Adjunctive glucocorticoid therapy for Pneumocystis jirovecii pneumonia in solid organ transplant recipients: A multicenter cohort, 2015-2020

Solid organ transplant recipients (SOTRs) frequently receive adjunctive glucocorticoid therapy (AGT) for Pneumocystis jirovecii pneumonia (PJP). This multicenter cohort of SOTRs with PJP admitted to 20 transplant centers in Canada, the United States, Europe, and Australia, was examined for whether AGT was associated with a lower rate of all-cause intensive care unit (ICU) admission, 90-day death, or a composite outcome (ICU admission or death). Of 172 SOTRs with PJP (median [IQR] age: 60 (51.5-67.0) years; 58 female [33.7%]), the ICU admission and death rates were 43.4%, and 20.8%, respectively. AGT was not associated with a reduced risk of ICU admission (adjusted odds ratio [aOR] [95% CI]: 0.49 [0.21-1.12]), death (aOR [95% CI]: 0.80 [0.30-2.17]), or the composite outcome (aOR [95% CI]: 0.97 [0.71-1.31]) in the propensity score-adjusted analysis. AGT was not significantly associated with at least 1 unit of the respiratory portion of the Sequential Organ Failure Assessment score improvement by day 5 (12/37 [32.4%] vs 39/111 [35.1%]; P = .78). We did not observe significant associations between AGT and ICU admission or death in SOTRs with PJP. Our findings should prompt a reevaluation of routine AGT administration in posttransplant PJP treatment and highlight the need for interventional studies.

Circulating microbial cell-free DNA is increased during neutropenia after hematopoietic stem cell transplantation

We used a next-generation sequencing platform to characterize microbial cell-free DNA (mcfDNA) in plasma samples from patients undergoing allogeneic hematopoietic stem cell transplantation (allo-HCT). In this observational study, we sought to characterize plasma mcfDNA in order to explore its potential association with the immunologic complications of transplantation. We compared serially collected patient samples with plasma collected from healthy control subjects. We observed changes in total mcfDNA burden in the plasma after transplantation, which was most striking during the early posttransplant neutropenic phase. This elevation could be attributed to a number of specific bacterial taxa, including Veillonella, Bacteroides, and Prevotella (genus level). For an additional cohort of patients, we compared the data of mcfDNA from plasma with 16s-ribosomal RNA sequencing data from stool samples collected at matched time points. In a number of patients, we confirmed that mcfDNA derived from specific microbial taxa (eg, Enterococcus) could also be observed in the matched stool sample. Quantification of mcfDNA may generate novel insights into mechanisms by which the intestinal microbiome influences systemic cell populations and, thus, has been associated with outcomes for patients with cancer.

Current Epidemiology and Clinical Features of Cryptococcus Infection in Patients Without Human Immunodeficiency Virus: A Multicenter Study in 46 Hospitals in Australia and New Zealand

BACKGROUND

Patients without human immunodeficiency virus (HIV) are increasingly recognized as being at risk for cryptococcosis. Knowledge of characteristics of cryptococcosis in these patients remains incomplete.

METHODS

We conducted a retrospective study of cryptococcosis in 46 Australian and New Zealand hospitals to compare its frequency in patients with and without HIV and describe its characteristics in patients without HIV. Patients with cryptococcosis between January 2015 and December 2019 were included.

RESULTS

Of 475 patients with cryptococcosis, 90% were without HIV (426 of 475) with marked predominance in both Cryptococcus neoformans (88.7%) and Cryptococcus gattii cases (94.3%). Most patients without HIV (60.8%) had a known immunocompromising condition: cancer (n = 91), organ transplantation (n = 81), or other immunocompromising condition (n = 97). Cryptococcosis presented as incidental imaging findings in 16.4% of patients (70 of 426). The serum cryptococcal antigen test was positive in 85.1% of tested patients (319 of 375); high titers independently predicted risk of central nervous system involvement. Lumbar puncture was performed in 167 patients to screen for asymptomatic meningitis, with a positivity rate of 13.2% where meningitis could have been predicted by a high serum cryptococcal antigen titer and/or fungemia in 95% of evaluable cases. One-year all-cause mortality was 20.9% in patients without HIV and 21.7% in patients with HIV (P = .89).

