Clinical Microbiological Data Research Articles

168. Epidemiology, Risk Factors and Outcome of Bloodstream Infection Within the First Year After Kidney Transplantation

BackgroundBloodstream infections (BSIs) are an important cause of morbidity and mortality among kidney transplant (KT) recipients, especially within the first year. We investigated for an epidemiology, risk factors and outcome of this specific infection following KT.MethodsWe conducted a retrospective study of all adult KT recipients who developed BSI within the first year after KT from January to December 2016 at a large referral single transplant center in Bangkok, Thailand. The cumulative incidence of BSI after transplant was estimated with Kaplan–Meier methodology. Clinical characteristics, microbiological data, and outcome were extracted. Risk factors for BSI were assessed with multivariate Cox proportional hazards models.ResultsA total of 26 (15.2%) episodes of BSI occurred in 171 KT recipients, 58.5% of them were men and the mean ± SD age was 43 ± 12 years. The majority received deceased-donor allograft (58.5%) and induction therapy (59%). The Kaplan–Meier estimated for BSIs were 12.3% at 3 months, 13.5% at 6 months, and 15.2% at 12 months after KT. Gram-negative bacteria were responsible for 92% of BSI, with Escherichia coli was the most common causative pathogen (65%) and 71% of those produced extended-spectrum β-lactamases enzyme. The genitourinary tracts were the predominant source of BSIs (85%). In a multivariate analysis, the second kidney transplantation [HR, 4.55; 95% CI, 1.24–16.79 (P =0.02)] and receiving induction therapy [HR, 3.05; 95% CI, 1.15–8.10 (P<0.03)] were associated with BSI. One patient (4%) developed acute cellular rejection and one patient (4%) died from septic shock.ConclusionOne-sixth of KT recipients could develop gram-negative bloodstream infection within the first year after KT especially those underwent the second transplantation or received induction therapy. Disclosures All authors: No reported disclosures.

2198. Weak Interobserver Reliability in the Clinical Diagnosis of Pneumonia Among Infectious Disease Trained Physicians

BackgroundPneumonia remains a common global cause of death. Varied definitions of pneumonia rely on clinical features, imaging, and microbiological data. The Center for Diseases Control/National Healthcare Surveillance Network (CDC/NHSN) definition is used to study population-level trends. Prior studies have revealed discordance in components of the definition, yet reliability of overall clinical diagnosis has not been evaluated, nor has it been compared with the surveillance definitions. This study was designed to determine the overall concordance in the diagnosis of pneumonia by Infectious Diseases (ID) clinicians and the agreement between this and the surveillance definition. We then set out to determine which clinical features were weighted most heavily in provider decision-making.MethodsUsing an iterative approach with input from ID and Pulmonary Medicine physicians, we designed and refined an adjudication tool for diagnosis of pneumonia that consolidates clinical features, laboratory data, and imaging. Cases were analyzed by strict CDC/NHSN surveillance criteria and adjudicated independently by ID-trained physicians based on overall clinical opinion. Kappa coefficient (κ) was used to determine diagnostic reliability, and a random forest model was used to identify clinical factors most heavily weighted by physicians.ResultsTwenty-eight cases were adjudicated by three ID-trained physicians. Overall, interrater agreement was low (κ = 0.438). In comparing providers’ clinical adjudication with CDC/NHSN criteria, agreement was even worse (κ range 0.125 to 0.378). Among specific clinical features, positive culture growth strongly informed clinician diagnosis of pneumonia, while chest imaging did not play a significant role.ConclusionOverall agreement in the clinical diagnosis of pneumonia is poor, even among ID-trained physicians. Culture results more strongly inform clinician decision-making than does chest imaging. The surveillance definition used by the CDC/NHSN has only weak agreement with in-practice clinical assessment. These results underscore the need for more precise diagnostic tools in cases of suspected pneumonia. Disclosures All authors: No reported disclosures.

