Evaluation of factors associated with surgical site infection in equine proximal interphalangeal joint arthrodesis: 54 cases (2010-2019).

BACKGROUND: The frequency of surgical site infection (SSI) following orthopaedic implant placement in horses has been reported but not compared with respect to specific antibiotic protocols administered. OBJECTIVES: To determine factors associated with SSI in horses undergoing proximal interphalangeal joint (PIPJ) arthrodesis including perioperative antibiotic protocols. METHODS: Records were evaluated (2010-2019), and horses undergoing PIPJ arthrodesis were identified. Patient signalment, supervising surgeon, reason for surgery, limb, implants placed, anaesthetic time, duration casting/coaptation postoperatively, antibiotic regimen and incidence/onset SSI were recorded. Bayesian and frequentist logistic regressions were used to estimate the contribution of covariates to infection occurrence. RESULTS: Fifty-four PIPJ arthrodeses were performed. SSI occurred in 2/54 (3.7%) on day 15,30. Arthrodesis was performed most commonly for osteoarthritis (33/54, 61.1%), fracture (11/54, 20.4%), and subluxation (5/54, 9.3%). Perioperative systemic antibiotics were administered 1-3 days (15/54, 27.8%) or > 3 days (39/54, 72.2%). Antibiotic protocols included cefazolin/gentamicin (20/54, 37%), cefazolin/gentamicin/doxycycline (14/54, 25.9%) and potassium penicillin/gentamicin (10/54, 18.5%). Regional limb perfusion was performed preoperatively 31/54 (57.4%) and postoperatively 7/54 (13%). Survival to dismissal was 98.1% (53/54 horses) with one horse euthanized due to support limb laminitis. No association was identified between antibiotic selection or duration (1-3 vs. > 3 days), pre-operative regional antibiotic perfusion, intraoperative antibiotic lavage or anaesthetic time (< or > 3 h) and SSI; however, modelling was complicated by quasi-complete or complete separation of the data. Bayesian analysis (but not frequentist analysis) indicated an association between post-operative regional antibiotic perfusion and SSI. Limitations include the retrospective nature of data collection and the low rate of infection overall. CONCLUSIONS: The prevalence of SSI in this population was lower than that in previous reports of equine orthopaedic internal fixation. There was no difference in SSI rate in cases administered systemic antibiotics for 1-3 days or >3 days, or for those horses that did or did not receive preoperative regional antibiotic perfusion.

A carbapenem-resistant Acinetobacter baumannii outbreak associated with a polymyxin shortage during the COVID pandemic: an in vitro and biofilm analysis of synergy between meropenem, gentamicin and sulbactam.

BACKGROUND: During the COVID-19 pandemic, the burden of nosocomial infections caused by MDR pathogens has caused a shortage of polymyxins. Thus, we evaluated the in vitro synergism and antibiofilm activity of antimicrobial combinations and propose a test kit for synergism against carbapenem-resistant Acinetobacter baumannii (CRAB). METHODS: Fifty-six CRAB isolates were tested for synergy between meropenem, gentamicin and ampicillin/sulbactam. MICs were determined by broth microdilution. Synergism was tested using chequerboard analysis, followed by a time-kill curve. Additionally, minimum biofilm eradication concentration was determined and the antibiofilm activity of the combinations was evaluated by MTT assay and biomass reduction. A test kit was developed for routine laboratory testing to detect synergism. RESULTS: All CRAB isolates were resistant to gentamicin and ampicillin/sulbactam. Chequerboard synergism occurred against 75% of the isolates. Meropenem + ampicillin/sulbactam was the most frequent combination with synergism (69%), followed by ampicillin/sulbactam + gentamicin (64%) and meropenem + gentamicin (51%). All combinations presented only bacteriostatic activity and no bactericidal or antibiofilm effects. The routine laboratory test showed 100% accuracy compared with other in vitro assays. CONCLUSIONS: Our study demonstrates the potential role of antibiotic combinations against planktonic bacteria. In vitro synergism is possible and can be an alternative treatment for patients with CRAB infection during a polymyxin shortage.

