Performance characteristics of genus or species-specific Polymerase Chain Reaction (PCR) for the microbial diagnosis of joint infections: A systematic review and meta-analysis.

Joint infections cause significant morbidity and mortality. Rapid diagnosis enables prompt initiation of appropriate antimicrobial therapy and surgical treatment. We conducted a systematic review and meta-analysis to evaluate the accuracy of genus- or species-specific polymerase chain reaction (PCR) in diagnosing joint infections. The literature databases were searched for articles from January 2010 to December 2022. The meta-analysis using the split component synthesis (SCS) method, included 20 studies with 2,457 adult participants. The pooled sensitivity, specificity, diagnostic odds ratio, and AUC of PCR were 49 % (95 % CI [37.9-60.2]), 95.7 % (95 % CI [91.6-97.8]), 21.32, and 0.82 respectively. Sensitivity was highest for sonicate fluid and lowest for periprosthetic tissue. The mean turnaround time to results was 4.7 hours (SD 1.1). PCR is a favourable option for diagnosing joint infections due to its rapid results, but it has low sensitivity. To enhance diagnostic yield, the test should be used in conjunction with other methods.

Post operative abdominal wall mucormycosis infection after laparotomy for bowel perforation.

Mucormycosis is a devastating disease with a high mortality rate, typically affecting immunosuppressed individuals. Postoperative surgical site infections due to mucromycosis are rare, with only a handful of cases reported in the literature. Here, we describe a fatal case of post operative abdominal wound infection caused by mucormycosis in an immunocompetent man in his 70 s, who developed the infection following a laparotomy for bowel perforation. Initially, the growth of fungal species from a superficial wound swab was not considered significant until the patient exhibited signs of worsening sepsis. Limited operative debridement was performed for prognostication, in accordance with the family's wishes. There was evidence of extensive significant invasive fungal infection, marked by necrosis extending into the abdominal wall fat and muscle. The patient was then transitioned to comfort measures and subsequently died. This case emphasizes the importance of maintaining a high level of clinical suspicion for mucormycosis, even in patients with minimal risk factors, and highlights the importance of prompt and aggressive treatment.

Home nursing and self-administered outpatient parenteral antimicrobial treatment: a comparison of demographics and outcomes from a large regional hospital in Queensland, Australia.

BACKGROUND: Outpatient parenteral antimicrobial treatment (OPAT) is a safe and effective therapy used in several settings across Australia. As OPAT services expand their inclusion criteria to include complex patient populations, there is an increased need for selecting appropriate patients to receive either healthcare-administered OPAT (H-OPAT) or self-administered OPAT (S-OPAT). AIMS: To describe patient demographics, diagnosis, microbiology and outcomes of patients treated by H-OPAT and S-OPAT within the Sunshine Coast Hospital and Health Service, Australia. METHODS: Data on demographics, diagnoses, treatment and outcomes on all patients treated by H-OPAT and S-OPAT from March 2017 to December 2019 were collected retrospectively. RESULTS: One hundred and sixty-five patients (62.26%) were enrolled in H-OPAT and 100 patients (37.74%) in S-OPAT. S-OPAT patients were significantly younger. H-OPAT patients were more comorbid. Bone and joint infections were the most treated infections and were more likely to be treated by S-OPAT. There was no difference in treatment duration, cure and complication rates between S-OPAT and H-OPAT. Longer duration of therapy was associated with more complications. Treatment failure was associated with infections due to multiple organisms, number of comorbidities and treatment of surgical site, skin and soft tissue infections. CONCLUSIONS: There were significant differences in demographics between H-OPAT and S-OPAT without any difference in outcomes. Overall failure and complication rates were low. Higher rates of treatment failure were predicted by the diagnosis, number of comorbidities and number of organisms treated.

Evaluation of a virtual ward model of care and readmission characteristics during the COVID-19 pandemic within an Australian tertiary hospital.

BACKGROUND: Virtual ward (VW) models of care established during the coronavirus disease 2019 (COVID-19) pandemic provided safe and equitable provision of ambulatory care for low-risk patients; however, little is known about patients who require escalation of care to hospitals from VWs. AIM: To assess our VW model of care and describe the characteristics of patients admitted to the hospital from the VW. METHODS: Observational study of all patients admitted to a tertiary hospital COVID-19 VW between 1 December 2021 and 30 June 2022. Utilisation and epidemiological characteristics were assessed for all patients while additional demographics, assessments, treatments and outcomes were assessed for patients admitted to the hospital from the VW. RESULTS: Of 9494 patient admissions, 269 (2.83%) patients identified as Aboriginal and Torres Strait Islander and 1774 (18.69%) were unvaccinated. The median length of stay was 5.10 days and the mean Index of Relative Socio-economic Advantage and Disadvantage decile was 5.73. One hundred sixty (1.69%) patients were admitted to the hospital from the VW, of which 25 were adults admitted to medical wards. Of this cohort, prominent comorbidities were obesity, hypertension, asthma and frailty, while the main symptoms on admission to the VW were cough, fatigue, nausea and sore throat. High Pandemic Respiratory Infection Emergency System Triage (PRIEST), Veterans Health Administration COVID-19 (VACO), COVID Home Safely Now (CHOSEN) and 4C mortality scores existed for those readmitted. CONCLUSIONS: This VW model of care was both safe and effective when applied to a broad socioeconomic population during the COVID-19 pandemic. While readmission to the hospital was low, this study identified key characteristics of such presentations, which may assist future triaging, escalation and resource allocation within VWs during the COVID-19 pandemic and beyond.

