Clindamycin is a lincosamide antibiotic that has been used as a topical, oral, or injectable formulation for over five decades. It exhibits a narrow spectrum of microbiologic activity, primarily against gram-positive and anaerobic bacteria. In dermatology, clindamycin has been used primarily as a topical agent, usually for the treatment of acne vulgaris. Despite questions surrounding antibiotic resistance and/or its relative contribution to antibiotic treatment efficacy, a large body of data support the therapeutic value of topical clindamycin for acne vulgaris. As a systemic agent, clindamycin is used orally to treat a variety of cutaneous bacterial infections, and sometimes for acne vulgaris, with oral treatment for the latter less common in more recent years. The modes of action of clindamycin are supported by data showing both its anti-inflammatory and antibiotic mechanisms, which are discussed here along with pharmacokinetic profiles and structure-activity relationships. The diverse applications of clindamycin for multiple disease states, its efficacy, and safety considerations are also reviewed here, including for both topical and systemic formulations. Emphasis is placed on uses in dermatology, but other information on clindamycin relevant to clinicians is also discussed.

Objective: We evaluated the impact of a methicillin-resistant Staphylococcus aureus (MRSA) nasal polymerase chain reaction (PCR) protocol on the vancomycin length of therapy (LOT) for skin and soft tissue infections (SSTIs). Design: Retrospective quasi-experimental pre- and post- MRSA nasal PCR protocol implementation study. Setting: Tertiary-care academic medical center in Jacksonville, Florida. Patients: Eligible patients received empiric vancomycin for SSTIs from January 1st to September 30th 2020 (pre-implementation group) and from January 1st to September 30th 2022 (post-implementation group). Intervention: The electronic health system software was modified to provide a best-practice advisory (BPA) prompt to the pharmacist upon order verification of vancomycin for patients with SSTIs. Methods: We reviewed patient records to determine the time from vancomycin prescription to de-escalation. The secondary outcomes were incidence of acute kidney injury (AKI), number of vancomycin levels collected, and hospital length of stay (LOS). Results: The study included 131 patients (pre-implementation, n = 86 and post-implementation, n = 45). There was no significant difference in vancomycin length of therapy (LOT) between implementation groups: mean LOT in days and standard deviation (SD) were 2.7 (1.9) and 2.6 (1.3), respectively, p-value 0.493. Of significance, in the post-implementation group, vancomycin LOT between patients with a negative and positive MRSA PCR were 2.3 (1.1) and 3.9 (1.6), p-value 0.006. There was no difference in secondary outcomes. Conclusion: The utilization of the MRSA nasal PCR to guide vancomycin de-escalation did not significantly change the vancomycin LOT, however in the post-implementation group there was a significant difference in vancomycin LOT between negative and positive MRSA PCRs.

Group A ß-hemolytic Streptococcus (S. pyogenes), also known as GAS, is a Gram-positive bacterium. It can be easily identified in the microbiology laboratory by its ability to hemolyse blood in culture media. This bacterium is highly virulent due to its production of enzymes and toxins, and its ability to cause immunologically mediated diseases such as rheumatic fever and post-streptococcal glomerulonephritis. GAS is the primary cause of bacterial pharyngotonsillitis, although it is typically a benign and non-invasive disease. However, it also has the potential to cause severe skin and soft tissue infections, necrotising fasciitis, bacteraemia and endocarditis, pneumonia and empyema, and streptococcal toxic shock syndrome, without any age or predisposition limits. The term invasive GAS disease (iGAS) is used to refer to this group of conditions. In more developed countries, iGAS disease has declined thanks to improved hygiene and the availability of antibiotics. For example, rheumatic fever has practically disappeared in countries such as Spain. However, recent data suggests a potential increase in some iGAS diseases, although the accuracy of this data is not consistent. Because of this, the COVID and Emerging Pathogens Committee of the Illustrious Official College of Physicians of Madrid (ICOMEM) has posed several questions about invasive GAS infection, especially its current situation in Spain. The committee has enlisted the help of several experts in the field to answer these questions. The following lines contain the answers that we have collaboratively produced, aiming to assist not only the members of ICOMEM but also anyone interested in this topic.

Carbapenem-resistant Enterobacterales (CRE) pose a significant public health concern. CRE could be carbapenamse producers or non-producers. In the Kingdom of Saudi Arabia, bla OXA-48 and bla NDM represent the majority of carbapenemase isolates. There are very limited treatment options for carbapenemase-producing CRE caused by bla NDM. Ceftazidime-avibactam plus aztreonam (CZA-ATM) or cefiderocol as monotherapy are considered the treatment of choice for these infections. Here, we report a case of a 70-year-old man presented with surgical site infection of above knee amputation stump. The cultures revealed carbapenem-resistant Klebsiella pneumoniae positive for bla NDM and bla OXA-48 resistant to CZA-ATM therapy and intermediate susceptibility to tigecycline. He was started on CZA-ATM both adjusted for renal function, and high dose tigecycline with daily wound dressing and irrigation. By day 20 of the antibiotic regimens, he had clinical and microbiological cure based on repeated wound cultures. This case identifies a rare incidence of CRE skin and soft tissue infection positive for bla NDM and bla OXA-48 resistant to CZA-ATM in a background of limited targeted options, but successfully treated with CZA-ATM and high-dose tigecycline. Such therapeutic approach might be useful in few circumstances when no other antibiotic options are available to treat extensively drug-resistant Klebsiella pneumoniae.