Facile Synthesis of Bio-Antimicrobials with "Smart" Triiodides.

Multi-drug resistant pathogens are a rising danger for the future of mankind. Iodine (I2) is a centuries-old microbicide, but leads to skin discoloration, irritation, and uncontrolled iodine release. Plants rich in phytochemicals have a long history in basic health care. Aloe Vera Barbadensis Miller (AV) and Salvia officinalis L. (Sage) are effectively utilized against different ailments. Previously, we investigated the antimicrobial activities of smart triiodides and iodinated AV hybrids. In this work, we combined iodine with Sage extracts and pure AV gel with polyvinylpyrrolidone (PVP) as an encapsulating and stabilizing agent. Fourier transform infrared spectroscopy (FT-IR), Ultraviolet-visible spectroscopy (UV-Vis), Surface-Enhanced Raman Spectroscopy (SERS), microstructural analysis by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), and X-Ray-Diffraction (XRD) analysis verified the composition of AV-PVP-Sage-I2. Antimicrobial properties were investigated by disc diffusion method against 10 reference microbial strains in comparison to gentamicin and nystatin. We impregnated surgical sutures with our biohybrid and tested their inhibitory effects. AV-PVP-Sage-I2 showed excellent to intermediate antimicrobial activity in discs and sutures. The iodine within the polymeric biomaterial AV-PVP-Sage-I2 and the synergistic action of the two plant extracts enhanced the microbial inhibition. Our compound has potential for use as an antifungal agent, disinfectant and coating material on sutures to prevent surgical site infections.

Tetracycline as an inhibitor to the SARS-CoV-2.

The coronavirus severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) remains an extant threat against public health on a global scale. Cell infection begins when the spike protein of SARS-CoV-2 binds with the human cell receptor, angiotensin-converting enzyme 2 (ACE2). Here, we address the role of tetracycline as an inhibitor for the receptor-binding domain (RBD) of the spike protein. Targeted molecular investigation show that tetracycline binds more favorably to the RBD (-9.40 kcal/mol) compared to doxycycline (-8.08 kcal/mol), chloroquine (-6.31 kcal/mol), or gentamicin (-4.83 kcal/mol) while inhibiting attachment to ACE2 to a greater degree (binding efficiency of 2.98 kcal/(mol nm2 ) for tetracycline-RBD, 5.16 kcal/(mol nm2 ) for doxycycline-RBD, 5.59 kcal/(mol nm2 ) for chloroquine-RBD, and 7.02 kcal/(mol nm2 ) for gentamicin-RBD. Stronger inhibition by tetracycline is verified with nonequilibrium PMF calculations, for which the tetracycline-RBD complex exhibits the lowest free energy profile along the dissociation pathway from ACE2. Tetracycline binds to tyrosine and glycine residues on the viral contact interface that are known to modulate molecular recognition and bonding affinity. These RBD residues also engage in significant hydrogen bonding with the human receptor ACE2. The ability to preclude cell infection complements the anti-inflammatory and cytokine suppressing capability of tetracycline; this may reduce the duration of ICU stays and mechanical ventilation induced by the coronavirus SARS-CoV-2.

Sinusitis caused by a rare organism, Cedecea lapagei.

A 45-year-old man presented with acute sinusitis. He was treated with a 10-day course of trimethoprim/sulfamethoxazole, and a subsequent 14-day course of amoxicillin-clavulanate with no improvement in symptoms. Culture of purulent nasal secretions revealed the rare enterobacter Cedecea lapagei The patient had complete resolution of his symptoms after a 14-day course of gentamicin/dexamethasone nasal rinses. Emerging pathogens have been a timeless concern for physicians, as witnessed by the current SARS-CoV-2 outbreak. C. lapagei has been reported to cause human infection only a dozen times since its discovery, all in severely compromised patients. This is the first documented case of sinusitis reported with C. lapagei and may portend a rising prevalence of disease burden in the general population. This case demonstrates the necessity of obtaining cultures when standard antibiotics result in treatment failure.