1523. Clinical Epidemiology of Children with Orbital Cellulitis

BackgroundThe microbiology of pathogens causing orbital cellulitis in children is evolving over time, with studies from around 10 years ago describing MRSA as responsible for anywhere from 0 to 13% of cases of orbital cellulitis. However, the prevalence of community-acquired MRSA infections has declined over the past decade. A current understanding of the bacteria most commonly found to be responsible for orbital cellulitis would be important to inform the empiric antibiotic regimens for cases of orbital cellulitis in which no microbiologic data are available.MethodsThis is a single-center retrospective cohort study of children ≤18 years hospitalized with orbital cellulitis at Children’s National Medical Center between January 1, 2017 and July 31, 2018. We excluded children with immunocompromising conditions, cystic fibrosis, underlying craniofacial abnormality, or recent craniofacial or otolaryngologic surgery. Baseline clinical characteristics, microbiologic data, clinical outcomes, and antibiotic treatment data were abstracted through structured chart review and summarized with descriptive statistics.ResultsWe identified 68 children that met inclusion criteria, with an average age of 8.2 years; 66.2% were male, 48.5% were African American, and 14.7% were Hispanic. Most (67.6%) had no underlying medical problems, 14.7% had asthma, and 22.1% had allergic rhinitis. The median duration of symptoms prior to presentation was 4 days. An abscess or phlegmon was identified in 41 of the 68 (60.3%). Three patients (4.4%) developed intracranial complications. About one-quarter (27.9%) of all patients in the cohort underwent surgical drainage. The most commonly identified pathogens were viridans group streptococci (7/19, 36.8%), followed by Staphylococcus aureus (4/19, 21.1%). Anti-MRSA therapy was provided empirically in almost all (95.6%) of patients.ConclusionOne-quarter of all patients hospitalized for orbital cellulitis underwent surgical drainage, and viridans group streptococci and S. aureus were the most commonly isolated pathogens. While MRSA was isolated in only one patient (5.2%), almost all received empiric anti-MRSA therapy. Disclosures All authors: No reported disclosures.

1593. Analysis of Hospital Antimicrobial Susceptibility Test Results for Patterns of Antibiotic Resistance

BackgroundAntimicrobial susceptibility tests (ASTs) are routinely performed on pathogens isolated from clinical samples. ASTs are used by clinicians to select the most appropriate treatment for antibiotic-resistant microorganisms. In aggregate, ASTs offer insight into the rise and spread of antibiotic resistance across hospitals. Here, we used ASTs to identify patterns of antibiotic resistance across drugs and microorganisms.MethodsWe conducted a retrospective analysis of 364,813 AST results from the University of Pittsburgh Medical Center from 2015 to 2018. Data regarding infection site, hospital laboratory testing, organism identification, and antibiotic susceptibilities were extracted from the laboratory information system and anonymized prior to use. The pathogens studied included Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Acinetobacter baumannii, Staphylococcus aureus, Proteus mirabilis, and Enterococcus faecalis.ResultsWe identified 21 antibiotic-pathogen combinations where resistance was found in less than 1% of AST results. Concordant susceptibility results of levofloxacin and ciprofloxacin occurred the most frequently among antibiotic pairs. Additionally, concordant susceptibility results were more common within antibiotics belonging to the same antibiotic class than between classes. P. aeruginosa had the highest rate of overall concordant results with concordance occurring within all -lactam classes. In contrast, K. pneumoniae and P. mirabilis showed the least concordance, suggesting that their resistance profiles are less predictable. Notably, we did not identify any pairs of antibiotics that strongly exhibited discordant susceptibility results regardless of the microorganism.ConclusionUsing routinely collected clinical microbiological data, we were able to characterize pathogen-antibiotic combinations where resistance is rarely seen. Additionally, we identified pairs of antibiotics that frequently exhibited concordance susceptibilities both within and between classes. Lastly, we were unable to find evidence of discordant susceptibility results, indicating that more clinical research is needed to determine the efficacy of collateral sensitivity treatment techniques.Disclosures All authors: No reported disclosures.

Microbiology Investigation Criteria for Reporting Objectively (MICRO): a framework for the reporting and interpretation of clinical microbiology data

BackgroundThere is a pressing need to understand better the extent and distribution of antimicrobial resistance on a global scale, to inform development of effective interventions. Collation of datasets for meta-analysis, mathematical modelling and temporo-spatial analysis is hampered by the considerable variability in clinical sampling, variable quality in laboratory practice and inconsistencies in antimicrobial susceptibility testing and reporting.MethodsThe Microbiology Investigation Criteria for Reporting Objectively (MICRO) checklist was developed by an international working group of clinical and laboratory microbiologists, infectious disease physicians, epidemiologists and mathematical modellers.ResultsIn keeping with the STROBE checklist, but applicable to all study designs, MICRO defines items to be included in reports of studies involving human clinical microbiology data. It provides a concise and comprehensive reference for clinicians, researchers, reviewers and journals working on, critically appraising, and publishing clinical microbiology datasets.ConclusionsImplementation of the MICRO checklist will enhance the quality and scientific reporting of clinical microbiology data, increasing data utility and comparability to improve surveillance, grade data quality, facilitate meta-analyses and inform policy and interventions from local to global levels.

