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Objective This study aims to investigate accuracy of group beta Streptococcus (GBS) rectovaginal cultures at 35 to 37 weeks in predicting intrapartum colonization. Study Design Institutional review board (IRB) approved prospective cohort study of 302 women from October 2015 to May 2017. Patients had the following tests for GBS: first trimester urine culture, rectovaginal culture at 35 to 37 weeks, and intrapartum rectovaginal culture. Outcomes included accuracy of 35- to 37-week GBS rectovaginal culture in detecting results intrapartum, and accuracy of first trimester urine culture in comparison to intrapartum rectovaginal cultures. Results There was sufficient evidence of agreement between results at 35 to 37 weeks with intrapartum cultures (p = 0.001). However, agreement was weak, 11 patients (3.7%) were GBS positive intrapartum but negative at 35 to 37 weeks; and 33 patients (11%) were initially GBS positive but were negative intrapartum. Sensitivity and specificity of the 35- to 37-week culture was 69% (95% confidence interval [CI]:54–84%) and 87% (95% CI: 83–91%), respectively. There was also weak agreement between first trimester urine culture and intrapartum rectovaginal culture. Specificity for this assessment was 98% (95% CI: 97–100%) and was significantly different compared with antepartum GBS culture (p

Objective The management of incidentally found short cervical length (CL) without prior spontaneous preterm birth (PTB) can vary. While most agree on starting vaginal progesterone, management after CL shortens <10 mm varies. The purpose of this study was to elucidate current practice patterns amongst maternal–fetal medicine (MFM) specialists. Study Design We conducted an online survey of MFM attending physicians and fellows in the United States from May 2019 to April 2020. The primary outcome was management of varying CL based on gestational age. Variations in management were assessed descriptively. Results There were 236 respondents out of 400 eligible surveyed, with a response rate of 59.2%. Universal CL screening was reported by 93.6% (49.6% abdominal and 44.1% transvaginal). Management of short CL varied based on CL measurement, rather than gestational age at presentation. At CL <10 mm, management included cerclage (17.4–18.7%), vaginal progesterone (41.3–41.7%), or cerclage plus vaginal progesterone (43.4%). Between CL of 10 to 20 mm, the majority (77.4–91.9%) would start vaginal progesterone. At CL 21 to 25 mm, management varied between expectant management (45.5–48.5%) or vaginal progesterone (51.1–52.8%). Suture material used was ethylene terephthalate (47.4%) or polypropelene (31.2). Preoperative antibiotic use was reported by 22.3%, while 45.5% used them only if the amniotic membranes were exposed, and 32.2% reported no antibiotic use. Postoperative tocolytic use varied with 19.3% reporting no use, 32.6% using it always, 8.2% only after significant cervical manipulation, 22.7% after the patient is experiencing symptoms, and 17.6% using it only if the cervix is dilated on exam. After cerclage placement, 44.5% continued CL surveillance. Conclusion Substantial differences of opinion exist among MFM physicians regarding management of incidentally found short CL in patients without history of PTB. The differences in responses obtained highlight the need for evidence-based guidelines for managing this clinical scenario. Key Points There is lack of consensus on the management of incidentally found shortened CL. The purpose of this study was to elucidate current trends in CL screening and management. Substantial differences of opinion exist regarding management of incidentally found short CL. [ABSTRACT FROM AUTHOR]

