RESUMEN
BACKGROUND: Multiresistant organisms (MROs) pose a critical threat to public health. Population-based programs for control of MROs such as carbapenemase-producing Enterobacterales (CPE) have emerged and evaluation is needed. We assessed the feasibility and impact of a statewide CPE surveillance and response program deployed across Victoria, Australia (population 6.5 million). METHODS: A prospective multimodal intervention including active screening, carrier isolation, centralized case investigation, and comparative pathogen genomics was implemented. We analyzed trends in CPE incidence and clinical presentation, risk factors, and local transmission over the program's first 3 years (2016-2018). RESULTS: CPE case ascertainment increased over the study period to 1.42 cases/100â 000 population, linked to increased screening without a concomitant rise in active clinical infections (0.45-0.60 infections/100â 000 population, Pâ =â .640). KPC-2 infection decreased from 0.29 infections/100â 000 population prior to intervention to 0.03 infections/100â 000 population in 2018 (Pâ =â .003). Comprehensive case investigation identified instances of overseas community acquisition. Median time between isolate referral and genomic and epidemiological assessment for local transmission was 11 days (IQR, 9-14). Prospective surveillance identified numerous small transmission networks (median, 2; range, 1-19 cases), predominantly IMP and KPC, with median pairwise distance of 8 (IQR, 4-13) single nucleotide polymorphisms; low diversity between clusters of the same sequence type suggested genomic cluster definitions alone are insufficient for targeted response. CONCLUSIONS: We demonstrate the value of centralized CPE control programs to increase case ascertainment, resolve risk factors, and identify local transmission through prospective genomic and epidemiological surveillance; methodologies are transferable to low-prevalence settings and MROs globally.
Asunto(s)
Infecciones por Enterobacteriaceae , Proteínas Bacterianas/genética , Infecciones por Enterobacteriaceae/epidemiología , Infecciones por Enterobacteriaceae/prevención & control , Genómica , Humanos , Estudios Prospectivos , Victoria , beta-Lactamasas/genéticaRESUMEN
BACKGROUND: Third-generation cephalosporin-resistant Gram-negatives (3GCR-GN) and vancomycin-resistant enterococci (VRE) are common causes of multi-drug resistant healthcare-associated infections, for which gut colonisation is considered a prerequisite. However, there remains a key knowledge gap about colonisation and infection dynamics in high-risk settings such as the intensive care unit (ICU), thus hampering infection prevention efforts. METHODS: We performed a three-month prospective genomic survey of infecting and gut-colonising 3GCR-GN and VRE among patients admitted to an Australian ICU. Bacteria were isolated from rectal swabs (n = 287 and n = 103 patients ≤2 and > 2 days from admission, respectively) and diagnostic clinical specimens between Dec 2013 and March 2014. Isolates were subjected to Illumina whole-genome sequencing (n = 127 3GCR-GN, n = 41 VRE). Multi-locus sequence types (STs) and antimicrobial resistance determinants were identified from de novo assemblies. Twenty-three isolates were selected for sequencing on the Oxford Nanopore MinION device to generate completed reference genomes (one for each ST isolated from ≥2 patients). Single nucleotide variants (SNVs) were identified by read mapping and variant calling against these references. RESULTS: Among 287 patients screened on admission, 17.4 and 8.4% were colonised by 3GCR-GN and VRE, respectively. Escherichia coli was the most common species (n = 36 episodes, 58.1%) and the most common cause of 3GCR-GN infection. Only two VRE infections were identified. The rate of infection among patients colonised with E. coli was low, but higher than those who were not colonised on admission (n = 2/33, 6% vs n = 4/254, 2%, respectively, p = 0.3). While few patients were colonised with 3GCR- Klebsiella pneumoniae or Pseudomonas aeruginosa on admission (n = 4), all such patients developed infections with the colonising strain. Genomic analyses revealed 10 putative nosocomial transmission clusters (≤20 SNVs for 3GCR-GN, ≤3 SNVs for VRE): four VRE, six 3GCR-GN, with epidemiologically linked clusters accounting for 21 and 6% of episodes, respectively (OR 4.3, p = 0.02). CONCLUSIONS: 3GCR-E. coli and VRE were the most common gut colonisers. E. coli was the most common cause of 3GCR-GN infection, but other 3GCR-GN species showed greater risk for infection in colonised patients. Larger studies are warranted to elucidate the relative risks of different colonisers and guide the use of screening in ICU infection control.