CONCLUSIONS

Ninety percent of cryptococcosis cases occurred in patients without HIV (89% and 94% for C. neoformans and C. gattii, respectively). Emerging patient risk groups were evident. A high level of awareness is warranted to diagnose cryptococcosis in patients without HIV.

Immune profiling of SARS-CoV-2 infection during pregnancy reveals NK cell and γδ T cell perturbations

Pregnancy poses a greater risk for severe COVID-19; however, underlying immunological changes associated with SARS-CoV-2 during pregnancy are poorly understood. We defined immune responses to SARS-CoV-2 in unvaccinated pregnant and nonpregnant women with acute and convalescent COVID-19, quantifying 217 immunological parameters. Humoral responses to SARS-CoV-2 were similar in pregnant and nonpregnant women, although our systems serology approach revealed distinct antibody and FcγR profiles between pregnant and nonpregnant women. Cellular analyses demonstrated marked differences in NK cell and unconventional T cell activation dynamics in pregnant women. Healthy pregnant women displayed preactivated NK cells and γδ T cells when compared with healthy nonpregnant women, which remained unchanged during acute and convalescent COVID-19. Conversely, nonpregnant women had prototypical activation of NK and γδ T cells. Activation of CD4+ and CD8+ T cells and T follicular helper cells was similar in SARS-CoV-2-infected pregnant and nonpregnant women, while antibody-secreting B cells were increased in pregnant women during acute COVID-19. Elevated levels of IL-8, IL-10, and IL-18 were found in pregnant women in their healthy state, and these cytokine levels remained elevated during acute and convalescent COVID-19. Collectively, we demonstrate perturbations in NK cell and γδ T cell activation in unvaccinated pregnant women with COVID-19, which may impact disease progression and severity during pregnancy.

Circulating effector γδ T cell populations are associated with acute coronavirus disease 19 in unvaccinated individuals

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection causes severe coronavirus disease 2019 (COVID-19) in a small proportion of infected individuals. The immune system plays an important role in the defense against SARS-CoV-2, but our understanding of the cellular immune parameters that contribute to severe COVID-19 disease is incomplete. Here, we show that populations of effector γδ T cells are associated with COVID-19 in unvaccinated patients with acute disease. We found that circulating CD27^neg CD45RA⁺ CX3CR1⁺ Vδ1_effector cells expressing Granzymes (Gzms) were enriched in COVID-19 patients with acute disease. Moreover, higher frequencies of GzmB⁺ Vδ2⁺ T cells were observed in acute COVID-19 patients. SARS-CoV-2 infection did not alter the γδ T cell receptor repertoire of either Vδ1⁺ or Vδ2⁺ subsets. Our work demonstrates an association between effector populations of γδ T cells and acute COVID-19 in unvaccinated individuals.

SARS-CoV-2 infection results in immune responses in the respiratory tract and peripheral blood that suggest mechanisms of disease severity

Respiratory tract infection with SARS-CoV-2 results in varying immunopathology underlying COVID-19. We examine cellular, humoral and cytokine responses covering 382 immune components in longitudinal blood and respiratory samples from hospitalized COVID-19 patients. SARS-CoV-2-specific IgM, IgG, IgA are detected in respiratory tract and blood, however, receptor-binding domain (RBD)-specific IgM and IgG seroconversion is enhanced in respiratory specimens. SARS-CoV-2 neutralization activity in respiratory samples correlates with RBD-specific IgM and IgG levels. Cytokines/chemokines vary between respiratory samples and plasma, indicating that inflammation should be assessed in respiratory specimens to understand immunopathology. IFN-α2 and IL-12p70 in endotracheal aspirate and neutralization in sputum negatively correlate with duration of hospital stay. Diverse immune subsets are detected in respiratory samples, dominated by neutrophils. Importantly, dexamethasone treatment does not affect humoral responses in blood of COVID-19 patients. Our study unveils differential immune responses between respiratory samples and blood, and shows how drug therapy affects immune responses during COVID-19.

