Frequency and mortality rate following antimicrobial-resistant bloodstream infections in tertiary-care hospitals compared with secondary-care hospitals

There are few studies comparing proportion, frequency, mortality and mortality rate following antimicrobial-resistant (AMR) infections between tertiary-care hospitals (TCHs) and secondary-care hospitals (SCHs) in low and middle-income countries (LMICs) to inform intervention strategies. The aim of this study is to demonstrate the utility of an offline tool to generate AMR reports and data for a secondary data analysis. We conducted a secondary-data analysis on a retrospective, multicentre data of hospitalised patients in Thailand. Routinely collected microbiology and hospital admission data of 2012 to 2015, from 15 TCHs and 34 SCHs were analysed using the AMASS v2.0 (www.amass.website). We then compared the burden of AMR bloodstream infections (BSI) between those TCHs and SCHs. Of 19,665 patients with AMR BSI caused by pathogens under evaluation, 10,858 (55.2%) and 8,807 (44.8%) were classified as community-origin and hospital-origin BSI, respectively. The burden of AMR BSI was considerably different between TCHs and SCHs, particularly of hospital-origin AMR BSI. The frequencies of hospital-origin AMR BSI per 100,000 patient-days at risk in TCHs were about twice that in SCHs for most pathogens under evaluation (for carbapenem-resistant Acinetobacter baumannii [CRAB]: 18.6 vs. 7.0, incidence rate ratio 2.77; 95%CI 1.72–4.43, p0.20). Due to the higher frequencies, all-cause in-hospital mortality rates following hospital-origin AMR BSI per 100,000 patient-days at risk were considerably higher in TCHs for most pathogens (for CRAB: 10.2 vs. 3.6,mortality rate ratio 2.77; 95%CI 1.71 to 4.48, p<0.001; CRPA: 1.6 vs. 0.8; p = 0.020; 3GCREC: 4.0 vs. 2.4, p = 0.009; 3GCRKP, 4.0 vs. 1.8, p<0.001; CRKP: 0.8 vs. 0.3, p = 0.042; and MRSA: 2.3 vs. 1.1, p = 0.023). In conclusion, the burden of AMR infections in some LMICs might differ by hospital type and size. In those countries, activities and resources for antimicrobial stewardship and infection control programs might need to be tailored based on hospital setting. The frequency and in-hospital mortality rate of hospital-origin AMR BSI are important indicators and should be routinely measured to monitor the burden of AMR in every hospital with microbiology laboratories in LMICs

Vibrio cholerae embraces two major evolutionary traits as revealed by targeted gene sequencing

Vibrio cholerae inhabits aquatic environments worldwide and has over 200 recognized serogroups classified by O-polysaccharide specificity. Here, we report that V. cholerae selects either of two genetic traits during their evolution. Sequencing of the specific gene locus MS6_A0927 revealed that 339 of 341 strains of V. cholerae and closely related Vibrio species originating from 34 countries over a century carried either metY (M) (~1, 269 bp) or luxR-hchA (LH) (~1, 600 bp) genes, and consequently those vibrios were separated into two clusters, M (45.4%) and LH (54.6%). Only two strains contained both M and LH in the same locus. Moreover, extensive polymorphisms in those genes were detected in M and LH with 79 and 46 sequence variations, respectively. V. cholerae O1 strains isolated from cholera outbreaks worldwide, and some non-O1 strains evolving from O1 via exchange of genes encoding cell surface polysaccharides possessed LH alleles. Analysis of polymorphisms in the gene locus implicated a high degree of genetic diversity and identical subpopulations among the V. cholerae species

<i>Burkholderia pseudomallei</i> Biofilm Promotes Adhesion, Internalization and Stimulates Proinflammatory Cytokines in Human Epithelial A549 Cells - Fig 1

