this organism. Here we present an uncommon case of rhinocerebral mucormycosis due to S. vasiformis. in a Sri Lankan patient with diabetes mellitus.Case History: A 66-year-old female with diabetes mellitus was admitted with frontal headache, right-sided nasal block, anosmia, and right-side facial swelling. Examination revealed facial edema, maxillary sinus tenderness, and a white patch over the hard palate. Thick pus in postnasal space, growth in posterior tongue base, inflamed palate, and oropharynx, were revealed by rigid nasal endoscopy. She developed ophthalmoplegia along with right V and XII cranial nerve palsies irrespective of antibacterial therapy. Right side pansinusitis was observed in non-contrast computed tomography. She was subjected to right-side full house functional endoscopic sinus surgery with right orbital and optic nerve decompression. Irregular wide, ribbon-like, non-septate hyphae suggestive of Zygomycete fungi were observed in the direct microscopy of a deep surgical tissue sample and started with intravenous amphotericin B. After 5 days of incubation, the culture grew a zygomycetes-like mold with a lack of sporulation on Sabouraud dextrose agar, potato dextrose agar, and slide culture. However, the floating agar technique succeeded in producing flasks-shaped sporangium on a short sporangiophore with brown pigmented rhizoids after 14 days of incubation. The phenotypic features were suggestive of S. vasiformis. She was subjected to repeated debridement surgeries and treatment with amphotericin B was continued. She was clinically improving however, refractory hypokalemia along with hypernatremia interrupted her antifungal therapy resulting return of severe symptoms. Contrast-enhanced computed tomography of the brain revealed multiple micro-abscesses in the right temporal lobe. She clinically deteriorated and succumbed to the illness.Discussion: Saksenaea vasiformis, a member of Mucorales, is largely bounded to cutaneous and subcutaneous infections. Rhino-orbital-cerebral infection is relatively uncommon and most of the reported cases were fatal irrespective of optimal therapy. Prompt diagnosis through fungal investigations of deep biopsy is mandatory. The delayed identification of this organism is attributed to its nature of poor sporulation on routine media. Special culture techniques and nutritionally deprived media enhance sporulation. Saksenaea vasiformis is usually sensitive to amphotericin B, high minimum inhibitory concentration has been reported though.ConclusionSpecific culture techniques should be used to induce sporulation if non-sporulating mucormycetes are encountered. Rhinocerebral mucormycosis is associated with a high degree of mortality even with effective antifungal therapy.

Mid- to long-term results of single-stage surgery for patients with chronic osteomyelitis using a bioabsorbable gentamicin-loaded ceramic carrier.

Excision of chronic osteomyelitic bone creates a dead space which must be managed to avoid early recurrence of infection. Systemic antibiotics cannot penetrate this space in high concentrations, so local treatment has become an attractive adjunct to surgery. The aim of this study was to present the mid- to long-term results of local treatment with gentamicin in a bioabsorbable ceramic carrier. A prospective series of 100 patients with Cierny-Mader Types III and IV chronic ostemyelitis, affecting 105 bones, were treated with a single-stage procedure including debridement, deep tissue sampling, local and systemic antibiotics, stabilization, and immediate skin closure. Chronic osteomyelitis was confirmed using strict diagnostic criteria. The mean follow-up was 6.05 years (4.2 to 8.4). At final follow-up, six patients (six bones) had recurrent infection; thus 94% were infection-free. Three infections recurred in the first year, two in the second year, and one 4.5 years postoperatively. Recurrence was not significantly related to the physiological class of the patient (1/20 Class A (5%) vs 5/80 Class B (6.25%); p = 0.833), nor was it significantly related to the aetiology of the infection, the organisms which were cultured or the presence of nonunion before surgery (1/10 with nonunion (10%) vs 5/90 without nonunion (5.6%); p = 0.570). Organisms with intermediate or high-grade resistance to gentamicin were significantly more likely in polymicrobial infections (9/21; 42.8%) compared with monobacterial osteomyelitis (7/79 (8.9%); p < 0.001). However, recurrence was not significantly more frequent when a resistant organism was present (1/16 for resistant cases (6.25%) vs 5/84 in those with a microbiologically sensitive infection (5.95%); p = 0.958). We found that a single-stage protocol, including the use of a high-delivery local antibiotic ceramic carrier, was effective over a period of several years. The method can be used in a wide range of patients, including those with significant comorbidities and an infected nonunion.Cite this article: Bone Joint J2022;104-B(9):1095-1100.

CERRAHİ DEBRİDMAN İHTİYACI OLAN DİYABETİK AYAKLI HASTALARDA ANTİBİYOTİK DİRENÇ DURUMU

OBJECTIVE: The main purpose of this study is to evaluate the relationship between microorganisms and antibiotic resistance or susceptibility in samples obtained from patients with wound debridement due to diabetic foot.MATERIAL AND METHODS: In this retrospective study patients who underwent debridement for the diabetic foot in two separate referral centers between 2013 and 2018 were evaluated. Demographic data of patients including age, gender were collected. The microorganism and antibiogram results isolated from deep tissue samples taken from diabetic foot wounds were recorded.RESULTS: 84 patients (47 male, 37 female) who underwent debridement surgery due to diabetic foot were included in the study. Their ages ranged from 26 to 87 years and the mean age was 63.2 ± 16 years. Bacterial growth (29 gram-positive and 15 gram-negative) was detected in 44 (53%) samples. The most isolated microorganisms were Staphylococcus aureus and Escherichia coli, respectively. Only one of the staphylococci isolated in the cultures was methicillin resistant one of the Escherichia coli was extended-spectrum beta-lactamase (ESBL) (+).CONCLUSIONS: Bacteria isolated in diabetic foot infection have gram (-) and gram (+) characteristics, and this should be taken into consideration when planning the treatment.