Methicillin-resistant Staphylococcus pseudintermedius (MRSP) has become increasingly widespread in veterinary medicine, with a reported prevalence of up to 40.5% in dogs with pyoderma. Previous studies have shown that curcumin derived from turmeric (Curcuma longa L.) exhibits a synergistic effect when combined with β-lactam antibiotics, fluoroquinolones, tetracyclines, or vancomycin against strains of Staphylococcus aureus, including both methicillin-resistant (MRSA) and methicillin-susceptible (MSSA) isolates. Thus, the purpose of this study was to determine whether curcumin (500 µg/mL), in combination with oxacillin, amoxicillin-clavulanate, clindamycin, or doxycycline, could improve the susceptibility status of each antibiotic against multidrug-resistant Staphylococcus pseudintermedius (MDR-SP). Clinical isolates collected from dogs with MDR-SP pyoderma were tested against each antibiotic at their respective Clinical and Laboratory Standards Institute resistant, intermediate, and susceptible concentrations, in the presence or absence of curcumin. An ATCC methicillin-susceptible S. pseudintermedius reference strain (ATCC 49444) was included as an internal quality control. Exact McNemar test was used to assess paired isolate-level comparisons and a value of p < 0.05 was considered significant. A significant shift toward susceptibility was observed when curcumin was combined with oxacillin at the resistant (p = 0.001) and the susceptible (p < 0.0001) concentrations and with amoxicillin-clavulanate at the resistant (p = 0.002) and intermediate (p = 0.0078) concentrations. Amoxicillin-clavulanate at the susceptible concentration when combined with curcumin was not significant (p = 0.0625). Curcumin did not significantly alter the susceptibility status of clindamycin or doxycycline at any of the tested concentrations. Bactericidal concentrations were not observed at the tested concentrations. These results suggest that curcumin may potentiate the efficacy of select β-lactam antibiotics against MDR-SP, supporting curcumin as a potential β-lactam adjuvant against MDR-SP in vitro and warranting further evaluation.

Buruli ulcer (BU), a neglected tropical disease caused by Mycobacterium ulcerans (Mul), is treated with an 8-week regimen of rifampicin (RIF) and clarithromycin (CLA). Clinical trials are currently evaluating amoxicillin/clavulanate (AMX/CLV) co-administration to reduce treatment duration. However, conventional methods for assessing in vitro drug efficacy against Mul, like colony-forming units (CFUs), are slow and cumbersome. The ribosomal RNA synthesis ratio (RS-ratio) measures ribosome biogenesis and serves as a proxy of metabolic activity. While it is a promising predictive biomarker for treatment shortening in tuberculosis, its application in Mul remains unexplored. Here, we evaluated the RS-ratio for Mul drug activity assessment through RNA extractions from time-kill assays using RIF, CLA, and AMX/CLV, alone or in combinations. RIF + AMX/CLV-containing combinations produced a potent, rapid RS-ratio reduction, decreasing from a baseline of ≈2000 to ≈200 as early as day 3, and reaching their maximal inhibition (≈50-60) between days 7 and 10. Notably, this metabolic decline preceded the CFUs and luminescence drops observed in prior studies. Interestingly, the RS-ratio detected a metabolic recovery between days 14 and 28 (≈400), suggesting remaining bacterial viability, a phenomenon not observed by CFUs or luminescence. In summary, this is the first report using the RS-ratio to evaluate antibiotic activity against Mul. Our findings validate the RS-ratio as a molecular tool for assessing the sterilizing potential of new regimens to inform future research and clinical trial designs for the treatment of BU. Our results support the RIF + CLA + AMX/CLV regimen selection for BU treatment shortening in the BLMs4BU clinical trials (NCT05169554, PACTR202209521256638).

We present a rare case of fulminant Capnocytophaga canimorsus septicaemia in a previously well 52-year-old immunocompetent woman, following a minor dog-related forehead abrasion. Despite a recent course of amoxicillin/clavulanate prescribed by her general practitioner, the patient developed profound sepsis characterised by disseminated intravascular coagulation (DIC), multiorgan dysfunction syndrome (MODS) and severe metabolic derangements. Initial symptoms included confusion, diarrhoea and nausea, rapidly progressing to circulatory shock and acute renal failure requiring intubation and continuous renal replacement therapy. Blood cultures later confirmed C. canimorsus, and antimicrobial therapy was rationalised accordingly. Radiological evidence revealed bilateral renal cortical necrosis, ultimately resulting in end-stage renal disease and ongoing dialysis dependency. This case is notable as one of the few documented instances of renal cortical necrosis due to Capnocytophaga infection and the only known case in which the patient survived. It highlights the diagnostic and therapeutic challenges of managing rare zoonotic infections, especially in patients without traditional risk factors. Clinicians should maintain a high index of suspicion for Capnocytophaga spp. in cases of sepsis of unclear origin, particularly with any history of animal exposure, and involve infectious disease specialists early during care.