Rapid fluoroquinolone resistance detection in Pseudomonas aeruginosa using mismatch amplification mutation assay-based real-time PCR.

Background. Antimicrobial resistance (AMR) is an ever-increasing global health concern. One crucial facet in tackling the AMR epidemic is earlier and more accurate AMR diagnosis, particularly in the dangerous and highly multi-drug-resistant ESKAPE pathogen, Pseudomonas aeruginosa.Objectives. We aimed to develop two SYBR Green-based mismatch amplification mutation assays (SYBR-MAMAs) targeting GyrA T83I (gyrA248) and GyrA D87N, D87Y and D87H (gyrA259). Together, these variants cause the majority of fluoroquinolone (FQ) AMR in P. aeruginosa.Methods. Following assay validation, the gyrA248 and gyrA259 SYBR-MAMAs were tested on 84 Australian clinical P. aeruginosa isolates, 46 of which demonstrated intermediate/full ciprofloxacin resistance according to antimicrobial susceptibility testing.Results. Our two SYBR-MAMAs correctly predicted an AMR phenotype in the majority (83%) of isolates with intermediate/full FQ resistance. All FQ-sensitive strains were predicted to have a sensitive phenotype. Whole-genome sequencing confirmed 100 % concordance with SYBR-MAMA genotypes.Conclusions. Our GyrA SYBR-MAMAs provide a rapid and cost-effective method for same-day identification of FQ AMR in P. aeruginosa. An additional SYBR-MAMA targeting the GyrB S466Y/S466F variants would increase FQ AMR prediction to 91 %. Clinical implementation of our assays will permit more timely treatment alterations in cases where decreased FQ susceptibility is identified, leading to improved patient outcomes and antimicrobial stewardship.

Reducing the prevalence of antecubital fossa peripheral intravenous cannulation.

Observational studies have found that placement of peripheral intravenous cannulas (PIVCs) in the antecubital fossa (ACF) is associated with increased risks of infection, including healthcare-associated Staphylococcus aureus bacteraemia (HA-SAB). Avoiding placement of the PIVC in the ACF area along with other preventive measures such as aseptic technique, staff education on documentation, standardised insertion packs and alerts for timely removal, may reduce the overall risk of acquiring an HA-SAB. AIM: To implement a multimodal awareness programme on ACF cannulas and the risk of infection, and to reduce PIVC-associated HA-SAB in one hospital in Australia. METHOD: The authors performed a baseline digital survey to identify root causes for clinical decision making related to PIVCs and to raise awareness of the project. The authors performed weekly audits and provided feedback on four key wards over 12 weeks. Simple linear regression was used to look at the trend of ACF cannulation rates over time. HA-SAB rates were calculated per 10 000 occupied bed days. FINDINGS: Improved insertion documentation was observed during the intervention period. The ACF cannulation rates decreased by 0.03% per day during the study, although this did not quite reach statistical significance (P=0.06). There were no PIVC-associated SAB events during the intervention period. The SAB rates decreased by 0.02% per day over the period of the study.

Mycotic aortic aneurysm formation following intravesical BCG treatment for transitional cell carcinoma of the bladder.

Mycotic aneurysms are rare and if left untreated, can have devastating outcomes. In this case, a 72-year-old man presented to hospital with fevers, night sweats and abdominal pain. A CT scan revealed the development an infrarenal pseudoaneurysm over the course of 8 weeks, increasing from 2.8 cm to a 3.1 cm. The aneurysm was not present on a CT scan performed 6 months earlier. The patient underwent an emergency endovascular repair of the aortic aneurysm (EVAR) and was placed on broad-spectrum antibiotics. Intra-aortic blood cultures aspirated adjacent to the aneurysm and tissue biopsy confirmed tuberculosis bovis as the cause of the mycotic aneurysm. The patient had been treated with intravesical BCG for transitional cell carcinoma of the bladder several months prior. The patient was treated with an extended course of antituberculosis medication. He recovered well and was back to his baseline function within weeks.

Surveillance for azole resistance in clinical and environmental isolates of Aspergillus fumigatus in Australia and cyp51A homology modelling of azole-resistant isolates.

