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Antimicrobial-resistant (AMR) bacteria are an increasing concern for human and animal medicine. As a result, biosecurity measures such as cleaning and disinfection are becoming heavily relied upon to eradicate and control AMR pathogens. However, evidence of co- and cross-resistance between antimicrobials and disinfectants is rising. The influence of AMR on disinfectant tolerance is poorly understood for pathogens of veterinary and public health importance. Therefore, this study aimed to compare disinfectant tolerance of fluoroquinolone-resistant Campylobacter jejuni, livestock-associated methicillin-resistant Staphylococcus aureus, multi-drug-resistant Escherichia coli and vancomycin-resistant Enterococcus faecium, with their antibiotic-susceptible counterparts. In vitro disinfectant efficacy was assessed, in the presence of organic matter, against a panel of eight disinfectants from six classes. The disinfectant efficacy varied widely depending on bacterial species and disinfectant class. Furthermore, approved disinfectant concentrations were not always deemed effective. All four bacterial species were typically most susceptible to aldehyde and/or quaternary ammonium compound-based products. Mixed evidence was found to suggest a role of AMR in disinfectant tolerance; no role of AMR was identified in E. coli, C. jejuni or E. faecium, whereas a potential role was identified in S. aureus.

Necrotizing enterocolitis (NEC) is a devastating gastrointestinal disorder in preterm infants with a high mortality rate. The aetiology of NEC appears to be multifaceted; however, gut microbiota dysbiosis likely plays a significant role. This systematic review aimed to describe how the gut microbiota of preterm infants with NEC differs from infants without NEC (PROSPERO: CRD42022344126). Databases were searched from inception to 22 June 2022 to identify eligible studies that examined the gut microbiota composition of preterm infants with and without NEC using sequencing methods. Results were described narratively. We identified 28 eligible studies. Overall, findings were heterogeneous and no single gut microbiota signature was associated with NEC in all studies. Importantly, 3 studies reported no difference in the gut microbiota composition between NEC and healthy infants, while studies reported a difference using one or more analytical method (i.e. alpha diversity, beta diversity or differential abundance analysis). Of note, NEC (or development of NEC) was positively associated with increased detection and/or abundance of Enterobacteriaceae (n=11 studies), Clostridium (n=8) and Proteobacteria (n=2). The taxa most frequently associated with NEC (Enterobacteriaceae, Clostridium, and Proteobacteria) may play an important role in the pathogenesis of NEC and should be further explored.

Proteins facilitating bacterial cell wall (CW) biosynthesis are crucial for survival and broadly remain the target of numerous antimicrobial agents. Herein, we focused on characterizing the physiological roles of low-molecular-weight penicillin-binding proteins (LMW PBPs), with dd-carboxypeptidase (dd-CPase) activity, in Mycobacterium smegmatis. Following various combinatorial gene deletions, cell viability, colony structure and the ability to produce biofilms remained unperturbed. Whilst small changes in cellular morphology and permeability were evident, hierarchical roles could not be ascribed to specific dd-CPase homologues. Strains exposed to lysozyme exhibited low levels of compensatory expression for the remaining homologues, but this was not evident for exposure to the CW-targeting Augmentin. When tested against a broader concentration range of various antibiotics, using MIC and spotting assays, only marginal changes in drug susceptibility were evident. Strains cultured under conditions of excess NaCl or enhanced pH levels grew normally. Given the established role of remodelling in dd-CPase enzymes of other bacteria, we further assessed whether the ability to repair lysozyme-induced CW damage was compromised. With the incorporation of the fluorescent d-amino acid peptidoglycan probe, TAMRA-d-alanine, as a proxy for remodelling, no changes in staining patterns were evident. However, the frequency of cells containing unresolved septa increased in all mutant strains, suggesting a potential role for dd-CPases in the mycobacterial cell process. In conclusion, we have demonstrated that the combinatorial deletion of non-essential mycobacterial dd-CPase homologues largely has no significant impact on mycobacterial physiology or involvement in the response to the various environmental stressors tested herein.

Background. Bartonella species are increasingly recognized as a significant cause of blood culture-negative infective endocarditis. Their diagnosis is often challenging, leading to delays and suboptimal treatment outcomes. Case report. This report includes a concise literature review and a case involving a 77-year-old male with a history of bovine aortic valve replacement. The patient presented with lethargy, fever, unintentional weight loss and acute kidney injury. Despite repeated blood cultures and extensive diagnostic evaluations yielding negative results, the definitive diagnosis was achieved post-surgery when valve PCR identified Bartonella species, likely linked to cat exposure. The patient was successfully treated with an extended course of doxycycline and rifampicin, leading to clinical resolution. Conclusion. This case highlights the diagnostic complexities of Bartonella endocarditis, including negative blood cultures, subacute clinical presentation and its ability to mimic autoimmune glomerulonephritis, leading to unnecessary immunosuppressive therapy. It underscores the need for improved diagnostic approaches and clinician awareness to identify at-risk populations, such as those with cat exposure or poor hygiene, ensuring the correct diagnostic investigation for an early antibiotic intervention.