Corynebacterium macginleyi-associated Blebitis: A Case Report

The purpose of this study was to report a rare case of posttrabeculectomy bleb-related infection associated with Corynebaterium macginleyi, a rare conjunctival pathogen. Case description including clinical imaging and microbiology data, and literature review of Corynebacterium macginleyi-related infections. A 60-year-old glaucomatous female patient presented with a bleb-related infection 6 years after trabeculectomy in her right eye, suggestive of blebitis. No bleb-related endophthalmitis was reported. C. macginleyi is a rare conjunctival pathogen that can cause conjunctivitis and, rarely, bleb-related infections.

RELATIONSHIP BETWEEN CLINICAL FEATURES AND CT FINDINGS IN HOSPITALIZED ADULT PATIENTS WITH COMMUNITY-ACQUIRED PNEUMONIA

SESSION TITLE: Chest Infections 2 SESSION TYPE: Original Investigation Posters PRESENTED ON: 10/10/2018 01:00 PM - 02:00 PM PURPOSE: Data on the relationship between the clinical and microbiological features of community-acquired pneumonia (CAP) and its computed tomography (CT) findings are limited. The aim of the present study was to investigate the clinic-microbiological features of patients with CAP presenting with ground-glass opacity (GGO) and centrilobular nodules or tree-in-bud pattern on CT images. METHODS: Patients with CAP that underwent a CT scan at presentation were retrospectively classified using CT findings into consolidation, GGO, and bronchiolitis groups. These three groups were compared in terms of clinical parameters and microbiological data. RESULTS: Forty (2.4%) patients were allocated to the bronchiolitis group and 46 (2.8%) to the GGO group. The most common pathogen in the bronchiolitis group was Mycoplasma pneumoniae, which was significantly more frequently isolated in this group. The bronchiolitis group was characterized by a higher percentage of cough, a lower percentage of chest pain, and lower blood levels of inflammatory markers. Common pathogens in the GGO group were not significantly different from those in the other two groups. Unlike that observed in the consolidation group, complicated parapneumonic effusion or empyema was not observed in the bronchiolitis or GGO group. Outcome variables were similar in the three groups. CONCLUSIONS: The bronchiolitis group was characterized by a higher frequency of M. pneumoniae and a less severe form of CAP. The GGO and consolidation groups was similar with respect to causative microorganisms and the clinical features of CAP. No patient in the bronchiolitis or GGO group exhibited complicated parapneumonic effusion or empyema. CLINICAL IMPLICATIONS: 1) The bronchiolitis group was associated with a higher M. pneumoniae frequency, a less severe form of CAP, and the absence of complicated parapneumonic effusion or empyema. 2) The GGO group was similar to the consolidation group in terms of causative microorganisms, severity, and prognosis, but unlike the consolidation group, was not found to be associated with complicated parapneumonic effusion or empyema. 3) The bronchiolitis and GGO groups were similar to the consolidation group in terms of 30-day or in-hospital mortality and LOS. DISCLOSURES: No relevant relationships by Seung Ick Cha, source=Web Response No relevant relationships by Hyewon Seo, source=Web Response

Relationship between digestive tract colonization and subsequent ventilator-associated pneumonia related to ESBL-producing Enterobacteriaceae