Background: The prevalence of azole resistance in Aspergillus fumigatus is uncertain in Australia. Azole exposure may select for resistance. We investigated the frequency of azole resistance in a large number of clinical and environmental isolates. Methods: A. fumigatus isolates [148 human, 21 animal and 185 environmental strains from air (n = 6) and azole-exposed (n = 64) or azole-naive (n = 115) environments] were screened for azole resistance using the VIPcheck™ system. MICs were determined using the Sensititre™ YeastOne YO10 assay. Sequencing of the Aspergillus cyp51A gene and promoter region was performed for azole-resistant isolates, and cyp51A homology protein modelling undertaken. Results: Non-WT MICs/MICs at the epidemiological cut-off value of one or more azoles were observed for 3/148 (2%) human isolates but not amongst animal, or environmental, isolates. All three isolates grew on at least one azole-supplemented well based on VIPcheck™ screening. For isolates 9 and 32, the itraconazole and posaconazole MICs were 1 mg/L (voriconazole MICs 0.12 mg/L); isolate 129 had itraconazole, posaconazole and voriconazole MICs of >16, 1 and 8 mg/L, respectively. Soil isolates from azole-exposed and azole-naive environments had similar geometric mean MICs of itraconazole, posaconazole and voriconazole (P > 0.05). A G54R mutation was identified in the isolates exhibiting itraconazole and posaconazole resistance, and the TR34/L98H mutation in the pan-azole-resistant isolate. cyp51A modelling predicted that the G54R mutation would prevent binding of itraconazole and posaconazole to the haem complex. Conclusions: Azole resistance is uncommon in Australian clinical and environmental A. fumigatus isolates; further surveillance is indicated.

A case of Shewanella algae endocarditis: an emerging pathogen with a diverse clinical spectrum.

Shewanella algae is a rare pathogen related to water exposure in temperate climates. It is commonly associated with skin and soft tissue infections, peritonitis and bacteraemia. We report the first-ever case of S. algae infective endocarditis in a patient with previous splenectomy and explore the difficulties in treatment as well as highlight the importance of this organism as an emerging pathogen.

16S-23S Internal Transcribed Spacer Region PCR and Sequencer-Based Capillary Gel Electrophoresis has Potential as an Alternative to High Performance Liquid Chromatography for Identification of Slowly Growing Nontuberculous Mycobacteria.

Accurate identification of slowly growing nontuberculous mycobacteria (SG-NTM) of clinical significance remains problematic. This study evaluated a novel method of SG-NTM identification by amplification of the mycobacterial 16S-23S rRNA internal transcribed spacer (ITS) region followed by resolution of amplified fragments by sequencer-based capillary gel electrophoresis (SCGE). Fourteen American Type Culture Collection (ATCC) strains and 103 clinical/environmental isolates (total n = 24 species) of SG-NTM were included. Identification was compared with that achieved by high performance liquid chromatography (HPLC), in-house PCR and 16S/ITS sequencing. Isolates of all species yielded a SCGE profile comprising a single fragment length (or peak) except for M. scrofulaceum (two peaks). SCGE peaks of ATCC strains were distinct except for peak overlap between Mycobacterium kansasii and M. marinum. Of clinical/environmental strains, unique peaks were seen for 7/17 (41%) species (M. haemophilum, M. kubicae, M. lentiflavum, M. terrae, M. kansasii, M. asiaticum and M. triplex); 3/17 (18%) species were identified by HPLC. There were five SCGE fragment length types (I-V) each of M. avium, M. intracellulare and M. gordonae. Overlap of fragment lengths was seen between M. marinum and M. ulcerans; for M. gordonae SCGE type III and M. paragordonae; M. avium SCGE types III and IV, and M. intracellulare SCGE type I; M. chimaera, M. parascrofulaceum and M. intracellulare SCGE types III and IV; M. branderi and M. avium type V; and M. vulneris and M. intracellulare type V. The ITS-SCGE method was able to provide the first line rapid and reproducible species identification/screening of SG-NTM and was more discriminatory than HPLC.

Case report: Sporotrichosis from the Northern Territory of Australia.

We report three cases of lymphocutaneous infection caused by the thermally dimorphic fungus, Sporothrix schenckii from Australia's tropical Northern Territory. Two cases were acquired locally, making them the first to be reported from this region. All three cases presented with ulceration in the limb; however, the classical sporotrichoid spread was present only in the first two cases. Their occurrence within several weeks of each other was suggestive of a common source of environmental contamination such as hay used as garden mulch. Diagnoses were delayed in each case, with each patient having substantial exposure to ineffective antibiotics before the correct diagnosis was made. These cases bring the total number of reported sporotrichosis cases in Australia since 1951 to 199. Lessons from these cases are to consider the diagnosis of sporotrichosis in lesions of typical appearance, even in geographical settings from where this pathogen has not previously been reported.