Background. Carbapenem-resistant Gram-negative bacteria (CR-GNB), particularly metallo-β-lactamase (MBL) producers, are WHO critical-priority pathogens. In Libya, laboratory-based data are scarce, and no study has assessed endemic medicinal plants as adjunctive options. Objectives. To generate baseline data on carbapenem resistance and MBL production among clinical Gram-negative pathogens in Misurata, Libya, and to preliminarily evaluate the antibacterial activity and phytochemical composition of Arbutus pavarii extracts. Methods. We conducted a cross-sectional study of 244 non-duplicate clinical isolates. Carbapenem susceptibility was determined by Kirby-Bauer disc diffusion; MBL production was confirmed by double-disc synergy and combined-disc tests. Ethanolic and aqueous extracts from A. pavarii leaves, stems and fruits were tested against resistant isolates by disc diffusion. Phytochemicals were profiled by HPLC. Results. The predominant carbapenem-resistant species were Acinetobacter baumannii (29.5%), Klebsiella pneumoniae (26.2%) and Pseudomonas aeruginosa (19.7%). Resistance to both imipenem and meropenem exceeded 60% across these isolates, and MBL activity was detected in 54.5% of carbapenem-resistant K. pneumoniae. Among plant extracts, the aqueous leaf extract showed the highest antibacterial activity against MBL-producing isolates (mean inhibition zone 9.46±7.61 mm at 100%), slightly exceeding the corresponding ethanolic extract (9.31±7.30 mm). Both extracts demonstrated concentration-dependent effects (P<0.05; ANOVA/Kruskal-Wallis). HPLC analysis identified catechin and quercetin as major components, which may underlie the observed activity. Conclusions. This first laboratory-based report from Libya documents high rates of CR-GNB and MBL production and introduces A. pavarii as a promising endemic plant with adjunctive antibacterial potential. Findings support enhanced AMR surveillance and the exploration of resource-sensitive alternatives in African healthcare settings.

Tuberculosis (TB) remains a large global health threat, including increasing cases in generally low-incidence areas of the USA. However, the knowledge, attitudes and practices (KAP) regarding TB in these low-incidence areas are underexplored, precluding planning for effective health communication in these areas regarding travel to high-incidence areas or potential future outbreaks in currently low-incidence areas. Using the health belief model as a theoretical framework, we developed a KAP survey to assess public perceptions of TB in Colorado, a currently low-incidence area. We collected complete responses from n=225 adults. We found that participants had higher self-assessed knowledge than actual knowledge about TB. We also found that while participants recognized TB as a global health threat, they were not personally worried about contracting TB. However, a portion of participants indicated that they would feel shame if they contracted TB. Public knowledge and risk perception about TB could be improved by providing information in low-incidence areas on the public health burden of TB. Additionally, providing health communication to focus on emotion management and reducing stigma about the disease would be important to promote healthcare-seeking and treatment compliance in case of a future outbreak.

The rise of multidrug-resistant Enterobacterales and Pseudomonas aeruginosa has diminished the reliability of conventional antibiotics for treating Multidrug Resistant (MDR) infections. The combination of ceftazidime-avibactam with aztreonam has demonstrated in vitro synergism against multidrug-resistant organisms, notably metallo-beta-lactamase-producing strains. Treatment with the ceftazidime-avibactam/aztreonam combination may provide clinical benefits for patients with multidrug-resistant bacterial infections. The present study aimed to detect genes encoding carbapenem resistance in clinical strains and to determine the efficacy of ceftazidime-avibactam/aztreonam against carbapenemase co-producers. A cross-sectional research study was conducted on 62 carbapenem-resistant clinical isolates collected from November 2022 to February 2024. Ceftazidime-avibactam/aztreonam synergy against 55 carbapenemase producers [New Delhi metallo-beta-lactamase (NDM), imipenem-hydrolysing metallo-beta-lactamase (IMP), Verona Integron-encoded metallo-beta-lactamase (VIM) and oxacillinase-48 (OXA-48)] was determined using the disc diffusion method. Data analysis was performed by chi-square test. Ceftazidime-avibactam/aztreonam synergy was identified against 25 (64.1%) out of 39 isolates exhibiting the NDM gene, seven (77.8%) out of nine isolates that were co-producers of NDM and OXA-48 genes, two (50%) out of four isolates co-producing NDM and VIM carbapenemase genes and a single isolate (33.3%) out of three isolates with NDM, VIM and OXA-48 genes. A wide zone of 3-23 mm diameter was observed for Enterobacterales and 6-7 mm for P. aeruginosa with ceftazidime-avibactam/aztreonam in relative to ceftazidime-avibactam and aztreonam discs when tested alone. More than 30% of isolates showed a statistically significant difference in zone diameter for the ceftazidime-avibactam/aztreonam combination (P<0.05), when compared with the zone size for ceftazidime-avibactam and aztreonam discs when tested alone. The present study showed the in vitro effectiveness of the ceftazidime-avibactam/aztreonam combination against 63.6% of carbapenem-resistant isolates studied. The disc diffusion method requires less technical expertise, and the test result aids in identifying true clinical synergy by observing the widening of the zone diameter that exceeds the aztreonam susceptibility breakpoint.