BackgroundVentilator-associated pneumonia (VAP) is the most common ICU-acquired infection. Recently, the incidence of extended-spectrum beta-lactamase producing Enterobacteriaceae (ESBLE) has substantially increased in critically ill patients. Identifying patients at risk for VAP related to ESBLE could be helpful to improve the rate of appropriate initial antibiotic treatment, and to reduce unnecessary exposure to carbapenems. The primary objective was to identify risk factors for VAP related to ESBLE. Secondary objective was to determine the impact of ESBLE on outcome in VAP patients.MethodsThis retrospective study was conducted in a single mixed intensive care unit (ICU), during a 4-year period. All patients with confirmed VAP were included. VAP was defined using clinical, radiologic and quantitative microbiological data. VAP first episodes were prospectively identified using the continuous surveillance data. Exposure to different risk factors was taken into account until the diagnosis of ESBLE VAP or until ICU discharge, in patients with ESBLE VAP and VAP related to other bacteria, respectively. In all patients, routine screening for ESBLE (rectal swab) was performed at ICU admission and once a week. Patients with ESBLE VAP were compared with those with VAP related to other bacteria using univariate analysis. All significant factors were included in the multivariate logistic regression model.ResultsAmong the 410 patients with VAP, 43 (10.5%) had ESBLE VAP, 76 (19%) patients had polymicrobial VAP and 189 (46%) had VAP related to multidrug resistant bacteria. Multivariate analysis identified prior ESBLE colonization of the digestive tract as the only independent risk factor for ESBLE VAP (OR [95% CI] = 23 [10–55], p < 0.001). Whilst the positive predictive value of ESBLE digestive colonization was low (43.6%), its negative predictive value was excellent (97.3%) in predicting ESBLE VAP. Duration of mechanical ventilation (median [IQR], 28 [18,42] vs 23 [15,42] d, p = 0.4), length of ICU stay (31 [19,53] vs 29 [18,46] d, p = 0.6), and mortality rates (55.8% vs 50%, p = 0.48) were similar in ESBLE VAP, compared with VAP related to other bacteria.ConclusionDigestive tract colonization related to ESBLE is independently associated with ESBLE VAP. Its excellent negative predictive value suggests that patients without ESBLE colonization should not receive carbapenems as part of their initial empirical treatment to cover ESBLE.

Infections with the agent of ‘kennel cough’ in patients with cancer

To investigate the clinical manifestations, microbiological data, and outcomes of Bordetella bronchiseptica (Bb) infections in patients with cancer. Review of electronic medical records of 24 patients with Bb infection, from 2000 to 2013. An infection was considered to be associated with Bb if both clinical manifestations plus microbial growth from infected sites were present. Ten patients (42%) had a monomicrobial infection, whereas multiple pathogens in addition to Bb were isolated from the rest (14 patients, 58%). The most frequent sites of infection were the respiratory tract (18 patients, 75 %) and bloodstream (17%). The most frequently associated conditions were lymphopenia (71%), tobacco use (42%), and chemotherapeutic or immunosuppressive agents (33% each). Animal exposure was established in four patients. Overall, the response rate to treatment was 100% for monomicrobial and 79% for polymicrobial infections, respectively. Bb is an uncommon pathogen even in immunosuppressed patients. Predominant sites of infection are the respiratory tract and bloodstream. Bb should be considered pathogenic in immunocompromised hosts, particularly with history of zoonotic exposure, even if accompanied by co-pathogens. Therefore, contact with potential animal sources should be minimized. The infection ranges from mild to severe and has no specific clinical or radiographic manifestations.

Relationship Between Clinical Features and Computed Tomographic Findings in Hospitalized Adult Patients With Community-Acquired Pneumonia

BackgroundData on the relationship between the clinical and microbiological features of community-acquired pneumonia (CAP) and its computed tomography (CT) findings are limited. The aim of the present study was to investigate the clinic-microbiological features of patients with CAP presenting with ground-glass opacity (GGO) and centrilobular nodules or tree-in-bud pattern on CT images. MethodsPatients with CAP who underwent a CT scan at presentation were retrospectively classified using CT findings into consolidation, GGO and bronchiolitis groups. These 3 groups were compared in terms of clinical parameters and microbiological data. ResultsA total of 40 patients (2.4%) were allocated to the bronchiolitis group and 46 (2.8%) to the GGO group. The most common pathogen in the bronchiolitis group was Mycoplasma pneumoniae, which was significantly more frequently isolated in this group. The bronchiolitis group was characterized by a higher percentage of cough, a lower percentage of chest pain and lower blood levels of inflammatory markers. Common pathogens in the GGO group were not significantly different from those in the other 2 groups. Unlike that observed in the consolidation group, complicated parapneumonic effusion or empyema was not observed in the bronchiolitis or GGO group. Outcome variables were similar in the 3 groups. ConclusionsThe bronchiolitis group was characterized by a higher frequency of M. pneumoniae and a less severe form of CAP. The GGO and consolidation groups was similar with respect to causative microorganisms and the clinical features of CAP. No patient in the bronchiolitis or GGO group exhibited complicated parapneumonic effusion or empyema.