Asunto(s)
Infección Hospitalaria , Farmacorresistencia Bacteriana Múltiple/genética , Escherichia coli , Tracto Gastrointestinal/microbiología , Control de Infecciones , Unidades de Cuidados Intensivos , Enterococos Resistentes a la Vancomicina , Antibacterianos/farmacología , Australia/epidemiología , Resistencia a las Cefalosporinas/genética , Infección Hospitalaria/epidemiología , Infección Hospitalaria/microbiología , Infección Hospitalaria/prevención & control , Escherichia coli/genética , Escherichia coli/aislamiento & purificación , Escherichia coli/patogenicidad , Humanos , Control de Infecciones/métodos , Control de Infecciones/normas , Unidades de Cuidados Intensivos/normas , Unidades de Cuidados Intensivos/estadística & datos numéricos , Estudios Prospectivos , Enterococos Resistentes a la Vancomicina/genética , Enterococos Resistentes a la Vancomicina/aislamiento & purificaciónRESUMEN
Coagulase-negative staphylococci (CoNS) represent one of the major causes of health care- and medical device-associated infections. Emerging antimicrobial resistance has complicated the treatment of systemic infections caused by CoNS. Here, we describe the prevalence of antimicrobial resistance in clinical CoNS strains from a tertiary care hospital over a 4-year period, and we observed a significant increase in resistance to daptomycin. Notably, Staphylococcus capitis accounted for the majority of these daptomycin-resistant (DAP-R) CoNS. To further investigate the mechanisms of daptomycin resistance in CoNS, daptomycin-susceptible clinical strains of S. capitis and Staphylococcus epidermidis underwent in vitro daptomycin exposure to generate DAP-R CoNS mutants. Unlike that seen with Staphylococcus aureus, alteration of cell surface charge was not observed in the DAP-R CoNS strains, but biofilm formation was compromised. Whole-genome sequencing analysis of the DAP-R CoNS strains identified single nucleotide polymorphisms (SNPs) in walKR, the essential two-component regulatory system controlling cell wall biogenesis. PCR and sequencing of walK and walR from 17 DAP-R CoNS clinical isolates identified seven nonsynonymous mutations. The results were confirmed by the recreation of the walK SNP in S. epidermidis, which resulted in reduced susceptibility to daptomycin and vancomycin. This study highlights the significance of CoNS in evolving daptomycin resistance and showed that walKR is shared among the staphylococcal species and is involved in antibiotic resistance development. Notably, we did not observe mutations in genes responsible for phospholipid biosynthesis or an altered cell surface charge, suggesting that reduced daptomycin susceptibility in CoNS may emerge in a fashion distinct from that in S. aureus.
Asunto(s)
Antibacterianos/farmacología , Daptomicina/farmacología , Farmacorresistencia Bacteriana/genética , Staphylococcus capitis/genética , Staphylococcus epidermidis/genética , Sustitución de Aminoácidos/genética , Proteínas Bacterianas/genética , Biopelículas/crecimiento & desarrollo , Infección Hospitalaria/microbiología , Histidina Quinasa/genética , Humanos , Pruebas de Sensibilidad Microbiana , Polimorfismo de Nucleótido Simple/genética , Infecciones Estafilocócicas/tratamiento farmacológico , Staphylococcus aureus/efectos de los fármacos , Staphylococcus capitis/efectos de los fármacos , Staphylococcus capitis/aislamiento & purificación , Staphylococcus epidermidis/efectos de los fármacos , Staphylococcus epidermidis/aislamiento & purificación , Centros de Atención Terciaria , Vancomicina/farmacologíaRESUMEN
Background: Klebsiella pneumoniae is a leading cause of extended-spectrum ß-lactamase (ESBL)-producing hospital-associated infections, for which elderly patients are at increased risk. Methods: We conducted a 1-year prospective cohort study, in which a third of patients admitted to 2 geriatric wards in a specialized hospital were recruited and screened for carriage of K. pneumoniae by microbiological culture. Clinical isolates were monitored via the hospital laboratory. Colonizing and clinical isolates were subjected to whole-genome sequencing and antimicrobial susceptibility testing. Results: K. pneumoniae throat carriage prevalence was 4.1%, rectal carriage 10.8%, and ESBL carriage 1.7%, and the incidence of K. pneumoniae infection was 1.2%. The isolates were diverse, and most patients were colonized or infected with a unique phylogenetic lineage, with no evidence of transmission in the wards. ESBL strains carried blaCTX-M-15 and belonged to clones associated with hospital-acquired ESBL infections in other countries (sequence type [ST] 29, ST323, and ST340). One also carried the carbapenemase blaIMP-26. Genomic and epidemiological data provided evidence that ESBL strains were acquired in the referring hospital. Nanopore sequencing also identified strain-to-strain transmission of a blaCTX-M-15 FIBK/FIIK plasmid in the referring hospital. Conclusions: The data suggest the major source of K. pneumoniae was the patient's own gut microbiome, but ESBL strains were acquired in the referring hospital. This highlights the importance of the wider hospital network to understanding K. pneumoniae risk and infection prevention. Rectal screening for ESBL organisms on admission to geriatric wards could help inform patient management and infection control in such facilities.