Meyerozyma guilliermondii, a haploid yeast (phylum Ascomycota), is useful in bioprocessing and bioremediation, and is an infrequent pathogen of humans. The availability of highly accurate, long-read DNA sequencing methods provided the opportunity to improve the M. guilliermondii genome assembly. Using Pacific Biosciences (PacBio) HiFi technology, we generated a chromosome-level, telomere-to-telomere assembly for the M. guilliermondii type strain ATCC 6260. This assembly closed gaps in the current reference sequence and resolved a translocation artefact that affected the size and structure of chromosomes 4 and 5. The improved genome sequence is available publicly and will facilitate future studies of this species.

Introduction. Acute disseminated encephalomyelitis (ADEM) is a well-described neurological disorder that follows acute infection, vaccination and organ transplantation. It is characterized by sudden and widespread areas of inflammation in the central nervous system. Previous case reports have described ADEM with evidence of either recent or current herpes simplex virus type 1 infection. However, here, we report a rare, to our knowledge never before documented, case of ADEM associated with herpes simplex virus type 2 (HSV-2). Case report. A 20-year-old man presented with weakness and sensory disturbance to the lower limbs, which had gradually progressed over the preceding 7 days, with associated fever, urinary retention and bowel incontinence. Magnetic resonance imaging was in keeping with a diagnosis of ADEM with mainly spinal involvement. Lumbar puncture revealed lymphocytic pleocytosis with elevated protein, and PCR was strongly positive for HSV-2. He was treated with aciclovir and dexamethasone, along with broad-spectrum antibiotics until negative bacterial and mycobacterial culture results were obtained. His functional status improved over the following months, but, despite prolonged rehabilitation, neurological sequelae remain. Conclusion. HSV-2 may be considered a possible aetiological agent in cases of ADEM.

Background. Influenza C virus (ICV) is a lesser known member of the Orthomyxoviridae family, primarily causing respiratory tract infections in children. Co-infection with WU polyomavirus (WUPyV), a recently identified human polyomavirus, has been rarely reported. This study presents the first laboratory-confirmed case of ICV infection in Sri Lanka and its co-infection with WUPyV. Methods. Nasopharyngeal and oropharyngeal swabs were collected from children aged 3 months to 14 years with respiratory tract symptoms between November 2022 and February 2023. Samples were screened using multiplex real-time PCR (RT-PCR) and Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) RT-PCR. A nasopharyngeal swab from a 14-month-old infant showing an insignificant curve in respiratory PCR was subjected to whole-genome sequencing using the Illumina platform. Data were analysed for genomic characterization, and phylogenetic analysis was performed using the haemagglutinin-esterase gene of ICV. Results. Full-genome sequencing identified ICV and WUPyV in the sample. Phylogenetic analysis revealed that the ICV isolate belonged to the C/Sao Paulo lineage. The patient presented with mild symptoms, including fever, cough and cold, with normal inflammatory markers, and recovered with supportive care. Discussion. This case highlights the importance of considering ICV in paediatric respiratory illnesses, despite its under-diagnosis due to limited diagnostic tools. Unlike influenza A and B, ICV lacks neuraminidase, rendering neuraminidase inhibitors ineffective. The absence of ICV in current influenza vaccines further complicates preventive strategies. Co-detection of WUPyV raises questions about its role as a co-pathogen, with its clinical significance requiring further investigation. Conclusion. This report underscores the need for enhanced molecular diagnostic techniques and surveillance to better understand the epidemiology and clinical impact of ICV and its co-infections.