Integrated immune networks in SARS-CoV-2 infected pregnant women reveal differential NK cell and unconventional T cell activation

Although pregnancy poses a greater risk for severe COVID-19, the underlying immunological changes associated with SARS-CoV-2 infection during pregnancy are poorly understood. We defined immune responses to SARS-CoV-2 in pregnant and non-pregnant women during acute and convalescent COVID-19 up to 258 days post symptom onset, quantifying 217 immunological parameters. Additionally, matched maternal and cord blood were collected from COVID-19 convalescent pregnancies. Although serological responses to SARS-CoV-2 were similar in pregnant and non-pregnant women, cellular immune analyses revealed marked differences in key NK cell and unconventional T cell responses during COVID-19 in pregnant women. While NK cells, γδ T cells and MAIT cells displayed pre-activated phenotypes in healthy pregnant women when compared to non-pregnant age-matched women, activation profiles of these pre-activated NK and unconventional T cells remained unchanged at acute and convalescent COVID-19 in pregnancy. Conversely, activation dynamics of NK and unconventional T cells were prototypical in non-pregnant women in COVID-19. In contrast, activation of αβ CD4+ and CD8+ T cells, T follicular helper cells and antibody-secreting cells was similar in pregnant and non-pregnant women with COVID-19. Elevated levels of IL-1β, IFN-γ, IL-8, IL-18 and IL-33 were also found in pregnant women in their healthy state, and these cytokine levels remained elevated during acute and convalescent COVID-19. Collectively, our study provides key insight to innate T cell and NK cell perturbations occurring in pregnant women with COVID-19, which will potentially inform patient management and education for those with COVID-19 during pregnancy.

Supported by National Health and Medical Research Council, Australia

Defective Severe Acute Respiratory Syndrome Coronavirus 2 Immune Responses in an Immunocompromised Individual With Prolonged Viral Replication

We describe severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-specific immune responses in a patient with lymphoma and recent programmed death 1 (PD-1) inhibitor therapy with late onset of severe coronavirus disease 2019 disease and prolonged SARS-CoV-2 replication, in comparison to age-matched and immunocompromised controls. High levels of HLA-DR+/CD38+ activation, interleukin 6, and interleukin 18 in the absence of B cells and PD-1 expression was observed. SARS-CoV-2-specific antibody responses were absent and SARS-CoV-2-specific T cells were minimally detected. This case highlights challenges in managing immunocompromised hosts who may fail to mount effective virus-specific immune responses.

Identifying patterns in unplanned hospital admissions during the COVID-19 pandemic: a single-centre retrospective study

Background

Countries with a high prevalence of COVID‐19 have identified a reduction in crude hospital admission rates for non‐COVID‐19 conditions during the pandemic. There remains a paucity of such data from lower prevalence countries, including Australia.

Aims

To describe the patterns of unplanned hospital daily admission rates during the COVID‐19 pandemic in a major Australian metropolitan hospital, with a focus on acute medical presentations including acute coronary syndrome (ACS), stroke and falls.

Methods

This single‐centre retrospective analysis analysed hospital admission episodes between 1 March and 30 April 2020 (COVID‐19‐era) and compared this to a historical cohort during the same period between 2017 and 2019 (pre‐COVID‐19). Information collected included total admission rates and patient characteristics for ACS, stroke and falls patients.

Results

A total of 12 278 unplanned admissions was identified across the study period. The daily admission rate was lower in the COVID‐19‐era compared with pre‐COVID‐19 (46.59 vs 51.56 days, P < 0.001). There was also a reduced average daily admission rate for falls (7.79 vs 9.95 days, P < 0.001); however, similar admission rates for ACS (1.52 vs 1.49 days, P = 0.83) and stroke (1.56 vs 1.76 days, P = 0.33).

Conclusions

Public health interventions have been effective in reducing domestic cases of COVID‐19 in Australia. At our tertiary metropolitan hospital, we have observed a significant reduction in unplanned hospital admission rates during the COVID‐19‐era, particularly for falls. Public health messaging needs to focus on educating the public how to seek medical care safely and promptly in the context of the ongoing COVID‐19 crisis.