Asunto(s)
Portador Sano/microbiología , Infección Hospitalaria/microbiología , Farmacorresistencia Bacteriana Múltiple , Klebsiella pneumoniae/aislamiento & purificación , Anciano , Anciano de 80 o más Años , Infección Hospitalaria/diagnóstico , Femenino , Servicios de Salud para Ancianos , Unidades Hospitalarias , Humanos , Infecciones por Klebsiella/tratamiento farmacológico , Klebsiella pneumoniae/efectos de los fármacos , Masculino , Persona de Mediana Edad , Estudios ProspectivosRESUMEN
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.
Asunto(s)
Manejo de la Enfermedad , Neurosífilis/diagnóstico , Neurosífilis/terapia , Treponema pallidum/aislamiento & purificación , Australasia/epidemiología , Pruebas Diagnósticas de Rutina/métodos , Humanos , Neurosífilis/epidemiología , Serodiagnóstico de la Sífilis/métodos , Factores de TiempoRESUMEN
BACKGROUND: Klebsiella pneumoniae is an opportunistic pathogen and leading cause of hospital-associated infections. Intensive care unit (ICU) patients are particularly at risk. Klebsiella pneumoniae is part of the healthy human microbiome, providing a potential reservoir for infection. However, the frequency of gut colonization and its contribution to infections are not well characterized. METHODS: We conducted a 1-year prospective cohort study in which 498 ICU patients were screened for rectal and throat carriage of K. pneumoniae shortly after admission. Klebsiella pneumoniae isolated from screening swabs and clinical diagnostic samples were characterized using whole genome sequencing and combined with epidemiological data to identify likely transmission events. RESULTS: Klebsiella pneumoniae carriage frequencies were estimated at 6% (95% confidence interval [CI], 3%-8%) among ICU patients admitted direct from the community, and 19% (95% CI, 14%-51%) among those with recent healthcare contact. Gut colonization on admission was significantly associated with subsequent infection (infection risk 16% vs 3%, odds ratio [OR] = 6.9, P < .001), and genome data indicated matching carriage and infection isolates in 80% of isolate pairs. Five likely transmission chains were identified, responsible for 12% of K. pneumoniae infections in ICU. In sum, 49% of K. pneumoniae infections were caused by the patients' own unique strain, and 48% of screened patients with infections were positive for prior colonization. CONCLUSIONS: These data confirm K. pneumoniae colonization is a significant risk factor for infection in ICU, and indicate ~50% of K. pneumoniae infections result from patients' own microbiota. Screening for colonization on admission could limit risk of infection in the colonized patient and others.