Feline leprosy due to Candidatus 'Mycobacterium lepraefelis': Further clinical and molecular characterisation of eight previously reported cases and an additional 30 cases.

This paper, the last in a series of three on 'feline leprosy', provides a detailed description of disease referable to the previously unnamed species, Candidatus 'Mycobacterium lepraefelis', a close relative of the human pathogens Mycobacterium leprae and Mycobacterium lepromatosis. Cases were sourced retrospectively and prospectively for this observational study, describing clinical, geographical and molecular microbiological data for cats definitively diagnosed with Candidatus 'M lepraefelis' infection. A total of 145 cases of feline leprosy were scrutinised; 114 'new' cases were sourced from the Victorian Infectious Diseases Reference Laboratory (VIDRL) records, veterinary pathology laboratories or veterinarians, and 31 cases were derived from six published studies. Thirty-eight cats were definitively diagnosed with Candidatus 'M lepraefelis' infection. Typically, cats tended to be middle-aged or older when first infected, with a male predilection. Affected cats typically had widespread cutaneous lesions, in some cases after initially localised disease. Advanced cases were often systemically unwell. All cats had outdoor access. The histological picture was lepromatous in the majority of patients, although two cases had tuberculoid disease. In one case that underwent necropsy, lesions were evident in the liver, spleen and lungs. Treatment was varied, although most cats received a combination of oral clarithromycin and rifampicin. Prognosis for recovery was variable, but typically poor. Candidatus 'M lepraefelis' typically causes high bacterial index (lepromatous) feline leprosy that in some cases progresses to systemic mycobacteriosis. The disease has a variable clinical course and prognosis. Many cases either died or were euthanased due to the infection. Multilocus sequence analysis reveals a heterogeneous picture and further analysis of draft genome sequencing may give clues to the taxonomy and epidemiology of this organism. Prospective treatment trials and/or additional drug susceptibility testing in specialised systems would further inform treatment recommendations. Comparative aspects: This paper finishes with a discussion of comparative aspects of infection caused by the three feline leproid disease agents that have been the subject of this series: Candidatus 'Mycobacterium tarwinense', Mycobacterium lepraemurium and Candidatus 'M lepraefelis'.

Integration of DPC and clinical microbiological data in Japan reveals importance of confirming a negative follow-up blood culture in patients with MRSA bacteremia.

Methicillin-resistant Staphylococcus aureus (MRSA) bacteremia is one of the commonest and most life-threatening of all infectious diseases. The morbidity and mortality rates associated with MRSA bacteremia are higher than those associated with bacteremia caused by other pathogens. A common guideline in MRSA bacteremia treatment is to confirm bacteremia clearance through additional blood cultures 2-4 days after initial positive cultures and as needed thereafter. However, no study has presented statistical evidence of how and to what extent confirming a negative follow-up blood culture impacts clinical outcome. We present this evidence for the first time, by combining clinical microbiological data of blood cultures and the DPC administrative claims database; both had been systematically accumulated through routine medical care in hospitals. We used electronic medical records to investigate the clinical background and infection source in detail. By analyzing data from a university hospital, we revealed how survival curves change when a negative follow-up blood culture is confirmed. We also demonstrated confirmation of a negative culture is significantly associated with clinical outcomes: there was a more than three-fold increase in mortality risk (after adjusting for clinical background) if a negative blood culture was not confirmed within 14 days of the initial positive blood culture. Although we used data from only one university hospital, our novel approach and results will be a basis for future studies in several hospitals in Japan to provide statistical evidence of the clinical importance of confirming a negative follow-up blood culture in bacteremia patients, including those with MRSA infections.

Predictive factors for a one-year improvement in nontuberculous mycobacterial pulmonary disease: An 11-year retrospective and multicenter study.