Pseudotumor presentation of CMV disease: Diagnostic dilemma and association with immunomodulating therapy

Cytomegalovirus (CMV) is a significant cause of morbidity and mortality in the immunocompromised host. Atypical presentations which include pseudotumors or "cancer mimics" have been described. The etiology of these lesions remains unclear. The authors describe two previously unpublished cases that have arisen in the context of newer immunomodulating therapy and review the existing non-HIV-associated CMV pseudotumors described in the literature.

CD8+ T cells specific for an immunodominant SARS-CoV-2 nucleocapsid epitope display high naive precursor frequency and TCR promiscuity

To better understand primary and recall T cell responses during coronavirus disease 2019 (COVID-19), it is important to examine unmanipulated severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-specific T cells. By using peptide-human leukocyte antigen (HLA) tetramers for direct ex vivo analysis, we characterized CD8⁺ T cells specific for SARS-CoV-2 epitopes in COVID-19 patients and unexposed individuals. Unlike CD8⁺ T cells directed toward subdominant epitopes (B7/N₂₅₇, A2/S₂₆₉, and A24/S_1,208) CD8⁺ T cells specific for the immunodominant B7/N₁₀₅ epitope were detected at high frequencies in pre-pandemic samples and at increased frequencies during acute COVID-19 and convalescence. SARS-CoV-2-specific CD8⁺ T cells in pre-pandemic samples from children, adults, and elderly individuals predominantly displayed a naive phenotype, indicating a lack of previous cross-reactive exposures. T cell receptor (TCR) analyses revealed diverse TCRαβ repertoires and promiscuous αβ-TCR pairing within B7/N₁₀₅⁺CD8⁺ T cells. Our study demonstrates high naive precursor frequency and TCRαβ diversity within immunodominant B7/N₁₀₅-specific CD8⁺ T cells and provides insight into SARS-CoV-2-specific T cell origins and subsequent responses.

The Role of Immunological and Clinical Biomarkers to Predict Clinical COVID-19 Severity and Response to Therapy-A Prospective Longitudinal Study

Background

The association of pro-inflammatory markers such as interleukin-6 (IL-6) and other biomarkers with severe coronavirus disease 2019 (COVID-19) is of increasing interest, however their kinetics, response to current COVID-related treatments, association with disease severity and comparison with other disease states associated with potential cytokine storm (CS) such as Staphylococcus aureus bacteraemia (SAB) are ill-defined.

Methods

A cohort of 55 hospitalized SARS-CoV-2 positive patients was prospectively recruited - blood sampling was performed at baseline, post-treatment and hospital discharge. Serum IL-6, C-reactive protein (CRP) and other laboratory investigations were compared between treatment groups and across timepoints. Acute serum IL-6 and CRP levels were then compared to those with suspected COVID-19 (SCOVID) and age and sex matched patients with SAB and patients hospitalized for any non-infectious condition (NIC).

Results

IL-6 was elevated at admission in the SARS-CoV-2 cohort but at lower levels compared to matched SAB patients. Median (IQR) IL-6 at admission was 73.89 pg/mL (30.9, 126.39) in SARS-CoV-2 compared to 92.76 pg/mL (21.75, 246.55) in SAB (p=0.017); 12.50 pg/mL (3.06, 35.77) in patients with NIC; and 95.51 pg/mL (52.17, 756.67) in SCOVID. Median IL-6 and CRP levels decreased between admission and discharge timepoints. This reduction was amplified in patients treated with remdesivir and/or dexamethasone. CRP and bedside vital signs were the strongest predictors of COVID-19 severity.

Conclusions

Knowledge of the kinetics of IL-6 did not offer enhanced predictive value for disease severity in COVID-19 over common investigations such as CRP and vital signs.