Asunto(s)
Portador Sano/epidemiología , Infección Hospitalaria/microbiología , Microbioma Gastrointestinal , Tracto Gastrointestinal/microbiología , Unidades de Cuidados Intensivos , Infecciones por Klebsiella/microbiología , Klebsiella pneumoniae/aislamiento & purificación , Adulto , Anciano , Antibacterianos/farmacología , Portador Sano/tratamiento farmacológico , Portador Sano/microbiología , Estudios de Cohortes , Infección Hospitalaria/epidemiología , Femenino , Variación Genética , Humanos , Infecciones por Klebsiella/tratamiento farmacológico , Infecciones por Klebsiella/epidemiología , Infecciones por Klebsiella/transmisión , Klebsiella pneumoniae/efectos de los fármacos , Klebsiella pneumoniae/genética , Masculino , Pruebas de Sensibilidad Microbiana , Persona de Mediana Edad , Faringe/microbiología , Estudios Prospectivos , Recto/microbiología , Factores de RiesgoRESUMEN
In recent decades, sporotrichosis, caused by thermally dimorphic fungi Sporothrix schenckii complex, has become an emerging infection in many parts of the world. Pulmonary infection with S. schenckii still remains relatively uncommon, possibly due to underrecognition. Pulmonary sporotrichosis presents with distinct clinical and radiological patterns in both immunocompetent and immunocompromised hosts and can often result in significant morbidity and mortality despite treatment. Current understanding regarding S. schenckii biology, epidemiology, immunopathology, clinical diagnostics, and treatment options has been evolving in the recent years with increased availability of molecular sequencing techniques. However, this changing knowledge has not yet been fully translated into a better understanding of the clinical aspects of pulmonary sporotrichosis, as such current management guidelines remain unsupported by high-level clinical evidence. This article examines recent advances in the knowledge of sporotrichosis and its application to the difficult challenges of managing pulmonary sporotrichosis.
Asunto(s)
Antifúngicos/uso terapéutico , Enfermedades Pulmonares Fúngicas/microbiología , Sporothrix , Esporotricosis/diagnóstico , Esporotricosis/epidemiología , Manejo de la Enfermedad , Humanos , Huésped Inmunocomprometido , Enfermedades Pulmonares Fúngicas/diagnóstico por imagen , Radiografía , Factores de RiesgoAsunto(s)
Prueba de Ácido Nucleico para COVID-19/métodos , COVID-19/diagnóstico , Hospitalización , Anciano , COVID-19/epidemiología , COVID-19/metabolismo , Prueba de Ácido Nucleico para COVID-19/tendencias , Prueba de COVID-19/métodos , Prueba de COVID-19/tendencias , Pruebas Diagnósticas de Rutina/métodos , Pruebas Diagnósticas de Rutina/tendencias , Femenino , Hospitalización/tendencias , Humanos , Incidencia , Masculino , Persona de Mediana Edad , Estudios RetrospectivosRESUMEN
BACKGROUND: Ventricular assist device (VAD) implantation has become an effective option for patients with severe heart failure. However, device-related infections remain a significant problem. The aim of this study was to describe the incidence and microbiological aetiology of bacteraemia in patients with VADs, and to assess the impact of bacteraemia on clinical outcomes. METHODS: A retrospective study was conducted of patients having VAD implantation at the Alfred Hospital (Melbourne, Australia) from October 1990 to July 2009. Medical records and microbiology databases were reviewed. Patients who were supported with a VAD for 72h or more were evaluated for demographic data, VAD type, the occurrence of bacteraemia and clinical outcomes. RESULTS: During the 19-year period, 135 VAD patients (89 Thoratec PVAD, 10 Novacor, and 36 Ventrassist) supported for a total duration of 17,304 (median 74) support days were included. Sixty-one patients (45%) developed VAD-associated bacteraemia, an incidence of 5.6 episodes per 1000 support days. The incidence of bacteraemia per 1000 days of support was similar for the three devices used: Thoratec PVAD, Novacor and Ventrassist VADs (7.8±0.8, 5.2±1.5 and 3.4±0.5, respectively, p=0.74). Staphylococcus aureus was the most common pathogen (25%). The rates of death on device, survival to transplant, recovery with explant and outcomes after transplantation, including 30-day mortality, median survival time and incidence of cerebrovascular accidents were not significantly impacted upon by bacteraemia. CONCLUSIONS: Bacteraemia is common in VAD patients. However, the incidence of VAD-associated bacteraemia is independent of device type and with aggressive antimicrobial therapy; clinical outcomes need not be affected by the bacteraemia.