<p><b>(A)</b> Fluorescence microscopic views of the 2-day biofilms of <i>B</i>. <i>pseudomallei</i> H777, M10 and C17 grown statically on glass slides in LB broth at 37°C. The biofilms were stained with FITC-ConA and monitored under a Nikon Eclipse Ni-U fluorescence microscope (20× magnification). Strains H777 and C17 showed aggregation of surface-adherent bacteria whereas the biofilm mutant, M10, was rarely attached on the glass slide. (B) Confocal laser scanning micrographs of the 2-day biofilms of <i>B</i>. <i>pseudomallei</i> H777, M10 and C17 grown statically on glass slides in LB broth at 37°C. The biofilms were stained with FITC-ConA. The crossing lines in each images (x and y axes) indicate the correspondent vertical CLSM section (Z), indicating the thickness of the biofilm. The bars indicate 5 μm. The images were taken using a Zeiss 500 and a Zeiss 800 CLSM microscope (100× magnification).</p

Intracellular survival and multiplication of <i>B</i>. <i>pseudomallei</i> H777, M10 and C17 strains in human lung epithelial cells at MOI 10.

<p>The number of bacteria present were enumerated at 4, 8 and 12 h p.i. using the drop plate technique. Data are represented as means ± standard deviation from at least three independent experiments in triplicate wells.</p

Adhesion of <i>B</i>. <i>pseudomallei</i> H777, M10 and C17 to human lung epithelial cells at MOI 10.

<p>(A) Percentages of bacterial adhesion were determined by comparing the number of adherent bacteria to the inoculum. The numbers of CFU of cell-associated bacteria were counted after 1 h p.i. using the drop plate technique. Data represent the mean ± standard deviation of triplicates from at least three independent experiments. Asterisks denote statistical significance relative to H777 (<i>p</i> < 0.05). (B) Light microscopic images demonstrating <i>B</i>. <i>pseudomallei</i> H777, M10 and C17 adhesion to A549 cells. Bar represents 10 μm. Representative images from Giemsa stained specimens and visualized under 100× magnification.</p

Cytokine production by human lung epithelial cells (A549) in response to infection with <i>B</i>. <i>pseudomallei</i> H777, M10 and C17 strains.

<p>A549 cells were infected at MOI 10 and MOI 100. The culture supernatants were harvested at 8 h p.i. to measure cytokine levels. Data represent the means ± standard errors for triplicate wells of single representative experiments. Each experiment was performed at least three times. Asterisks denote statistical significance (<i>p</i> < 0.05).</p

The 1^st EQAsia External Quality Assessment trial:<i>Escherichia coli</i> and <i>Salmonella </i>spp. – 2021