BackgroundNontuberculous mycobacterial pulmonary disease (NTM-PD) has become an emerging infectious disease and is responsible for more deaths than tuberculosis in industrialized countries. NTM-PD mortality remains high in some series reportedly ranging from 25% to 40% at five years and often due to unfavorable evolution of NTM-PD despite established treatment. The purpose of our study was to search for early factors that could predict the favorable or unfavorable evolution of NTM-PD at the first year of treatment.MethodsIn this retrospective and multicenter study, we selected 119 patients based on clinical, radiological and microbiological data from 2002 to 2012 from three French university hospitals (Guadeloupe, Martinique, Montpellier) with definite (meeting the criteria of the American Thoracic Society and the Infectious Disease Society of America in 2007; ATS/IDSA) or probable (one positive sputum culture) NTM-PD. We compared two patient groups: those who improved at one year (clinical symptoms, radiological lesions and microbiology data) and those who did not improve at one year. The data were analyzed for all patients as well as for subgroups by gender, HIV-positive patients, and Mycobacterium avium complex (MAC) infection.ResultsThe average patient age was 50 years ± 19.4; 58% had respiratory comorbidities, 24% were HIV positive and 19% had cystic fibrosis. Coughing concerned 66% of patients and bronchiectasis concerned 45%. The most frequently isolated NTM were MAC (46%). 57% (n = 68) of patients met the ATS criteria and improved status concerned 38.6% (n = 46). The improvement factors at one year of NTM-PD were associated with the duration of ethambutol treatment: (Odds ratio adjusted [ORa]: 2.24, 95% Confidence interval [CI]; 2.11–3.41), HIV-positive status: (ORa: 3.23, 95% CI; 1.27–8.45), and male gender: (ORa: 2.34, 95% CI; 1.26–8.16). For the group with NTM-PD due to MAC, improvement was associated with the duration of macrolide treatment (ORa: 3.27, 95% CI; 1.88–7.30) and an age <50 years (ORa: 1.88, 95% CI; 1.55–8.50).ConclusionIn this retrospective multicenter study, improvement at one year in patients with definite or probable NTM-PD was associated with the duration of ethambutol treatment, HIV-positive status and male gender. For the group of patients infected with MAC, improvement was associated with the duration of macrolide treatment and an age <50 years. Identifying predictors of improvement at one year of NTM-PD is expected to optimize the management of the disease in its early stages.

Evaluating the Clinical Burden and Mortality Attributable to Antibiotic Resistance: The Disparity of Empirical Data and Simple Model Estimations.

Given the proliferation of cataclysmic predictions about antibiotic resistance, cases of which are estimated to amount to 12500 per year in France, we herein decided to compare the empirical clinical microbiology data from our institution with estimates and predictions from 10 major international scientific articles and reports. The analysis of 7 years of antibiotic resistance data from 10 bacterial species and genera of clinical interest from our institution identified no deaths that were directly attributable to extremely drug-resistant bacteria. By comparing our observations to the 10 articles and reports studied herein, we concluded that their results lack empirical data. Interventions are urgently needed to significantly reduce both mortality and the healthcare costs associated with bacterial infections, including the implementation of local and national laboratory data-based surveillance systems for the routine surveillance of antibiotic resistance that would be helpful for a better understanding of how to manage antibiotic-resistant bacteria in the future.

Feline leprosy due to Mycobacterium lepraemurium.

This paper, the second in a series of three on 'feline leprosy', provides a detailed description of disease referable to Mycobacterium lepraemurium, the most common cause of feline leprosy worldwide. Cases were sourced retrospectively and prospectively for this observational study, describing clinical, geographical and molecular microbiological data for cats definitively diagnosed with M lepraemurium infection. A total of 145 cases of feline leprosy were scrutinised; 114 'new' cases were sourced from the Victorian Infectious Diseases Reference Laboratory records, veterinary pathology laboratories or veterinarians, and 31 cases were derived from six published studies. Sixty-five cats were definitively diagnosed with M lepraemurium infection. Typically, cats were 1-3 years of age when first infected, with a male gender predilection. Affected cats were generally systemically well. All had outdoor access. Lesions tended to consist of one or more cutaneous/subcutaneous nodules, typically located on the head and/or forelimbs, possibly reflecting the most likely locations for a rodent bite as the site of inoculation for organisms. Nodules had the propensity to ulcerate at some stage in the clinical course. The cytological and histological picture varied from tuberculoid, with relatively low bacterial numbers, to lepromatous with moderate to high bacterial numbers. Treatment was varied, although most cats underwent surgical resection of lesions with adjunctive medical therapy, most often using a combination of oral clarithromycin and rifampicin. Prognosis for recovery was generally good, and in two cases there was spontaneous remission without the requirement for medical intervention. Untreated cats continued to enjoy an acceptable quality of life despite persistence of the disease, which extended locally but had no apparent tendency to disseminate to internal organs. M lepraemurium causes high bacterial index (lepromatous) or low bacterial index (tuberculoid) feline leprosy. The infection typically causes nodules of the skin and/or subcutis (which tend towards ulceration) on the head and/or forelimbs. The disease usually has an indolent clinical course and infected cats have a generally favourable response to therapeutic interventions, with rare cases undergoing spontaneous resolution. Genomic analysis may yield clues as to the environmental niche and culture requirements of this elusive organism. Prospective treatment trials and/or additional drug susceptibility testing in specialised systems would further inform treatment recommendations.