Asunto(s)
Antibacterianos/administración & dosificación , Bacteriemia , Corazón Auxiliar/efectos adversos , Registros Médicos , Infecciones Estafilocócicas , Staphylococcus aureus , Adolescente , Adulto , Anciano , Bacteriemia/tratamiento farmacológico , Bacteriemia/etiología , Bacteriemia/mortalidad , Supervivencia sin Enfermedad , Femenino , Humanos , Incidencia , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Infecciones Estafilocócicas/tratamiento farmacológico , Infecciones Estafilocócicas/etiología , Infecciones Estafilocócicas/mortalidad , Tasa de SupervivenciaRESUMEN
OBJECTIVES: New Delhi metallo-ß-lactamases (NDMs) are major contributors to the spread of carbapenem resistance globally. In Australia, NDMs were previously associated with international travel, but from 2019 we noted increasing incidence of NDM-positive clinical isolates. We investigated the clinical and genomic epidemiology of NDM carriage at a tertiary-care Australian hospital from 2016 to 2021. METHODS: We identified 49 patients with 84 NDM-carrying isolates in an institutional database, and we collected clinical data from electronic medical record. Short- and long-read whole genome sequencing was performed on all isolates. Completed genome assemblies were used to assess the genetic setting of blaNDM genes and to compare NDM plasmids. RESULTS: Of 49 patients, 38 (78%) were identified in 2019-2021 and only 11 (29%) of 38 reported prior travel, compared with 9 (82%) of 11 in 2016-2018 (P = .037). In patients with NDM infection, the crude 7-day mortality rate was 0% and the 30-day mortality rate was 14% (2 of 14 patients). NDMs were noted in 41 bacterial strains (ie, species and sequence type combinations). Across 13 plasmid groups, 4 NDM variants were detected: blaNDM-1, blaNDM-4, blaNDM-5, and blaNDM-7. We noted a change from a diverse NDM plasmid repertoire in 2016-2018 to the emergence of conserved blaNDM-1 IncN and blaNDM-7 IncX3 epidemic plasmids, with interstrain spread in 2019-2021. These plasmids were noted in 19 (50%) of 38 patients and 35 (51%) of 68 genomes in 2019-2021. CONCLUSIONS: Increased NDM case numbers were due to local circulation of 2 epidemic plasmids with extensive interstrain transfer. Our findings underscore the challenges of outbreak detection when horizontal transmission of plasmids is the primary mode of spread.
Asunto(s)
Brotes de Enfermedades , Plásmidos , beta-Lactamasas , Humanos , beta-Lactamasas/genética , Plásmidos/genética , Masculino , Femenino , Persona de Mediana Edad , Anciano , Australia/epidemiología , Secuenciación Completa del Genoma , Adulto , Infecciones por Enterobacteriaceae/epidemiología , Infecciones por Enterobacteriaceae/transmisión , Infecciones por Enterobacteriaceae/microbiología , Transferencia de Gen Horizontal , Anciano de 80 o más Años , Antibacterianos/farmacología , Antibacterianos/uso terapéutico , Genoma BacterianoRESUMEN
We collected 163 clinical Pseudomonas aeruginosa isolates at a tertiary hospital specialising in adult cystic fibrosis (CF) and lung transplantation (LTx) in Melbourne, Australia, to explore the activity of ceftolozane-tazobactam (C/T) in populations at high-risk for antimicrobial resistance. Of these, 144 (88.3%) were collected from sputum, and 19 (11.7%) from bronchoalveolar lavage. Most (85.3%) were derived from patients with cystic fibrosis and included a subset of patients that had undergone LTx. These isolates were tested against 11 antibiotics, including C/T, using Sensititre plates for broth microdilution (BMD) testing. Sixty (36.8%) isolates were classified as multidrug resistant (MDR) and 32 (19.6%) were extensively drug resistant (XDR). Overall, 133/163 (81.6%) isolates were susceptible to C/T. For MDR and XDR isolates, 88.3% and 28.1% were C/T susceptible, respectively. Among the non-MDR/XDR isolates, 100% remained susceptible to C/T. Comparisons of C/T susceptibility were made using BioMérieux Etests and Liofilchem MIC test strips (MTS). Categorical agreement to BMD was >93% for both test strips, but essential agreement to BMD was slightly higher with Etest (89.0%) compared to Liofilchem (74.8%). In conclusion, C/T retained activity against most MDR and over a quarter of XDR P. aeruginosa isolates from complex patients with CF and post-LTx.