Integrated immune dynamics define correlates of COVID-19 severity and antibody responses

SARS-CoV-2 causes a spectrum of COVID-19 disease, the immunological basis of which remains ill defined. We analyzed 85 SARS-CoV-2-infected individuals at acute and/or convalescent time points, up to 102 days after symptom onset, quantifying 184 immunological parameters. Acute COVID-19 presented with high levels of IL-6, IL-18, and IL-10 and broad activation marked by the upregulation of CD38 on innate and adaptive lymphocytes and myeloid cells. Importantly, activated CXCR3⁺cT_FH1 cells in acute COVID-19 significantly correlate with and predict antibody levels and their avidity at convalescence as well as acute neutralization activity. Strikingly, intensive care unit (ICU) patients with severe COVID-19 display higher levels of soluble IL-6, IL-6R, and IL-18, and hyperactivation of innate, adaptive, and myeloid compartments than patients with moderate disease. Our analyses provide a comprehensive map of longitudinal immunological responses in COVID-19 patients and integrate key cellular pathways of complex immune networks underpinning severe COVID-19, providing important insights into potential biomarkers and immunotherapies.

Analyses of 184 immune features define kinetics of immune responses to SARS-CoV-2

Circulating T_FH1 cells in acute COVID-19 correlate with antibodies

sIL-6R levels are elevated in severe COVID-19 but do not correlate with IL-6

Elevated IL-6 and IL-18 correlate with immune cell hyperactivation

COVID-MATCH65-A prospectively derived clinical decision rule for severe acute respiratory syndrome coronavirus 2

OBJECTIVES

We report on the key clinical predictors of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and present a clinical decision rule that can risk stratify patients for COVID-19.

DESIGN, PARTICIPANTS AND SETTING

A prospective cohort of patients assessed for COVID-19 at a screening clinic in Melbourne, Australia. The primary outcome was a positive COVID-19 test from nasopharyngeal swab. A backwards stepwise logistic regression was used to derive a model of clinical variables predictive of a positive COVID-19 test. Internal validation of the final model was performed using bootstrapped samples and the model scoring derived from the coefficients, with modelling performed for increasing prevalence.

RESULTS

Of 4226 patients with suspected COVID-19 who were assessed, 2976 patients underwent SARS-CoV-2 testing (n = 108 SARS-CoV-2 positive) and were used to determine factors associated with a positive COVID-19 test. The 7 features associated with a positive COVID-19 test on multivariable analysis were: COVID-19 patient exposure or international travel, Myalgia/malaise, Anosmia or ageusia, Temperature, Coryza/sore throat, Hypoxia-oxygen saturation < 97%, 65 years or older-summarized in the mnemonic COVID-MATCH65. Internal validation showed an AUC of 0.836. A cut-off of ≥ 1.5 points was associated with a 92.6% sensitivity and 99.5% negative predictive value (NPV) for COVID-19.

CONCLUSIONS

From the largest prospective outpatient cohort of suspected COVID-19 we define the clinical factors predictive of a positive SARS-CoV-2 test. The subsequent clinical decision rule, COVID-MATCH65, has a high sensitivity and NPV for SARS-CoV-2 and can be employed in the pandemic, adjusted for disease prevalence, to aid COVID-19 risk-assessment and vital testing resource allocation.

Wohlfahrtiimonas chitiniclastica Bloodstream Infection Due to a Maggot-infested Wound in a 54-Year-Old Male

We report a case of Wohlfahrtiimonas chitiniclastica bacteremia and sepsis, in the setting of lower limb wounds with maggot infestation. This is the first documented infection by this organism in the Australasia/Pacific region, identified using matrix-assisted laser desorption ionization-time of flight mass spectrometry and 16S ribosomal ribonucleic acid sequencing. Clinicians should be aware of this emerging pathogen.

Neurosyphilis: Concordance between cerebrospinal fluid analysis and subsequent antibiotic strategy for patients undergoing evaluation of a diagnosis of neurosyphilis

INTRODUCTION

The confirmation or analysis and exclusion of a diagnosis of neurosyphilis has long presented a challenge for infectious diseases clinicians. The authors reviewed the concordance between cerebrospinal fluid (CSF) analysis and the subsequent antibiotic strategy for patients undergoing evaluation of a diagnosis of neurosyphilis.

