Cefalexin residues in aquatic environments require detection methods that are fast, label-free, and spectroscopically reliable. Surface-enhanced Raman spectroscopy (SERS) can provide molecular fingerprints, but its analytical performance depends on analyte adsorption and the spatial consistency of the enhanced response. Here, a three-dimensional silica photonic microsphere (SPM) substrate was modified with graphene oxide (GO) and gold nanoparticles (AuNPs) to form an SPM@GO@AuNPs substrate for cefalexin fingerprinting in water. GO served as an AuNP-anchoring layer and as an adsorption interface that enriched cefalexin near SERS-active AuNP junctions, whereas the monodisperse SPM provided a curved, readily handled three-dimensional support. Cefalexin bands at 768, 833, 996, 1022, and 1189 cm-1 were resolved, with the 1189 cm-1 band used for quantification. Under optimized conditions, the method exhibited a linear range of 0.01-10 μg/mL, a limit of detection of 0.41 μg/mL, and a 10 min binding step. Cefalexin was distinguished from four cephalosporin analogues using the full spectral fingerprint rather than a single band. Spiked tap-water analysis gave mean recoveries of 86.99-96.83%, supporting the feasibility of direct aqueous screening. The method is best suited to rapid fingerprint-based screening of cefalexin in relatively simple water matrices.

Acute bacterial infection of the lip is uncommon and may initially resemble traumatic, allergic, inflammatory, viral, or odontogenic disease. A 26-year-old Caucasian man developed a painful furuncle-like lesion on the lower-lip vermilion after an arthropod bite while travelling in Mexico. Within 48 h, the lesion progressed to marked lower-lip oedema, severe pain, ulceration, crusting, purulent drainage, and fever, despite local incision and oral amoxicillin-clavulanate. After urgent reassessment in Italy, repeat drainage was performed and empirical intravenous vancomycin was started. Ultrasonography showed diffuse hypoechoic oedematous thickening without a definite collection, whereas maxillofacial computed tomography demonstrated a 30 × 16 x 17 mm paramedian abscess with hyperaemic walls and a thin tract towards the cutaneous surface. Purulent material grew methicillin-susceptible Staphylococcus aureus resistant to penicillin and tetracycline, while blood cultures remained negative. Clinical improvement was evident within 48 h after repeat drainage and intravenous therapy, allowing de-escalation to oral cephalexin with complete resolution after a 7-day course. This case illustrates how rapidly progressive lip swelling may conceal an organised abscess, particularly when early source control is incomplete. In this anatomical site, persistent progression despite initial treatment should prompt microbiological sampling, cross-sectional imaging when ultrasonography is inconclusive, timely drainage, and culture-guided antimicrobial de-escalation.

Introduction: Photobiomodulation (PBM) is one of the alternatives to opioid analgesics to reduce post-operative pain. The aim of this study was to investigate the immediate, short-term, and long-term effects of PBM on chronic post-surgical pain after tympanomastoidectomy. Methods: A total of 138 subjects who had undergone tympanomastoidectomy were selected randomly and divided into two groups: PBM and control. Patients in the PBM group (n=64) received laser therapy (energy density of 8 j/cm2, wavelength of 980 nm, and power of 50 mW in 8 points behind the ear during ten sessions every day) with routine drug therapy, while patients in the control group (n=64) received only routine drug therapy (Dexamethasone, cephalexin 500 mg, acetaminophen 500 mg). The visual analogue scale (VAS) and the headache subscale of the neck disability index (NDI) were provided to both groups to assess pain intensity before the intervention, after sessions one and five, and at one- and three-month follow-ups. The between-group comparison was made through the Mann-Whitney U test, and the within-group comparison was performed using the Friedman test with pairwise comparisons. Results: No significant differences in all variables were observed between the two groups at baseline (P>0.05). The between-group comparison showed significantly lower VAS scores in PBM compared to the control group at all four time points of the study, resulting in a very large effect size at session 5, month 1, and month 3. Also, the PBM group had significantly lower NDI scores at session 5, month 1, and month 3 (P<0.001). The effect size was large at session 5 and very large thereafter. Conclusion: The combined effects of PBM and drugs may reduce pain intensity in short-term and long-term follow-ups in patients after tympanomastoidectomy. Nevertheless, PBM did not show immediate effects on pain. The trial registration number: IRCT200808310011138N28.