Asunto(s)
Fibrosis Quística , Infecciones por Pseudomonas , Adulto , Humanos , Pseudomonas aeruginosa , Pruebas de Sensibilidad Microbiana , Farmacorresistencia Bacteriana Múltiple , Tazobactam/farmacología , Cefalosporinas/farmacología , Antibacterianos/farmacología , Australia , Infecciones por Pseudomonas/tratamiento farmacológicoRESUMEN
Infections caused by metallo-beta-lactamase-producing organisms (MBLs) are a global health threat. Our understanding of transmission dynamics and how MBLs establish endemicity remains limited. We analysed two decades of blaIMP-4 evolution in a hospital using sequence data from 270 clinical and environmental isolates (including 169 completed genomes) and identified the blaIMP-4 gene across 7 Gram-negative genera, 68 bacterial strains and 7 distinct plasmid types. We showed how an initial multi-species outbreak of conserved IncC plasmids (95 genomes across 37 strains) allowed endemicity to be established through the ability of blaIMP-4 to disseminate in successful strain-genetic setting pairs we termed propagators, in particular Serratia marcescens and Enterobacter hormaechei. From this reservoir, blaIMP-4 persisted through diversification of genetic settings that resulted from transfer of blaIMP-4 plasmids between bacterial hosts and of the integron carrying blaIMP-4 between plasmids. Our findings provide a framework for understanding endemicity and spread of MBLs and may have broader applicability to other carbapenemase-producing organisms.
Asunto(s)
Integrones , beta-Lactamasas , Integrones/genética , beta-Lactamasas/genética , beta-Lactamasas/metabolismo , Proteínas Bacterianas/genética , Plásmidos/genética , Serratia marcescens/genética , Serratia marcescens/metabolismo , Carbapenémicos/farmacología , Genómica , Pruebas de Sensibilidad Microbiana , Antibacterianos/farmacologíaRESUMEN
Klebsiella pneumoniae is a major cause of opportunistic healthcare-associated infections, which are increasingly complicated by the presence of extended-spectrum beta-lactamases (ESBLs) and carbapenem resistance. We conducted a year-long prospective surveillance study of K. pneumoniae clinical isolates in hospital patients. Whole-genome sequence (WGS) data reveals a diverse pathogen population, including other species within the K. pneumoniae species complex (18%). Several infections were caused by K. variicola/K. pneumoniae hybrids, one of which shows evidence of nosocomial transmission. A wide range of antimicrobial resistance (AMR) phenotypes are observed, and diverse genetic mechanisms identified (mainly plasmid-borne genes). ESBLs are correlated with presence of other acquired AMR genes (median n = 10). Bacterial genomic features associated with nosocomial onset are ESBLs (OR 2.34, p = 0.015) and rhamnose-positive capsules (OR 3.12, p < 0.001). Virulence plasmid-encoded features (aerobactin, hypermucoidy) are observed at low-prevalence (<3%), mostly in community-onset cases. WGS-confirmed nosocomial transmission is implicated in just 10% of cases, but strongly associated with ESBLs (OR 21, p < 1 × 10-11). We estimate 28% risk of onward nosocomial transmission for ESBL-positive strains vs 1.7% for ESBL-negative strains. These data indicate that K. pneumoniae infections in hospitalised patients are due largely to opportunistic infections with diverse strains, with an additional burden from nosocomially-transmitted AMR strains and community-acquired hypervirulent strains.