METHODS

All patients with positive serum syphilis serology referred for CSF analysis between January 2009 and May 2016 were included. Indications for CSF analysis were determined by review of the hospital electronic medical records. CSF parameters were determined from the hospital pathology database. Cases were defined as either 'confirmed', 'supportive' of, or 'not supportive' of a diagnosis of neurosyphilis based on existing definitions. Subsequent therapy was defined as for neurosyphilis, late latent primary syphilis or no therapy based on existing guidelines.

RESULTS

Of 131 patients reviewed, 95.4% were male and HIV co-infected (74%). A confirmed diagnosis of neurosyphilis was met by fourteen patients (10.7%). All but two of these were treated with a neurosyphilis-directed regimen. Of the 58 patients treated with neurosyphilis antibiotics, 17.2% had no CSF findings suggestive of the diagnosis. Seventy-three patients were not treated for neurosyphilis; however 35 of these met the CSF criteria for a diagnosis supportive of neurosyphilis.

CONCLUSIONS

The results of routine CSF analysis in patients with a possible diagnosis of neurosyphilis are inconsistently applied in the clinical setting, calling into question the value of routine CSF. Empirical neurosyphilis treatment should be considered up front in patients with high pre-test probability of the diagnosis.

An Update in Antimicrobial Therapies and Infection Prevention in Pediatric Lung Transplant Recipients

Lung transplantation can offer life-prolonging therapy to children with otherwise terminal end-stage lung disease. However, infectious complications, like those experienced by their adult counterparts, are a significant cause of morbidity and mortality. These include bacteria, viruses, and fungi that infect the patient pretransplant and those that may be acquired from the donor or by the recipient in the months to years posttransplant. An understanding of the approach to the management of each potential infecting organism is required to ensure optimal outcomes. In particular, emphasis on aggressive preoperative management of infections in pediatric patients with cystic fibrosis is important. These include multidrug-resistant Gram-negative bacteria, fungi, and Mycobacterium abscessus, the posttransplant outcome of which depends on optimal pretransplant management, including vaccination and other preventive, antibiotic-sparing strategies. Similarly, increasing the transplant donor pool to meet rising transplant demands is an issue of critical importance. Expanded-criteria donors-those at increased risk of blood-borne viruses in particular-are increasingly being considered and transplants undertaken to meet the rising demand. There is growing evidence in the adult pool that these transplants are safe and associated with comparable outcomes. Pediatric transplanters are therefore likely to be presented with increased-risk donors for their patients. Finally, numerous novel antibiotic-sparing therapeutic approaches are on the horizon to help combat infections that currently compromise transplant outcomes.

Management of neurosyphilis: time for a new approach?

Given the long term sequelae of untreated neurosyphilis and insensitive tests to detect treponemes in the cerebrospinal fluid, questions regarding the utility of a lumbar puncture and cerebrospinal fluid analysis either to confirm or exclude neurosyphilis are raised.

Cryptococcal infection in lung transplant recipients: A 5-year retrospective review at an Australian transplant center

Cryptococcosis is a common invasive fungal infection (IFI) in solid organ transplant (SOT) recipients. Little is known about cryptococcosis in lung transplant (LTx) recipients despite having one of the highest risks of infection. The aim of this study was to describe demographic and clinical features of cryptococcal infection in LTx recipients. We performed a retrospective, observational study of cryptococcal infection in LTx recipients at The Alfred Hospital in Melbourne, Australia, from 2012 to 2017. A total of 11 cases were identified. Seven patients (64%) were male and the median age was 54.7 years (range 34-69 years). Diagnosis occurred at a median of 233 days (range 1-3650 days) post-transplant. Nine patients (82%) had isolated pulmonary infection of whom 7 (78%) were asymptomatic. All were treated with oral antifungal therapy and 1 required surgical resection of infected lung. Two patients (18%) had disseminated infection; 1 with pulmonary and central nervous system (CNS) infection and 1 with isolated CNS infection. Both patients presented with headache and brain imaging demonstrated cerebral edema, myelinosis, and leptomeningeal enhancement. One of these patients died. This study highlights the fact that cryptococcal infection should remain a consideration in asymptomatic LTx recipients, especially in the presence of non-specific nodules on chest imaging, and that the presence of headache in these patients requires urgent investigation for CNS infection.