Escherichia coli cells can grow in a DnaA- and oriC-independent manner in rnhA-deficient cells that lack the major RNaseH activity. This mode of replication is named cSDR (constitutive stable DNA replication) and is believed to initiate from the sites of RNA-DNA hybrids, although the detailed mechanisms of cSDR are unclear. In this study, we discovered that dif sequence and XerC/D are essential for cSDR-dependent growth. cSDR was observed in either dif or xerC/D mutant cells as efficiently as in the control cells, as measured by the incorporation of [[3]H]-thymine. However, we found that these mutants accumulate cells with extra DNA contents in the presence of rifampicin and cefalexin, suggesting accumulation of unresolved dimeric or multimeric chromosomes or that of catenated chromosomes due to potential problems in resolution of the replicated chromosomes or in decatenation process. These results indicate that site-specific recombination mediated by dif-XerC/D is essential for cSDR-dependent growth.

Five Gram-negative strains, designated BI01[T], BI02, BI1211, BI4D and BI67 isolated from the gut of the Antarctic endemic insect Belgica antarctica, were characterized by a polyphasic approach. Comparative 16S rRNA gene sequences indicated that the bacterial strains belonged to the genus Yersinia. A cgMLST-based phylogeny based on 500 concatenated core genes strongly supported a clade encompassing the 5 strains that was distinct from the currently recognized 27 species of the genus Yersinia. Average nucleotide identity (ANI) among the five strains consistently exceeded 99%, but comparisons to their closest relative, Yersinia intermedia, yielded an ANI of 93% and a digital DNA-DNA hybridization value of 51.74. Metabolic profiling further differentiated the five strains from other closely related species within the genus Yersinia, notably with respect to l-fucose and potassium 2-ketogluconate fermentation, acetoin production and an absence of pyrazinamidase activity. Interestingly, three of the five strains exhibited resistance to β-lactams (amoxicillin and amoxicillin/clavulanate) and first- and second-generation cephalosporins (cefalexin and cefoxitin) associated with the presence of the ampC gene, encoding a class C beta-lactamase, in their genome. None of the five isolates harbour the classic virulence determinants of enteropathogenic Yersinia. The DNA G+C content of the five strains is 47.8 mol%. Based on these results, they represent a novel species of the genus Yersinia, for which the name Yersinia antarctica sp. nov. is proposed. Notably, this represents the first Yersinia species reported from Antarctic terrestrial invertebrates. The type strain is BI01[T] (=CIP 112622[T]=DSM 121309[T]). The distribution of this species is not limited to Antarctica, as few publicly available genomes indicate its presence in continental Russia and the Russian Arctic, with isolates recovered from rodents, polar bears and birds.

Environmental Risk Assessments (ERAs) are a helpful tool to identify medicines that pose the greatest risk to the environment. While these are integrated into regulatory frameworks overseas, they are not yet required for medicines in Australia. As a result, there is limited local data on the volumes of pharmaceuticals entering the environment and their downstream impacts. This study uses local data to calculate predicted environmental concentration and risk quotient values for antibiotics used in the community in Australia. The results from this analysis demonstrate that the environmental risks posed by antibiotics in Australia may be significant with amoxicillin, cefalexin, clindamycin, azithromycin and phenoxymethylpenicillin predicted to exceed environmental risk thresholds. However, a sensitivity analysis revealed limitations in the accuracy of this model and demonstrated that risk quotients can vary greatly based on assumptions made by the assessor. This has implications for the applicability of current environmental risk assessment models both in Australia and overseas. Despite these limitations, this model presents several advantages as a simple method to screen for high-risk antibiotics and is still more effective than the current Australian approach of having no ERA requirements for medicines.