ABSTRACT The global dissemination of the mobile colistin resistance (mcr) gene illustrates how the use of colistin in veterinary medicine can affect human health, exemplifying the concept of One Health. This study screened for the existence of mcr variants (from mcr-1 to mcr-10) in a 5-year collection of clinical Klebsiella short-read whole-genome sequencing (WGS) data from a tertiary hospital in China (2013 to 2018) and aimed to identify the mechanisms of mcr spread. MICs were measured for the mcr-positive isolates, and long-read sequencing was performed to complete the mcr-positive genome sequences. Six variants (mcr-1.1, mcr-8.1, mcr-8.2, mcr-9.1, mcr-9.2, and mcr-10.1) were identified in 20 genomes, with plasmids from the IncFIIK, IncHI2, IncI2, and IncX4 groups. Highly similar plasmids (coverage, >75%; nucleotide identity, >98.5%) isolated from silver gulls, chickens, pigs, wastewater treatment plants, and hospital sewage were identified in GenBank. The MICs of the mcr-1- and mcr-8-carrying isolates were ≥4 μg/mL; however, the MICs of the mcr-9- and mcr-10-carrying isolates ranged from 0.5 μg/mL to 1 μg/mL (colistin susceptible). The variants mcr-1 to mcr-9 were found only in Klebsiella pneumoniae, while mcr-10.1 was found in K. pneumoniae, Klebsiella quasipneumoniae subsp. quasipneumoniae, and Klebsiella variicola. A pair of inverted repeats (IRs) was identified for hsdSMR-ISEc36-mcr-10.1-xerC; IR-1 (5′-TCAAACGTA) was inside the attL site of xerC, indicating that mcr-10.1 was originally integrated by xerC and mobilized by ISEc36 afterwards. In conclusion, this is the first report of mcr-10.1 susceptible to colistin in three species of Klebsiella. This study shows the genetic events that happened to mcr-10.1 in a stepwise manner, with the first step being XerC integration and the second being ISEc36 mobilization. Finally, this study also highlights mcr transmission between humans and nature. IMPORTANCE Reports of mcr-1 and mcr-8 are common in China; however, few studies have reported mcr-9 and mcr-10. One reason is that the newly described variants can be phenotypically colistin susceptible and thus may not be identified. This study identified the mcr-positive clinical isolates by investigating WGS data for 2,855 Klebsiella isolates (including K. pneumoniae, K. quasipneumoniae subsp. quasipneumoniae, and K. variicola) and found three mcr-9 and three mcr-10 cases (MICs, 0.5 μg/mL to 1 μg/mL; colistin susceptible). This study also reveals a pair of perfect 9-bp IRs of ISEc36 and the precise mcr-10.1 integration and insertion events that happened to the IncFIIK plasmids. A One Health analysis of highly similar plasmid structures from human and nonhuman sources emphasizes the plasmid transmission and evolution process.

Summary: Background: Genetically distinct viral variants of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have been recorded since January 2020. The introduction of global vaccine programs has contributed to lower COVID-19 hospitalisation and mortality rates, particularly in developed countries. In late 2021, Omicron BA.1 emerged, with substantially altered genetic differences and clinical effects from other variants of concern. Shortly after dominating global spread in early 2022, BA.1 was supplanted by the genetically distinct Omicron lineage BA.2. A sub-lineage of BA.2, designated BA.5, presently has an outgrowth advantage over BA.2 and other BA.2 sub-lineages. Here we study the neutralisation of Omicron BA.1, BA.2 and BA.5 and pre-Omicron variants using a range of vaccine and convalescent sera and therapeutic monoclonal antibodies using a live virus neutralisation assay. Using primary nasopharyngeal swabs, we also tested the relative fitness of BA.5 compared to pre-Omicron and Omicron viral lineages in their ability to use the ACE2-TMPRSS2 pathway. Methods: Using low passage clinical isolates of Clade A.2.2, Beta, Delta, BA.1, BA.2 and BA.5, we determined humoral neutralisation in vitro in vaccinated and convalescent cohorts, using concentrated human IgG pooled from thousands of plasma donors, and licensed monoclonal antibody therapies. We then determined infectivity to particle ratios in primary nasopharyngeal samples and expanded low passage isolates in a genetically engineered ACE2/TMPRSS2 cell line in the presence and absence of the TMPRSS2 inhibitor Nafamostat. Findings: Peak responses to 3 doses of BNT162b2 vaccine were associated with a 9-fold reduction in neutralisation for Omicron lineages BA.1, BA.2 and BA.5. Concentrated pooled human IgG from convalescent and vaccinated donors and BNT162b2 vaccination with BA.1 breakthrough infections were associated with greater breadth of neutralisation, although the potency was still reduced 7-fold across all Omicron lineages. Testing of clinical grade antibodies revealed a 14.3-fold reduction using Evusheld and 16.8-fold reduction using Sotrovimab for the BA.5. Whilst the infectivity of BA.1 and BA.2 was attenuated in ACE2/TMPRSS2 entry, BA.5 was observed to be equivalent to that of an early 2020 circulating clade and had greater sensitivity to the TMPRSS2 inhibitor Nafamostat. Interpretation: Observations support all Omicron variants to significantly escape neutralising antibodies across a range of vaccination and/or convalescent responses. Potency of therapeutic monoclonal antibodies is also reduced and differs across Omicron lineages. The key difference of BA.5 from other Omicron sub-variants is the reversion in tropism back to using the well-known ACE2-TMPRSS2 pathway, utilised efficiently by pre-Omicron lineages. Monitoring if these changes influence transmission and/or disease severity will be key for ongoing tracking and management of Omicron waves globally. Funding: This work was primarily supported by Australian Medical Foundation research grants MRF2005760 (ST, GM & WDR), MRF2001684 (ADK and ST) and Medical Research Future Fund Antiviral Development Call grant (WDR), Medical Research Future Fund COVID-19 grant (MRFF2001684, ADK & SGT) and the New South Wales Health COVID-19 Research Grants Round 2 (SGT).