Donor-Derived Mycoplasma hominis and an Apparent Cluster of M. hominis Cases in Solid Organ Transplant Recipients

Background

Invasive and disseminated Mycoplasma hominis infections are well recognized but uncommon complications in solid organ transplant recipients. In a single center, a cluster of M. hominis infections were identified in lung transplant recipients from the same thoracic intensive care unit (ICU). We sought to determine the source(s) of these infections.

Methods

Medical records of the donor and infected transplant recipients were reviewed for clinical characteristics. Clinical specimens underwent routine processing with subculture on Mycoplasma-specific Hayflick agar. Mycoplasma hominis identification was confirmed using sequencing of the 16S ribosomal RNA gene. Mycoplasma hominis isolates were subjected to whole-genome sequencing on the Illumina NextSeq platform.

Results

Three lung transplant recipients presented with invasive M. hominis infections at multiple sites characterized by purulent infections without organisms detected by Gram staining. Each patient had a separate donor; however, pretransplant bronchoalveolar lavage fluid was only available from the donor for patient 1, which subsequently grew M. hominis. Phylo- and pangenomic analyses indicated that the isolates from the donor and the corresponding recipient (patient 1) were closely related and formed a distinct single clade. In contrast, isolates from patients 2 and 3 were unrelated and divergent from one another.

Conclusions

Mycoplasma hominis should be considered a cause of donor-derived infection. Genomic data suggest donor-to-recipient transmission of M. hominis. Additional patients co-located in the ICU were found to have genetically unrelated M. hominis isolates, excluding patient-to-patient transmission.

Mobile phones and computer keyboards: unlikely reservoirs of multidrug-resistant organisms in the tertiary intensive care unit

Few studies have used molecular epidemiological methods to study transmission links to clinical isolates in intensive care units. Ninety-four multidrug-resistant organisms (MDROs) cultured from routine specimens from intensive care unit (ICU) patients over 13 weeks were stored (11 meticillin-resistant Staphylococcus aureus (MRSA), two vancomycin-resistant enterococci and 81 Gram-negative bacteria). Medical staff personal mobile phones, departmental phones, and ICU keyboards were swabbed and cultured for MDROs; MRSA was isolated from two phones. Environmental and patient isolates of the same genus were selected for whole genome sequencing. On whole genome sequencing, the mobile phone isolates had a pairwise single nucleotide polymorphism (SNP) distance of 183. However, >15,000 core genome SNPs separated the mobile phone and clinical isolates. In a low-endemic setting, mobile phones and keyboards appear unlikely to contribute to hospital-acquired MDROs.

A successful aggressive surgical and medical approach to pulmonary artery obstruction due to Mycobacterium abscessus infection post lung transplantation

Mycobacterium abscessus infection following lung transplantation has historically been associated with poor outcomes. We report a case of bilateral lung retransplantation complicated by obstruction of the right pulmonary artery secondary to M. abscessus mycotic aneurysm. Aggressive surgical management, including reconstruction of the right pulmonary artery, was undertaken with prolonged antimicrobial therapy. Thirty-six months later, antibiotics have been discontinued and the patient has stable soft tissue chest wall disease with good graft function. Mortality and morbidity associated with M. abscessus infection is considerable but this case illustrates that with aggressive early management, outcomes may be favorable.

Short Communication: Mycobacterium avium Complex Infection and Immune Reconstitution Inflammatory Syndrome Remain a Challenge in the Era of Effective Antiretroviral Therapy

A 10-year review of disseminated Mycobacterium avium complex (MAC) infection and MAC-immune reconstitution inflammatory syndrome in HIV-positive patients (2004-2014) at a state-wide tertiary referral HIV service demonstrates that despite advances in antiretroviral therapy, MAC infection remains a therapeutic challenge, particularly intra-abdominal disease.