BACKGROUND: Skin and soft tissue infections (SSTIs) are among the most common indications for antimicrobial prescribing in hospitals. Inappropriate antimicrobial use can lead to increased morbidity, unnecessary hospital readmission and increased antimicrobial resistance. This study aims to assess the quality of antimicrobial prescribing practices in SSTI management within Australian hospitals to provide guidance for future practice.
METHODS: A retrospective analysis was conducted with data from the National Antimicrobial Prescribing Survey (NAPS). SSTI prescribing data from Hospital NAPS (2013-2022) and surgical site infection data from Surgical NAPS (2016-2022) datasets were analysed. Variables assessed included guideline compliance, appropriateness as per the structured NAPS algorithm and reasons for inappropriateness.
RESULTS: From the Hospital NAPS dataset, 40,535 antimicrobial prescriptions for SSTIs were analysed. The most common indication was cellulitis (34.1%; n=13,822), and the most prescribed antimicrobial was flucloxacillin (18.8%; n=7,638). SSTI indications had a lower rate of guideline compliance, but a higher rate of appropriateness compared to all other indications for antimicrobial prescriptions (guideline compliance 66.3%, n=21,035 vs 67.4%, n=156,285 appropriateness 75.6%, n=30,639 vs 72.7%, n=209,383). The most common reason for inappropriateness was incorrect dose or frequency (29.3%; n=2,367). From the Surgical NAPS dataset, 5,674 prescriptions for surgical site infections were analysed. 68.2% (n=3,867) were deemed appropriate. The most common reason for inappropriateness was incorrect dose or frequency (27.7%; n=350).
CONCLUSIONS: As SSTIs are a common indication for prescribing an antimicrobial in Australian hospitals, identifying effective antimicrobial stewardship strategies to optimise antimicrobial use for SSTI management is therefore recommended to improve patient outcomes.

BACKGROUND: Diabetes-related foot infections are common and represent a significant clinical challenge. There are scant data about outcomes from large cohorts. The purpose of this study was to report clinical outcomes from a large cohort of people with diabetes-related foot infections.
METHODS: A tertiary referral hospital limb preservation service database was established in 2018, and all new episodes of foot infections were captured prospectively using an electronic database (REDCap). People with foot infections between January 2018 and May 2023, for whom complete data were available on infection episodes, were included. Infection outcomes were compared between skin and soft tissue infections (SST-DFI) and osteomyelitis (OM) using chi-square tests.
RESULTS: Data extraction identified 647 complete DFI episodes in 397 patients. The data set was divided into two cohorts identifying each infection episode and its severity as either SST-DFI (N = 326, 50%) or OM (N = 321, 50%). Most infection presentations were classified as being moderate (PEDIS 3 = 327, 51%), with 36% mild (PEDIS 2 = 239) and 13% severe (PEDIS 4 = 81). Infection resolution occurred in 69% (n = 449) of episodes with failure in 31% (n = 198). Infection failures were more common with OM than SST-DFI (OM = 140, 71% vs. SST-DFI = 58, 29%, p < 0.00001). In patients with SST-DFI a greater number of infection failures were observed in the presence of peripheral arterial disease (PAD) compared to the patients without PAD (failure occurred in 30% (31/103) of episodes with PAD and 12% (27/223) of episodes without PAD; p < 0.001). In contrast, the number of observed infection failures in OM episodes were similar in patients with and without PAD (failure occurred in 45% (57/128) of episodes with PAD and 55% (83/193) of episodes without PAD; p = 0.78).
CONCLUSIONS: This study provides important epidemiological data on the risk of poor outcomes for DFI and factors associated with poor outcomes in an Australian setting. It highlights the association of PAD and treatment failure, reinforcing the need for early intervention to improve PAD in patients with DFI. Future randomised trials should assess the benefits of revascularisation and surgery in people with DFI and particularly those with OM where outcomes are worse.