Introduction: The emergence of multidrug resistance in Bacteroides fragilis, especially the phylogenetic lineage carrying the carbapenemase gene cfiA, represents an increasing threat to human health. However, knowledge on the diversity of the multidrug-resistant strains and the genetic elements carrying the antibiotic resistance genes (ARGs) remains limited. Aim: The objective of the study was to describe the resistome in cfiA-positive B. fragilis. Methods: A collection of cfiA-positive B. fragilis from diverse human (8 bacteremias, 15 wound infections) and animal (2 chickens, 2 pigs, 6 dogs, 3 cats) sources in Hong Kong, 2015–2017 was analysed by whole genome sequencing. Results: In the 36 isolates, 13 distinct ARGs (total number 83, median 2, range 0–7 per isolate) other than cfiA were detected. ARGs encoding resistance to aminoglycosides, β-lactams, macrolides, sulphonamides and tetracyclines were carried by CTn341-like, CTnHyb-like, Tn5220-like, Tn4555-like and Tn613-like transposons and were detected in phylogenetically diverse isolates of different host sources. Only few ARGs encoding resistance to metronidazole and tetracyclines were localized on plasmids. In two chicken isolates, a novel transposon (designated as Tn6994) was found to be involved in the dissemination of multiple ARGs mediating resistance to multiple antibiotics, including metronidazole and linezolid that are critically important for treatment of anaerobic infections. In mating experiments, Tn6994 and the associated phenotypic resistance could be transferred to Bacteroides nordii recipient. Conclusion: This study illustrates the importance of transposons in the dissemination of ARGs in the cfiA-positive division of B. fragilis. One Health approach is necessary to track the dissemination of ARGs.

Abstract Intraventricular melanoma is a very rare and highly malignant disease. Safe resection is the mainstay of treatment, but no standard guidelines exist for adjuvant therapy. Early histologic and molecular diagnosis is key for improved survival.

Objectives: This study evaluated disc diffusion tests and agar screening for detecting mecA-mediated oxacillin resistance in Staphylococcus lugdunensis (S. lugdunensis). Methods: Staphylococcus lugdunensis isolates (n = 179) from diverse sources in Hong Kong during 1998–2018 were investigated by disc diffusion tests (cefoxitin and oxacillin) and inoculation onto oxacillin (1 μg/mL and 2 μg/mL) and chromID methicillin-resistant Staphylococcus aureus (MRSA) agars. The results were compared with mecA PCR as the reference. Isolates with discordant results were further tested by MIC and penicillin-binding protein 2a (PBP2a) assays. Results: Cefoxitin and oxacillin zone diameters were not distributed in ways that allowed reliable division of the mecA-positive (n = 52) and mecA-negative (n = 127) isolates. On applying the 2019 Clinical Laboratory Standards Institute (CLSI) M100 breakpoints for cefoxitin disc results, there was 88% categorical agreement (CA) and 40% very major error (VME). Screening using 2 μg/mL oxacillin agar reliably differentiated mecA-positive and mecA-negative isolates (100% CA) without any major error (ME) or VME results. The performance of screening using 1 μg/mL oxacillin agar or ChromID MRSA agar was variable (74–89% CA, 0–38% ME and 0–37% VME). The mecA-positive isolates (n = 21) that could not be detected by the cefoxitin disc test were further characterised. The cefoxitin MIC for all 21 isolates was ≤4 μg/mL. Twenty isolates had an oxacillin MIC of 1–2 μg/mL and one had an oxacillin MIC of 4 μg/mL. All had positive PBP2a results and were typed as clonal cluster 27/SCCmec V. Conclusions: These findings highlight the need to evaluate phenotypic methods using mecA-positive S. lugdunensis with different oxacillin resistance phenotypes.