Implementation of a systematic culturing program to monitor the efficacy of endoscope reprocessing: outcomes and costs

In 2015, the U.S. Food and Drug Administration and Centers for Disease Control and Prevention (CDC) issued guidance for duodenoscope culturing and reprocessing in response to outbreaks of carbapenem-resistant Enterobacteriaceae (CRE) duodenoscope-related infections. Based on this guidance, we implemented best practices for reprocessing and developed a systematic process for culturing endoscopes with elevator levers. The aim of this study is to report the outcomes and direct costs of this program. First, clinical microbiology data from 2011 to 2014 were reviewed retrospectively to assess for possible elevator lever-equipped endoscope-related CRE infections. Second, a program to systematically culture elevator lever-equipped endoscopes was implemented. Each week, about 25% of the inventory of elevator lever-equipped endoscopes is cultured based on the CDC guidelines. If any cultures return bacterial growth, the endoscope is quarantined pending repeat culturing. The costs of the program, including staff time and supplies, have been calculated. From 2011 to 2014, none of 17 patients with documented CRE infection had undergone ERCP or endoscopic ultrasound in the previous 36 months. From June 2015 to September 2016, 285 cultures were performed. Three (1.1%) had bacterial growth, 2 with skin contaminants and 1 with an oral contaminant. The associated endoscopes were quarantined and reprocessed, and repeat cultures were negative. The total estimated cost of our program for an inventory of 20 elevator lever-equipped endoscopes was $30,429.60 per year ($1521.48 per endoscope). This 16-month evaluation of a systematic endoscope culturing program identified a low rate of positive cultures after elevator lever endoscope reprocessing. All positive cultures were with non-enteric microorganisms. The program was of modest cost and identified reprocessing procedures that may have led to a low rate of positive cultures.

Feline leprosy due to Candidatus 'Mycobacterium tarwinense':Further clinical and molecular characterisation of 15 previously reported cases and an additional 27 cases

This paper, the first in a series of three on 'feline leprosy', provides a detailed description of disease referable to Candidatus 'Mycobacterium tarwinense', the most common cause of feline leprosy in Victoria, Australia. Cases were sourced retrospectively and prospectively for this observational study, describing clinical, geographical and molecular microbiological data for cats definitively diagnosed with Candidatus 'M tarwinense' infection. A total of 145 cases of feline leprosy were scrutinised; 114 'new' cases were sourced from the Victorian Infectious Diseases Reference Laboratory records, veterinary pathology laboratories or veterinarians, and 31 cases were derived from six published studies. Forty-two cats were definitively diagnosed with Candidatus 'M tarwinense' infection. Typically, cats were between 3 and 11 years of age, with no gender predilection, and were generally systemically well. All had outdoor access. Most cats underwent surgical resection of lesions with adjunctive medical therapy, often utilising a combination of oral clarithromycin and rifampicin for at least 3 months. Prognosis for recovery was generally good. Resolution of lesions was not observed in the absence of treatment, but a number of untreated cats continued to enjoy an acceptable quality of life despite persistence of the disease, which extended locally but did not appear to disseminate to internal organs. Preliminary results of draft genome sequencing confirmed that the species is a member of the Mycobacterium simiae complex. Candidatus 'M tarwinense', a fastidious member of the M simiae complex, is capable of causing feline leprosy with a tendency to produce lesions on the head, particularly involving the eyes and periocular skin. The disease has an indolent clinical course and generally responds favourably to therapy despite lesions often containing large numbers of organisms. Detailed genomic analysis may yield clues as to the environmental niche and culture requirement of this elusive organism. Prospective treatment trials and/or drug susceptibility testing in specialised systems would further inform treatment recommendations.