Shiga toxin-producing Escherichia coli (STEC) is a pathotype of E. coli associated with a wide variety of diarrhoea in neonatal calves, causing a global economic loss in the dairy industry with significant zoonotic risks via STEC and intimin-producing STEC, resulting in enteric and systemic illness, including diarrhoea, haemorrhagic colitis (HC), and haemolytic uremic syndrome (HUS) in humans. The presence of multidrug-resistant (MDR) STEC in neonatal diarrhoeic calves represents a significant public health concern and limits available therapeutic options. This study investigated the presence of extended-spectrum β-lactamase (ESBL) and carbapenemase-producing STEC isolates and their genotypic combinations of virulence and resistance genes in diarrhoeal calves. A total of 75 rectal swabs from diarrhoeic calves aged ≤ 12 weeks were sampled from three districts of Bangladesh, screened using selective culture and polymerase chain reaction (PCR), followed by phenotypic antimicrobial susceptibility profiling and phenotypic and genotypic screening for ESBL- and carbapenemase-production. The E. coli isolation rate among diarrhoeic calves was 80% (60/75; 95% CI: 69.17-88.35). PCR screening revealed the presence of stx1, stx2, and eae virulence genes, and the prevalence of E. coli isolates harbouring these virulence genes was 13.33% (10/75; 95% CI: 6.5-23.1). The ten virulent isolates included five stx-positive, four stx/eae-positive and one eae-positive E. coli. All the virulent isolates (100%) were resistant to ciprofloxacin and meropenem; however, eight (80%) of the tested isolates were susceptible to gentamycin, and 60% were susceptible to amoxicillin-clavulanate. All virulent E. coli isolates were MDR. We observed that 5 (50%) of the virulent E. coli isolates were ESBL producers, and 7 (70%) were carbapenemase producers. The results for phenotypes and genotypes of ESBL- and carbapenemase-producing strains were not concordant. At least one ESBL gene was present in nine of the ten virulent isolates examined, including four ESBL phenotype-negative isolates. Carbapenemase-producing genotypes were significantly more common in isolates with multiple virulence genes than in those with a single virulence gene (p = 0.001). To the best of our knowledge, this is the first report on ESBL- and carbapenemase-producing MDR STEC in diarrhoeic calves in Bangladesh.

Gordonia bronchialis is a rare aerobic, gram-positive, weakly acid-fast actinomycete that is increasingly recognized as a human pathogen following advances in microbiologic identification. However, it remains frequently misidentified because of phenotypic overlap with Mycobacterium and Nocardia species. Musculoskeletal infections caused by this organism are exceptionally uncommon. We report a 67-year-old immunocompetent male farmer who presented with a one-year history of progressive swelling and functional impairment of the right wrist and hand. Magnetic resonance imaging demonstrated chronic flexor tenosynovitis with extensive rice body formation. The patient underwent open surgical tenosynovectomy. Routine bacterial, fungal, and molecular investigations were negative. Synovial tissue submitted for mycobacterial culture yielded slow-growing colonies after prolonged incubation, which were identified as G. bronchialis using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. Prolonged oral antimicrobial therapy with amoxicillin-clavulanate, doxycycline, and ciprofloxacin resulted in marked clinical improvement without recurrence. This case highlights G. bronchialis as a rare cause of chronic tenosynovitis mimicking tuberculous infection and underscores the importance of extended culture incubation and advanced diagnostic techniques in evaluating indolent, culture-negative musculoskeletal infections.

Background: Ceftobiprole is an advanced-generation cephalosporin approved in Europe in 2013 for various indications, and in the United States (US) in 2024 for community-acquired bacterial pneumonia (CABP), acute bacterial skin and skin structure infections, and Staphylococcus aureus bacteremia, including right-sided endocarditis. Methods: The in vitro activity of ceftobiprole and comparators was evaluated against 2793 Streptococcus pneumoniae causing lower respiratory tract infections in 32 US sites (2016-2020), including against subsets from various geographic regions, resistance phenotypes and prevalent serotypes. Results: Ceftobiprole inhibited 99.5% of all S. pneumoniae at the MIC of ≤0.5 mg/L (MIC50/90, 0.015/0.25 mg/L). Susceptibilities of 98.2% to 100% were observed for ceftobiprole against isolates originating from each surveyed year or each US Census Division. Ceftobiprole retained activity against isolates resistant to macrolides (98.8%), tetracycline (98.2%), oral penicillin (95.4%), against multidrug-resistant isolates (97.0%), and various serotypes (93.8-100%). Ceftriaxone (97.4%) and amoxicillin-clavulanate (95.1%) also showed elevated susceptibilities overall, but inconsistent results and lower than those observed for ceftobiprole were noted against isolates with elevated penicillin MIC or specific serotypes (i.e., 19A). Conclusions: These in vitro results, coupled with documented clinical efficacy, indicate that ceftobiprole is a valuable option to treat CABP caused by S. pneumoniae in the US.