Oxacillin resistance mediated by mecA in Staphylococcus lugdunensis is emerging in some geographic areas. We evaluated cefoxitin disk diffusion (DD) and a new oxacillin agar (supplemented with 2 μg/ml oxacillin and 2% sodium chloride) screen for the detection of mecA-mediated resistance in S. lugdunensis. A total of 300 consecutive, non-duplicated clinical S. lugdunensis isolates from diverse sources in Hong Kong in 2019 were tested. The categorical agreement and errors obtained between cefoxitin DD test, oxacillin agar screen and mecA PCR were analyzed. Isolates with discordant results were further tested by MIC, penicillin binding protein 2a (PBP2a) assays, population analysis and molecular typing. PCR showed that 62 isolates were mecA-positive and 238 isolates were mecA-negative. For cefoxitin DD results interpreted using S. aureus/S. lugdunensis breakpoints, the categorical agreement (CA) for two brands of Muller-Hinton agars, MH-II (Becton Dickinson) and MH-E (bioMérieux) were both 96.0%; MEs were both 0%; and VMEs were 19.4 and 12.9%, respectively. The new oxacillin agar reliably differentiated mecA-positive and mecA-negative isolates (100% CA) without any ME or VME results. The 8 isolates with false susceptibility in the cefoxitin DD testing had cefoxitin and oxacillin MICs in the susceptible range. The isolates showed heterogeneous oxacillin resistance with resistant subpopulations at low frequencies. All had positive PBP2a results and were typed as sequence type 27/SCCmec V. The findings highlight the inability of cefoxitin DD and MIC tests for reliable detection of some mecA-positive S. lugdunensis isolates.

Background: Subject C135 is one of the members of the Sydney Blood Bank Cohort, infected in 1981 through transfusion with attenuated nef/3′ long terminal repeat (LTR)-deleted HIV-1, and has maintained undetectable plasma viral load and steady CD4 cell count, in the absence of therapy. Uniquely, C135 combines five factors separately associated with control of viraemia: nef/LTR-deleted HIV-1, HLA-B57, HLA-DR13, heterozygous CCR5 Δ32 genotype and vigorous p24-stimulated peripheral blood mononuclear cell (PBMC) proliferation. Therefore, we studied in detail viral burden and immunological responses in this individual. Methods: PBMC and gut and lymph node biopsy samples were analysed for proviral HIV-1 DNA by real-time and nested PCRs, and nef/LTR alleles by nested PCR. HIV-specific antibodies were studied by Western blotting, and CD4+ and CD8+ T lymphocyte responses were measured by proliferation and cytokine production in vitro. Results: PBMC samples from 1996, but not since, showed amplification of nef alleles with gross deletions. Infectious HIV-1 was never recovered. Proviral HIV-1 DNA was not detected in recent PBMC or gut or lymph node biopsy samples. C135 has a consistently weak antibody response and a substantial CD4+ T cell proliferative response to a previously described HLA-DR13-restricted epitope of HIV-1 p24 in vitro, which augmented a CD8+ T cell response to an immunodominant HLA-B57-restricted epitope of p24, while his T cells show reduced levels of CCR5. Conclusions: Subject C135's early PCR and weak antibody results are consistent with limited infection with a poorly replicating nef/LTR-deleted strain of HIV-1. With his HLA-B57-restricted gag-specific CD8 and helper HLA-DR13-restricted CD4 T cell proliferative responses, C135 appears to have cleared his HIV-1 infection 37 years after transfusion.

Abstract Background It is well established that lung pathology and inflammation are more severe during respiratory infections complicated by the presence of both bacteria and viruses. Whilst co-infection can result in invasive pneumococcal disease and systemic inflammation, the neuroinflammatory consequences of co-infection are poorly characterised. Methods In this study, we utilised a mouse co-infection model involving Streptococcus pneumoniae (S. pneumoniae) and influenza A virus (IAV) lung infection, and we also isolated microglia for ex vivo stimulation with pneumococcus or serum amyloid A (SAA). Results Co-infection but not S. pneumoniae or IAV alone significantly increased the number of amoeboid-shaped microglia and expression of pro-inflammatory cytokines including tumour necrosis factor α (TNFα), interleukin-1β (IL-1β), interleukin-6 (IL-6), and C-C motif chemokine ligand-2 (CCL-2) in the hypothalamus. Pneumococcus was only detected in the hypothalamus of co-infected mice. In addition, the systemic inflammatory cytokines TNFα, IL-1β and IL-6 were not elevated in co-infected mice relative to IAV-infected mice, whereas SAA levels were markedly increased in co-infected mice (p