UNASSIGNED: Fournier\'s gangrene represents a life-threatening necrotising infection affecting the perineal region, while hidradenitis suppurativa is characterised by a chronic inflammatory skin condition. The simultaneous occurrence of both conditions is exceedingly rare.
UNASSIGNED: A 42-year-old female with a documented history of severe untreated hidradenitis suppurativa presented for shortness of breath, fever and lethargy, along with extensive wounds and skin breakdown involving the left axilla, perineum, lower back, lumbosacral region and bilateral gluteal areas, extending to the perineum. Upon presentation, the patient was in a state of septic shock, and a diagnosis of actively manifesting Fournier\'s gangrene was established at the site of the pre-existing hidradenitis suppurativa lesions. Despite the implementation of an aggressive multidisciplinary approach incorporating surgical interventions, antibiotic therapy and intensive care measures, the patient\'s condition deteriorated, culminating in septic shock, multi-organ failure and eventual demise. In this report, we discuss both clinical entities, their similarities and differences, and the possible mechanisms by which they may have co-occurred.
UNASSIGNED: The co-existence of hidradenitis suppurativa and Fournier\'s gangrene poses unique challenges, given the rapid progression of Fournier\'s gangrene within the context of hidradenitis suppurativa, potentially suggesting the latter as a predisposing factor. This case underscores the importance of vigilant screening and management of hidradenitis suppurativa.
CONCLUSIONS: Clinicians should be aware of the potential association between hidradenitis suppurativa and Fournier\'s gangrene, especially in patients with shared risk factors.Both conditions present diagnostic and treatment challenges, emphasising the importance of a thorough differential diagnosis and a tailored selection of antibiotics.Proactive and continuous care is crucial in managing chronic diseases such as hidradenitis suppurativa to prevent severe complications, for example Fournier\'s gangrene.

BACKGROUND: Staphylococcus aureus is responsible for the majority of skin and soft tissue infections, which are often diagnosed at a late stage, thereby impacting treatment efficacy. Our study was designed to reveal the physiological changes at different stages of infection by S. aureus through the combined analysis of variations in the skin microenvironment, providing insights for the diagnosis and treatment of S. aureus infections.
METHODS: We established a murine model of skin and soft tissue infection with S. aureus as the infectious agent to investigate the differences in the microenvironment at different stages of infection. By combining analysis of the host immune status and histological observations, we elucidate the progression of S. aureus infection in mice.
RESULTS: The results indicate that the infection process in mice can be divided into at least two stages: early infection (1-3 days post-infection) and late infection (5-7 days post-infection). During the early stage of infection, notable symptoms such as erythema and abundant exudate at the infection site were observed. Histological examination revealed infiltration of numerous neutrophils and bacterial clusters, accompanied by elevated levels of cytokines (IL-6, IL-10). There was a decrease in microbial alpha diversity within the microenvironment (Shannon, Faith\'s PD, Chao1, Observed species, Simpson, Pielou\'s E). In contrast, during the late stage of infection, a reduction or even absence of exudate was observed at the infected site, accompanied by the formation of scabs. Additionally, there was evidence of fibroblast proliferation and neovascularization. The levels of cytokines and microbial composition gradually returned to a healthy state.
CONCLUSIONS: This study reveals synchrony between microbial composition and histological/immunological changes during S. aureus-induced SSTIs.

Systemic amyloidosis is a multiorgan deposition of misfolded amyloid protein fibrils. The systemic amyloid A protein (AA) amyloidosis type predominantly involves the kidney and is mostly an under-recognized complication among persons who inject drugs. Gastrointestinal involvement in systemic AA amyloidosis that is associated with illicit drug use is uncommon. In this report, we present a case of a 40-year-old man with history of injection drug use, recurrent skin and soft-tissue infection, and renal AA amyloidosis that presented with painless bloody bowel movement, which initially resolved with conservative management. Upon further evaluation, the patient was found to have empyema that required antibiotic therapy and bilateral pleural drain. His hospital course was further complicated by multiple episodes of hematochezia requiring gastrointestinal consultation. Subsequent gastrointestinal biopsy revealed amyloid deposit.

Clindamycin is a highly effective antibiotic of the lincosamide class. It has been widely used for decades to treat a range of skin and soft tissue infections in dermatology and medicine. Clindamycin is commonly prescribed for acne vulgaris, with current practice standards utilizing fixed-combination topicals containing clindamycin that prevent Cutibacterium acnes growth and reduce inflammation associated with acne lesion formation. Certain clinical presentations of folliculitis, rosacea, staphylococcal infections, and hidradenitis suppurativa are also responsive to clindamycin, demonstrating its suitability and versatility as a treatment option. This review describes the use of clindamycin in dermatological practice, the mechanism of protein synthesis inhibition by clindamycin at the level of the bacterial ribosome, and clindamycin\'s anti-inflammatory properties with a focus on its ability to ameliorate inflammation in acne. A comparison of the dermatologic indications for similarly utilized antibiotics, like the tetracycline class antibiotics, is also presented. Finally, this review addresses both the trends and mechanisms for clindamycin and antibiotic resistance, as well as the current clinical evidence in support of the continued, targeted use of clindamycin in dermatology.