This study aimed to investigate the occurrence of Escherichia coli isolates in retail poultry from open-air markets and supermarkets in the metropolitan region of Belém, State of Pará, Brazil, and to characterize their antimicrobial resistance profiles and the presence of selected virulence-associated genes. In this study, 14 chicken samples were collected from open-air markets (n=7) and supermarkets (n=7) and subjected to microbiological analysis and multiplex PCR to detect the iss and tsh virulence genes. Following strain identification, antimicrobial susceptibility testing (AST) was performed to evaluate the effects of five antimicrobial agents (amoxicillin, cephalexin, doxycycline, enrofloxacin, and sulfamethoxazole). Microbiological analysis showed that E. coli was detected in 71.42% (10/14) of the chicken carcasses. In contrast, PCR detected at least one virulence gene in all positive samples, with the iss gene being identified in 100% and the tsh gene in 85.7% (12/14) Among the 25 E. coli isolates obtained from the organs of chickens from both retail sources, 76% were resistant to enrofloxacin (76%), sulfamethoxazole (40%), doxycycline (36%), amoxicillin (32%), and cephalexin (28%). These findings indicate that retail broilers may harbor E. coli strains carrying virulence genes and exhibiting multidrug resistance, suggesting a potential public health concern for food safety.

Periclitoral abscesses are uncommon occurrences that can develop spontaneously. In the United States, infrared-enhanced exercise equipment, when used with high-intensity aerobic workouts, is promoted for effective calorie burning and improved fitness. Among females, pubic grooming is widespread and can cause friction on the vulvar skin. A 17-year-old female patient initially presented with vulvar swelling and pain. After a 10-day course of oral cephalexin failed, she presented to the ED and was found to have a 2.6-cm periclitoral abscess. She had a history of participating in infrared-heated sauna workout classes and routinely shaving her genital hair. She was admitted to the hospital; however, after two days of IV antibiotics and pain control, her symptoms had not resolved. The abscess became fluctuant, and incision and drainage were performed. At four-day follow-up, the wound was healing and the edema was resolving. Preventing the initial abscess is important. A few cases have been reported in the literature, but no case has identified a risk associated with the combination of pubic grooming and high-intensity exercise using infrared-integrated equipment and sauna rooms. While temporal correlation does not imply causation, more information on periclitoral abscess formation is useful.

Green discoloration of the skin is an uncommon clinical finding that can cause significant alarm among patients and caregivers. We present the case of a 92-year-old man residing in a nursing facility with a past medical history significant for hypertension, type 2 diabetes mellitus, stage 3a chronic kidney disease, chronic venous insufficiency, prior left ankle surgery with retained internal fixation hardware, and a history of deep venous thromboses who presented to the ED with acute-onset green discoloration of his left foot. The discoloration was first noticed by the nursing staff at his facility. The patient denied pain, fever, or chills. Physical examination revealed green discoloration of the plantar surface of the left foot, bilateral lower extremity edema with stasis dermatitis, chronic skin hyperkeratosis, onychomycosis, and a superficial skin laceration on the dorsal aspect of the foot. Laboratory evaluation demonstrated elevated blood urea nitrogen and creatinine levels consistent with acute kidney injury and a normal lactate level. Radiography showed diffuse soft tissue edema without fracture. The Infectious Diseases service was consulted. Clinical assessment determined that the green discoloration was attributable to Pseudomonas aeruginosa colonization, with secondary superimposed cellulitis arising from excoriations caused by ill-fitting footwear. The patient was treated with IV cefepime followed by step-down therapy with oral cephalexin and doxycycline, along with acetic acid soaks and wound care. Blood cultures remained negative. The patient demonstrated clinical improvement and was discharged to his nursing facility with wound care follow-up. This case highlights the clinical challenge of distinguishing Pseudomonas colonization from invasive infection in elderly patients with chronic skin changes and underscores the importance of a multidisciplinary approach involving infectious diseases and wound care.