bacteraemia secondary to an empyema in an immunocompromised host: A case report and review of the literature.

Introduction: infection remains uncommon. More cases of bacteraemia are reported in recent years with the primary infection largely originating from skin and soft tissue sites. Yet, our understanding of its virulence, antibiotic susceptibility profile and treatment is still limited.

A Study of Analytical and Clinical Sensitivity of Aptima SARS-CoV-2 Assay (Hologic) and Proposals of Complementary Tests for SARS-CoV-2 Detection in Low Viral Load Specimens.

Early and accurate detection of SARS-CoV-2 is important for diagnosis and transmission control. The use of high-throughput and automated testing allows laboratories to better deliver diagnostic testing given manpower and resource limitations. We validated the clinical and analytical performance of the Hologic Panther Aptima SARS-CoV-2 assay with an emphasis on detection of specimens with low viral loads.

Development of a rapid multiplex PCR assay for the detection of common pathogens associated with community-acquired pneumonia.

Background: Community-acquired pneumonia (CAP) is one of the most common infectious diseases and is a significant cause of mortality and morbidity globally. A microbial cause was not determined in a sizable percentage of patients with CAP; there are increasing data to suggest regional differences in bacterial aetiology. We devised a multiplex real-time PCR assay for detecting four microorganisms (Streptococcus pneumoniae, Haemophilus influenzae, Klebsiella pneumoniae and Burkholderia pseudomallei) of relevance to CAP infections in Asia.

Prevalence and antibiotic susceptibility of colistin-resistance gene (mcr-1) positive Enterobacteriaceae in stool specimens of patients attending a tertiary care hospital in Singapore.

Objectives: The aim of this study was to determine the prevalence of the colistin-resistance gene (mcr-1) and the antibiotic-susceptibility profile of mcr-1 positive, colistin-resistant isolates in stool specimens of patients attending a tertiary care hospital in Singapore.

Methods: 201 diarrheal stool specimens of patients attending the Changi General Hospital between May to August 2017 were collected and screened for the presence of mcr-1 by culture and molecular methods. Antibiotic-susceptibility profile of mcr-1 positive isolates was determined using the polymyxin B and colistin E-tests and the VITEK 2 system.

Retrospective genome-wide comparisons of Salmonella enterica serovar Enteritidis from suspected outbreaks in Singapore.

The number of salmonellosis cases in Singapore has increased over the years. Salmonella enterica serovar Enteritidis has always been the most predominant serovar in the last five years. The National Public Health Laboratory assisted outbreak investigations by performing multilocus variable number tandem repeat analysis (MLVA) on isolates that were collected at the time of the investigations.

Draft Genome Sequence of Singapore subsp. Isolate DS32358_14, Which Contains the Carbapenemase Gene .

We sequenced the first -positive strain isolated in Singapore. The isolate belongs to multilocus sequence type 2542 (ST2542), and was the first gene in an integron that also contained , , , , , and .

Putative Integrative Mobile Elements That Exploit the Xer Recombination Machinery Carrying -Type Carbapenemase Genes in Enterobacter cloacae Complex Isolates in Singapore.

Whole-genome sequencing was performed on 16 isolates of the carbapenemase-producing complex to determine the flanking regions of -type genes. Phylogenetic analysis of multilocus sequence typing (MLST) targets separated the isolates into 4 clusters. The -type genes were all found on Xer-dependent integrative mobile elements (IMEX).

Colistin and Polymyxin B Susceptibility Testing for Carbapenem-Resistant and -Positive Enterobacteriaceae: Comparison of Sensititre, MicroScan, Vitek 2, and Etest with Broth Microdilution.

Colistin and polymyxin B remain part of the last line of antibiotics for multidrug-resistant Gram-negative bacteria, such as carbapenem-resistant Current joint EUCAST-CLSI recommendations are for broth microdilution (BMD) to be performed for MIC testing of colistin. Commercial susceptibility testing methods were evaluated and compared against the reference BMD, using a susceptibility breakpoint of ≤2 mg/liter for both colistin and polymyxin B. Seventy-six were included, of which 21 were positive (18 isolates, 2 isolates, and 1 isolate).

Clinical and Molecular Epidemiology of Carbapenem-Resistant Enterobacteriaceae Among Adult Inpatients in Singapore.

Background: Since 2010, the incidence of carbapenem-resistant Enterobacteriaceae (CRE) has been increasing in Singapore. We analyzed the clinical and molecular epidemiology of CRE among adult inpatients in Singapore.

Methods: Quarterly incidence of unique subjects (per 100000 patient-days) with positive clinical and surveillance cultures for CRE were estimated based on mandatory data submitted to the National Public Health Laboratory by public hospitals between 2010 and 2015.

Development and evaluation of a multiplex real-time PCR for the detection of IMP, VIM, and OXA-23 carbapenemase gene families on the BD MAX open system.