The EQAsia project was launched in 2020 aiming to strengthen the provision of External Quality Assessment (EQA) services across the One Health sector among National Reference Laboratories/ Centres of Excellence in South and Southeast Asia. EQAsia is supported by the Fleming Fund and strives to increase the quality of laboratory-based surveillance of WHO GLASS pathogens and FAO priority pathogens.The EQAsia Consortium includes the National Food Institute, Technical University of Denmark (DTU Food) as the Lead Grantee, the International Vaccine Institute (IVI) in South Korea, the National Institute of Health (NIH) in Thailand and the Faculty of Veterinary Science, Chulalongkorn University (CU) in Thailand.EQASIA provides a state of the art EQA program free of charge for the South and Southeast Asian region through existing local providers (NIH Thailand and CU Thailand). The program, referred to as a “One-Shop EQA program”, is designed to enable the laboratories to select and participate in relevant proficiency tests of both pathogen identification and antimicrobial susceptibility testing (AST), in line with the requirements of the WHO GLASS. The EQA program is supported by an informatics module where laboratories can report their results and methods applied.Three EQA trials are taking place during Feb 2021 – Feb 2022. The EQA trials focus on the WHO GLASS pathogens and FAO priority pathogens (see Section 7. References): Salmonella spp., Escherichia coli, Klebsiella pneumoniae, Shigella spp., Acinetobacter spp., Staphylococcus aureus, Streptococcus pneumoniae, Campylobacter (C. coli and C. jejuni), Enterococci (E. faecium and E. faecalis), Pseudomonas aeruginosa and Neisseria gonorrhoeae. In addition, a Matrix EQA is offered, aligning with the scope of WHO Tricycle and suggested from FAO, aiming to assess the veterinary laboratories’ ability to detect ampC beta-lactamases (ampC), extended-spectrum beta-lactamases (ESBL) and carbapenemase producing E. coli from animal caeca samples and food matrices.For a given organism, candidate strains are assessed and validated by DTU and the external partner (United States Food and Drug Administration, FDA). The validation includes both phenotypic minimum inhibitory concentration (MIC) determination by broth microdilution, and whole genome sequencing (WGS) to detect antimicrobial resistance (AMR) genes and chromosomal point mutations. The test strains are then selected based on the phenotypic AMR profile to include a heterogeneous panel, allowing for strain variation from almost pan-resistant to fully susceptible isolates.Each EQA trial encompasses the testing of a total of 11 test strains of a given organism. Of these, eight of the test strains are of the organism in focus (target organism), whereas three test strains are different from the targeted species (reported as non-[organism], e.g. non-Salmonella). For each of the 11 test strains, participants are requested to report which eight strains belong to the expected target organism. For the three organisms different from the expected, no further testing is required. For the remaining eight test strains of the target organism, results in relation to AST and serotyping (if relevant) are requested.This report contains results from the first EQA trial of the EQAsia project carried out in February-April 2021. This first EQA trial includes serotyping of Salmonella spp., as well as identification and AST of Salmonella spp. and Escherichia coli. The aim of this EQA trial is to monitor the quality of AST results produced by the participating laboratories and identify underperforming laboratories in need of assistance to improve their performance in AST.The evaluation of the participants’ results is based on international guidelines, namely the European Committee on Antimicrobial Susceptibility Testing (EUCAST) and the Clinical and Laboratory Standards Institute (CLSI). Interpretative criteria referring to both disk diffusion and MIC determination are listed in the EQA protocol (Appendix 1) and allow for the obtained results to be interpreted into categories as resistant or susceptible depending on the method used. Results in agreement with the expected interpretation are categorised as ‘1’ (correct), while results deviating from the expected interpretation are categorised as ‘0’ (incorrect). This standardized interpretation of results is necessary to allow comparison of performance between laboratories. Laboratory performance is considered acceptable if there are &lt; 5% deviation from expected results.Evaluation of a result as “deviating from the expected interpretation” should be carefully analysed in a route cause analysis procedure performed by individual participants (self-evaluation) when the EQA results are disclosed. The methods applied have limitations in reproducibility, thus, on repeated testing, the same strain/antimicrobial combination can result in different MIC or Inhibition Zone Diameter values differing by one-fold dilution or ±3mm, respectively. If the expected MIC/Zone Diameter is close to the threshold for categorising the strain as susceptible or resistant, a one-fold dilution/±3mm difference may result in different interpretations. Since this report evaluates the interpretations of MIC/Zone Diameter and not the values, some participants may find their results classified as incorrect even though the actual MIC/Zone Diameter measured is only one-fold dilution/±3mm different from the expected MIC/Zone Diameter. In these cases, the participants should be confident about the good quality of their AST performance.In this report, results from laboratories affiliated with the Human Health (HH) or the Animal Health (AH) Sectors are presented separately. The laboratories are identified by codes and each code is known only by the corresponding laboratory and the organizers. The full list of laboratory codes is confidential and known only by the EQAsia Consortium.This report is approved in its final version by a Technical Advisory Group composed by members of the EQAsia Consortium, and by the EQAsia Advisory Board members Navin Karan (Pacific Pathology Training Centre, New Zealand), Monica Lahra (WHO Collaborating Center for STI and AMR, NSW Health Pathology Microbiology, New South Wales, Australia) and Ben Howden (The Peter Doherty Institute for Infection and Immunity, Australia).<br/