Risk factors for mortality in children with pneumonia admitted to the pediatric intensive care unit.

To describe the epidemiology of children with severe pneumonia and identify risk factors for poor outcomes. We conducted a retrospective study of children admitted to pediatric intensive care unit (PICU) from 2010 to 2014 with a diagnosis of pneumonia. Clinical microbiological, ventilation and other pertinent PICU data were collected. Primary outcome was PICU mortality. Univariate and multivariate logistic regression model were used to identify risk factors for mortality. Severe pneumonia consisted of 237/3539 (6.7%) of PICU admissions. Of these, 162/237 (68.4%) required mechanical ventilation. 32/237 (13.5%) patients died. The majority of patients had no organisms identified 82/237 (34.6%). A sole bacterial or viral pathogen was identified in 48/237 (20.1%) and 41/237 (17.9%) patients, respectively. Patients with viral pneumonias were more likely to develop acute respiratory distress syndrome compared to other etiologies (7/41[17.1%] vs 8/196 [4.0%]; P = 0.006). Bacterial pneumonias were associated with lung abscess (4/48 [8.3%] vs 2/189 [1.5%]; P = 0.016) and necrotizing pneumonia (18/48 [37.5%] vs 15/189 [7.9%]; P < 0.001) compared to other etiologies. Co-detections (>1 respiratory pathogens isolated) occurred in 62/237 (26.2%) patients and were associated a higher rate of mechanical ventilation, and decreased ventilator and PICU free days. After adjusting for severity of illness, risk factors for mortality were: hospital acquired pneumonia (HAP) (aOR: 2.92 [95%CI 1.15, 7.40]; P = 0.024) and bacteremia (aOR: 5.03 [95%CI 1.77, 14.35]; P = 0.003). Severe pediatric pneumonia accounts for a significant number of PICU admissions and is associated with significant mortality risk. The presence of co-morbidities, HAP and bacteremia were early prognostic variables independently associated with poor clinical outcomes.

Enhancing the Utility of Antibiotic Susceptibility Reporting as a Tool for Antimicrobial Stewardship

Hospital antibiograms are a method for presenting cumulative antibiotic susceptibility data using routinely collected clinical microbiology data. They provide critical foundational knowledge to inform development of antimicrobial stewardship program (ASP) strategies but are also provided to clinicians to inform empiric antibiotic therapy selection. Earlier research has demonstrated that use of the antibiogram to direct prudent antibiotic selection is less than desired. Use by non-infectious disease practitioners has been limited, and antibiotic prescribing has not aligned with ASP goals. Over the past 5 years, newer research has emerged to increase the utility of the antibiogram through education, stratification, and cross-tabulation of data for combination therapy. These approaches focus on increasing use of the cumulative antibiogram and ensuring that the data appropriately influence the antibiotic therapy selection. Data available to date suggest that these strategies can be effective methods of increasing use of concordant and relatively narrow spectrum empiric antibiotic regimens.

Campylobacter bacteraemia: 16 years of experience in a single centre

Background: Campylobacter bacteraemia (CB) is rare and usually occurs in immune-compromised patients. In this study we examined the incidence and epidemiology of CB in one institution over 15.5 years.Methods: The medical records of all the consecutive patients with CB admitted to our hospital from 2000 to 2015 were retrospectively reviewed. Clinical characteristics, microbiologic and outcome data were collected.Results: During the study period, 65 patients with CB were identified. The majority of the patients were middle aged and immune-compromised. Campylobacter jejuni was the most commonly identified species (33/47, 70%). The main underlying conditions were haematological malignancies (43%) and chronic liver disease (14%). Fifty-seven percent of the patients were receiving immunosuppressive therapy at the time of bacteraemia. The most common presenting symptoms were fever (85%), diarrhoea (40%), abdominal pain (40%), and nausea and vomiting (40%). Of the isolates tested, 97% were susceptible to macrolides, and only 35% were susceptible to quinolones. Susceptibility to quinolones decreased over the years. Most patients did not receive adequate empiric antibiotic treatment (81.5%) and about 20% never received directed therapy. Mortality and relapse rates were low (5% each). There was no association between adequate empirical or definitive antibiotic therapy and adverse outcomes.Conclusion: The main predisposing factor for Campylobacter bacteraemia in our cohort was immunosuppression. Prognosis was generally favourable regardless of appropriateness of antibiotic therapy.