A multiplex real-time polymerase chain reaction (PCR) assay was developed for the detection of clinically prevalent IMP, VIM, and OXA-23 gene families. The assay was designed to work on the BD MAX open platform which is a fully automated system for all PCR processes including sample extraction to PCR resulting. A total of 107 well-characterized carbapenem resistant Enterobacteriaceae were evaluated and the results were 100% concordant with the reference test isolates.

Tracking inter-institutional spread of NDM and identification of a novel NDM-positive plasmid, pSg1-NDM, using next-generation sequencing approaches.

Objectives: Owing to gene transposition and plasmid conjugation, New Delhi metallo-β-lactamase (NDM) is typically identified among varied Enterobacteriaceae species and STs. We used WGS to characterize the chromosomal and plasmid molecular epidemiology of NDM transmission involving four institutions in Singapore.

Methods: Thirty-three Enterobacteriaceae isolates (collection years 2010-14) were sequenced using short-read sequencing-by-synthesis and analysed.

Outbreak of New Delhi metallo-β-lactamase-1-producing Enterobacter cloacae in an acute care hospital general ward in Singapore.

Background: Autochthonous infections with New Delhi metallo-β-lactamase-1 (NDM-1)-producing Enterobacteriaceae have been reported in Singapore since 2011, but occurrences of nosocomial transmission have not. We report an outbreak of NDM-1-producing Enterobacter cloacae among adults admitted to an acute hospital's general ward.

Methods: On detecting the index case with a culture specimen positive for NDM-1-producing E cloacae, active case finding was conducted by screening all possible patient contacts.

Performance assessment of the BD MAX Cdiff assay in comparison to Xpert C. difficile assay in a setting with very low prevalence of toxigenic Clostridium difficile PCR ribotype 027.

In a clinical setting with low prevalence of 'epidemic' PCR ribotype 027, the BD MAX Cdiff assay was found to be a suitable alternative to the Xpert C. difficile assay for the detection of toxigenic Clostridium difficile in samples which are reflex PCR tested after obtaining a discrepant immunoassay result. There was no significant difference between the sensitivities and specificities of both commercial molecular assays.

Surveillance trends of carbapenem-resistant Enterobacteriaceae from Singapore, 2010-2013.

Trends in carbapenem-resistant Enterobacteriaceae (CRE) collected from hospitals nationwide in Singapore over 3 years are presented. Hospital isolates with imipenem or meropenem minimum inhibitory concentrations (MICs) of >1mg/L were sent to the National Public Health Laboratory for further investigation. A total of 400 CRE were submitted, 227 (56.

Enterobacter cloacae producing an uncommon class A carbapenemase, IMI-1, from Singapore.

In this study, we describe the characterization of an infrequently encountered class A carbapenemase, IMI-1, from a clinical Enterobacter cloacae isolate. The isolate had high levels of resistance to carbapenems but retained susceptibility to expanded-spectrum cephalosporins. The blaIMI-1 gene was chromosomally encoded.

Finegoldia magna, an early post-operative cause of infectious endocarditis: report of two cases and review of the literature.

We report two cases of infectious endocarditis (IE) on prosthetic valves caused by Finegoldia magna. The diagnosis was obtained by detection of the bacterium in valvular biopsies using 16S rRNA PCR amplication and sequencing, and prolonged culture. Five other cases were previously published in the literature.

Regulation of whole bacterial pathogen transcription within infected hosts.

DNA microarrays are a powerful and promising approach to gain a detailed understanding of the bacterial response and the molecular cross-talk that can occur as a consequence of host-pathogen interactions. However, published studies mainly describe the host response to infection. Analysis of bacterial gene regulation in the course of infection has confronted many challenges.

Development of a method for recovering rickettsial RNA from infected cells to analyze gene expression profiling of obligate intracellular bacteria.

The Rickettsia genus is composed of Gram-negative bacteria responsible for Typhus and spotted fevers. Because of the limitations imposed by their obligate intracellular location, the molecular mechanisms responsible for their pathogenicity remain poorly understood. Several rickettsial genomes are now available, thus providing the foundation for a new era of post-genomic research.

Comparative genomic analysis of Tropheryma whipplei strains reveals that diversity among clinical isolates is mainly related to the WiSP proteins.

Background: The aim of this study was to analyze the genomic diversity of several Tropheryma whipplei strains by microarray-based comparative genomic hybridization. Fifteen clinical isolates originating from biopsy samples recovered from different countries were compared with the T. whipplei Twist strain.

Molecular basis of Tropheryma whipplei doxycycline susceptibility examined by transcriptional profiling.

Objectives And Methods: Tropheryma whipplei is a poorly studied bacterium responsible for Whipple's disease. In this study, its susceptibility to doxycycline was investigated at a transcriptional level using a whole-genome DNA microarray.

Results: Exposure of T.