Asunto(s)
Infección Hospitalaria , Infecciones por Klebsiella , Infección Hospitalaria/epidemiología , Infección Hospitalaria/microbiología , Genómica , Hospitales , Humanos , Infecciones por Klebsiella/epidemiología , Infecciones por Klebsiella/microbiología , Klebsiella pneumoniae , Estudios ProspectivosRESUMEN
OBJECTIVES: Nocardia bacteremia is a rare but severe disease associated with high mortality. This systematic review is the largest and most comprehensive review performed over the past 20 years. METHODS: A single-center retrospective review of Nocardia bacteremia was performed using hospital microbiology records from January 1, 2010 to December 31, 2017. A systematic literature review was also performed to identify cases of Nocardia bacteremia described in the NCBI PubMed database in English between January 1, 1999 and December 31, 2018. RESULTS: Four new cases of Nocardia bacteremia are described. The systematic review identified 134 cases with sufficient information available for analysis. Of the total 138 cases, the median age was 58 years (interquartile range (IQR) 44-69 years) and 70% were male. Eighty-one percent were immunocompromised (corticosteroid use (49%), hematological malignancy (20%), solid organ transplant (20%), solid organ malignancy (19%), and hematopoietic stem cell transplantation (15%)) and 29% had endovascular devices. Pulmonary infection was the most common concurrent site of clinical disease (67%). The median incubation time to the detection of Nocardia bacteremia was 4 days (IQR 3-6 days). Blood cultures were the only positive microbiological specimen in 38% of cases. The median total duration of treatment was 75 days (IQR 25-182 days). Thirty-day all-cause mortality was 28% and overall all-cause mortality was 40%. CONCLUSIONS: Nocardia bacteremia is most frequently identified in immunocompromised patients and those with intravascular devices. Although rare, it represents a serious infection with high associated overall mortality.
Asunto(s)
Bacteriemia/microbiología , Nocardiosis , Adulto , Anciano , Bacteriemia/complicaciones , Bacteriemia/tratamiento farmacológico , Bacteriemia/fisiopatología , Infecciones Relacionadas con Catéteres/tratamiento farmacológico , Infecciones Relacionadas con Catéteres/microbiología , Infecciones Relacionadas con Catéteres/patología , Infecciones Relacionadas con Catéteres/fisiopatología , Femenino , Humanos , Huésped Inmunocomprometido , Masculino , Persona de Mediana Edad , Nocardia/fisiología , Nocardiosis/complicaciones , Nocardiosis/tratamiento farmacológico , Nocardiosis/microbiología , Nocardiosis/fisiopatología , Estudios RetrospectivosRESUMEN
Seasonal influenza like illness results in increased hospital presentations and unnecessary antibiotic use. Recent availability of rapid respiratory virus PCR testing allows rapid, accurate influenza diagnosis. A retrospective audit of turnaround time from sample collection to result availability after introduction of Xpert® Flu/RSV in a tertiary healthcare institution during a high incidence influenza season is described.
Asunto(s)
Gripe Humana/diagnóstico , Técnicas de Diagnóstico Molecular/normas , Orthomyxoviridae/fisiología , Virus Sincitiales Respiratorios/fisiología , Infecciones del Sistema Respiratorio/diagnóstico , Infecciones del Sistema Respiratorio/virología , Estudios de Cohortes , Pruebas Diagnósticas de Rutina , Humanos , Gripe Humana/epidemiología , Gripe Humana/virología , Auditoría Médica , Orthomyxoviridae/genética , Virus Sincitiales Respiratorios/genética , Infecciones del Sistema Respiratorio/epidemiología , Estudios Retrospectivos , Estaciones del Año , Centros de Atención Terciaria , Factores de TiempoRESUMEN
The first case of Shigella-associated acalculous cholecystitis is described. A 27-year-old woman presented to hospital with diarrhoea and acute acalculous cholecystitis one day after return to Australia from Vietnam. Her feces culture grew multi-drug resistant ESBL-producing Shigella sonnei and she improved with antimicrobial therapy and intravenous fluids.
