Ghada N. Al-Rawahi

Background: Ralstonia species are environmental Gram-negative bacilli increasingly linked to healthcare-associated bloodstream infection (BSI) outbreaks from contaminated medical solutions. We describe an outbreak of Ralstonia mannitolilytica BSI in which the source was identified and withdrawn within 24 hours. Methods: Following an unusual cluster of R. mannitolilytica blood cultures on 29 September 2024 at a 700-bed tertiary-care hospital in Oman, we conducted a multidisciplinary investigation including chart review, hospitalwide surveillance, environmental and product sampling, antimicrobial susceptibility testing, and pulsed-field gel electrophoresis (PFGE) of clinical and product isolates. Results: Between 29 September and 8 October 2024, 21 patients met the case definition (median age 9 yr; 62% pediatric; 62% male; 95% immunocompromised; 86% with central venous access). Newly introduced pre-filled 10 mL 0.9% sodium chloride vials from a single manufacturer yielded R. mannitolilytica with concordant clinical and product antimicrobial susceptibility profiles. PFGE of 18 clinical isolates and one product isolate demonstrated 100% genetic relatedness, confirming a single-clone outbreak. The implicated product was withdrawn within 24 hours of cluster recognition. Thirteen of 21 patients had their central catheters removed; all received intravenous trimethoprim–sulfamethoxazole. Two patients experienced bacteremia recurrence after initial line retention; no outbreak-related deaths occurred. Conclusions: Prefilled saline vials can serve as the source of clonal R. mannitolilytica BSI outbreaks in immunocompromised patients. Laboratory-driven cluster detection, multidisciplinary coordination, and rapid product suspension enabled source identification within 24 hours and limited outbreak size and severity. Vigilance after introduction of new pharmaceutical products and prompt catheter removal in catheter-associated Ralstonia BSI are essential.

The coronavirus disease 2019 (COVID-19) pandemic has placed significant burden on healthcare systems. We compared Clostridioides difficile infection (CDI) epidemiology before and during the pandemic across 71 hospitals participating in the Canadian Nosocomial Infection Surveillance Program. Using an interrupted time series analysis, we showed that CDI rates significantly increased during the COVID-19 pandemic.

We investigated epidemiologic and molecular characteristics of healthcare-associated (HA) and community-associated (CA) Clostridioides difficile infection (CDI) among adult patients in Canadian Nosocomial Infection Surveillance Program hospitals during 2015–2019. The study encompassed 18,455 CDI cases, 13,735 (74.4%) HA and 4,720 (25.6%) CA. During 2015–2019, HA CDI rates decreased by 23.8%, whereas CA decreased by 18.8%. HA CDI was significantly associated with increased 30-day all-cause mortality as compared with CA CDI (p<0.01). Of 2,506 isolates analyzed, the most common ribotypes (RTs) were RT027, RT106, RT014, and RT020. RT027 was more often associated with CDI-attributable death than was non-RT027, regardless of acquisition type. Overall resistance C. difficile rates were similar for all drugs tested except moxifloxacin. Adult HA and CA CDI rates have declined, coinciding with changes in prevalence of RT027 and RT106. Infection prevention and control and continued national surveillance are integral to clarifying CDI epidemiology, investigation, and control.

Mycoplasma orale is an obligate intracellular bacterium usually found as a commensal in the human oral cavity. Symptomatic infections with this organism are rare, but severe disease has been described in the setting of impaired humoral immunity. Here, we describe a case in which M. orale was identified from the joint fluid of a patient with septic arthritis, splenic lesions, and agammaglobulinemia. A 15-year-old boy was admitted to the hospital with fever, progressive left knee swelling, and pain. His past medical history was significant for Burkitt’s lymphoma, the treatment of which had included rituximab 6 years earlier. M. orale was identified in the synovial fluid using 16S ribosomal RNA gene sequencing. He was also found to be hypogammaglobulinemic, and imaging revealed multiple splenic lesions. He was treated with doxycycline and intravenous immunoglobulin, which resulted in complete resolution of his arthritis and other symptoms. Mycoplasma species should be suspected in patients with humoral immunodeficiency and compatible findings.

We assessed the performance, stability, and user acceptability of swab-independent self-collected saliva and saline mouth rinse/gargle sample types for the molecular detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in adults and school-aged children. Outpatients who had recently been diagnosed with COVID-19 or were presenting with suspected COVID-19 were asked to have a nasopharyngeal (NP) swab collected and provide at least one self-collected sample type.

Background: Saline mouth rinse/gargle samples have recently been shown to be a suitable option for swab-independent self-collection for SARS-CoV-2 diagnosis. We sought to evaluate a simplified process for direct reverse transcriptase PCR (RT-qPCR) testing of this novel sample type and to compare performance with routine RT-qPCR using automated nucleic acid extraction. Methods: Clinical saline mouth rinse/gargle samples were subjected to automated nucleic acid extraction (“standard method”), followed by RT-qPCR using three assays including the FDA authorized US-CDC’s N1/N2 assay, which was the reference standard for determining sensitivity/specificity. For extraction-free workflow, an aliquot of each gargle sample underwent viral heat inactivation at 65 °C for 20 minutes followed by RT-qPCR testing, without an intermediate extraction step. An in-house validated RT-qPCR lab developed test (LDT), targeting the SARS-CoV-2’s S/ORF8 genes (SORP triplex assay) and the N1/N2 US-CDC assay was used to evaluate the extraction-free protocol. To improve the analytical sensitivity, we developed a single-tube hemi-nested (STHN) version of the SORP triplex assay. Results: A total of 38 SARS-CoV-2 positive and 75 negative saline mouth rinse/gargle samples were included in this evaluation. A 100% concordance in detection rate was obtained between the standard method and the extraction-free approach for the SORP assay. An average increase of +2.63 to +5.74 of the cycle threshold (C _T ) values was observed for both the SORP and N1/N2 assay when extraction-free was compared between the standard method. The average ΔC _T [ΔC _T =C _{T(Direct PCR)} -C _{T(Extracted RNA)} ], for each of the gene targets were: S (ΔC _T = +4.24), ORF8 (ΔC _T =+2.63), N1 (ΔC _T =+2.74) and N2 (ΔC _T =+5.74). The ΔC _T for the STHN SORP assay was +1.51 and −2.05 for the S and ORF8 targets respectively, when extracted method was compared to the standard method. Conclusion: Our Gargle-Direct SARS-CoV-2 method is operationally simple, minimizes pre-analytical sample processing and is potentially implementable by most molecular diagnostic laboratories. The empirical demonstration of single-tube hemi-nested RT-qPCR, to specifically address and alleviate the widely-acknowledged problem of reduced analytical sensitivity of detection of extraction-free templates, should help diagnostic laboratories in choosing Gargle-Direct protocol for high-throughput testing.