Asunto(s)
Colecistitis Alitiásica/microbiología , Farmacorresistencia Bacteriana Múltiple , Gastroenteritis/microbiología , Tracto Gastrointestinal/microbiología , Colecistitis Alitiásica/tratamiento farmacológico , Adulto , Antibacterianos/uso terapéutico , Australia , Escherichia coli/efectos de los fármacos , Escherichia coli/aislamiento & purificación , Femenino , Gastroenteritis/tratamiento farmacológico , Humanos , Shigella sonnei/efectos de los fármacos , Shigella sonnei/aislamiento & purificación , Viaje , VietnamRESUMEN
Acinetobacter baumannii is a common causative agent of hospital-acquired infections and a leading cause of infection in burns patients. Carbapenem-resistant A. baumannii is considered a major public-health threat and has been identified by the World Health Organization as the top priority organism requiring new antimicrobials. The most common mechanism for carbapenem resistance in A. baumannii is via horizontal acquisition of carbapenemase genes. In this study, we sampled 20 A. baumannii isolates from a patient with extensive burns, and characterized the evolution of carbapenem resistance over a 45 day period via Illumina and Oxford Nanopore sequencing. All isolates were multidrug resistant, carrying two genomic islands that harboured several antibiotic-resistance genes. Most isolates were genetically identical and represented a single founder genotype. We identified three novel non-synonymous substitutions associated with meropenem resistance: F136L and G288S in AdeB (part of the AdeABC efflux pump) associated with an increase in meropenem MIC to ≥8 µg ml-1; and A515V in FtsI (PBP3, a penicillin-binding protein) associated with a further increase in MIC to 32 µg ml-1. Structural modelling of AdeB and FtsI showed that these mutations affected their drug-binding sites and revealed mechanisms for meropenem resistance. Notably, one of the adeB mutations arose prior to meropenem therapy but following ciprofloxacin therapy, suggesting exposure to one drug whose resistance is mediated by the efflux pump can induce collateral resistance to other drugs to which the bacterium has not yet been exposed.
Asunto(s)
Acinetobacter baumannii/efectos de los fármacos , Carbapenémicos/farmacología , Acinetobacter baumannii/genética , Acinetobacter baumannii/aislamiento & purificación , Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismo , Ciprofloxacina/farmacología , Infección Hospitalaria/tratamiento farmacológico , ADN Bacteriano/genética , ADN Bacteriano/aislamiento & purificación , Farmacorresistencia Bacteriana Múltiple/genética , Humanos , Proteínas de Transporte de Membrana/genética , Proteínas de Transporte de Membrana/metabolismo , Meropenem/farmacología , Pruebas de Sensibilidad Microbiana , Tipificación de Secuencias Multilocus , Polimorfismo de Nucleótido Simple , Conformación Proteica , Análisis de Secuencia de ADN , beta-Lactamasas/genética , beta-Lactamasas/metabolismoRESUMEN
This data quality study assessed the accuracy of data collected as part of a pilot smaller-hospital surveillance program for methicillin-resistant Staphylococcus aureus (MRSA) infection and bloodstream infection (BSI). For reported MRSA infection, estimated values were as follows: sensitivity, 40%; specificity, 99.9%; and positive predictive value, 33.3%. For reported BSI, estimated values were as follows: sensitivity, 42.9%; specificity, 99.8%; and positive predictive value, 37.5%.
Asunto(s)
Bacteriemia/epidemiología , Resistencia a la Meticilina , Vigilancia de la Población/métodos , Infecciones Estafilocócicas/epidemiología , Bacteriemia/microbiología , Hospitales con menos de 100 Camas/estadística & datos numéricos , Hospitales Públicos/estadística & datos numéricos , Humanos , Proyectos Piloto , Valor Predictivo de las Pruebas , Control de Calidad , Sensibilidad y Especificidad , Staphylococcus aureus/efectos de los fármacos , Victoria/epidemiologíaRESUMEN
BACKGROUND: An infection control (IC) surveillance program for smaller (<100 acute beds) hospitals was piloted for 18 weeks in 14 hospitals. The aim of the pilot stage was to test a theoretical program in the context in which it was to be implemented. METHOD: An evaluation framework was developed, outlining the program's intended activities for data collection, management, analysis, reporting, and use. This framework was used as a reference to interview each of the 12 IC nurses participating in the pilot stage. RESULTS: The preferred case finding methodologies were not uniformly applied. Management, analysis, and reporting of data were delayed because of infrequent and irregular IC hours and laboratory reporting. Reports were not always distributed to key persons. Specific action was only taken in response to the process (and not outcome) module reports. CONCLUSION: Discrepancies between the theoretical and actual implementation of a surveillance program for smaller hospitals were highlighted. The program will need to be revised before it is rolled out to all 89 eligible hospitals across Victoria.