Whole-genome sequencing data of Corynebacterium diphtheriae isolated from diphtheria outbreaks in Indonesia.

Corynebacterium diphtheriae (C. diphtheriae) is the causative agent of diphtheria. The main virulence factor of C. diphtheriae is diphtheria toxin, which is encoded by the tox gene and regulated by the dtxR gene. The tox and dtxR genes are used as genetic markers to identify bacteria causing diphtheria by PCR. Here, we present the whole-genome sequencing (WGS) data of 18 C. diphtheriae isolates from diphtheria outbreaks in different regions in Indonesia. We used these data to identify single nucleotide polymorphisms (SNPs) associated with the tox and dtxR genes to verify the accuracy of the PCR assay and performed molecular typing with a multilocus sequence typing (MLST) approach. The data can be used for further analyses, such as antimicrobial resistance and bacterial virulence factors.

Laboratory and epidemiology data of pertussis cases and close contacts: A 5-year case-based surveillance of pertussis in Indonesia, 2016-2020.

Pertussis cases have been reported most frequently in developed countries, but they are predicted to be the most prevalent in developing countries. Indonesia, a developing country, routinely conducts case-based surveillance for pertussis. We reviewed the data on pertussis cases and close contacts based on clinical sample documents examined in the National Reference Laboratory for pertussis, Indonesia (2016-2020). Our objective was to analyze the laboratory and epidemiological aspects of pertussis cases and close contacts, particularly to evaluate the implementation of a 5-year case-based surveillance of pertussis in Indonesia. Data were collected from sample documents and annual laboratory reports between January 2016 and December 2020. We analyzed the proportion of pertussis cases and close contacts by geographic region, year, age, and sex. We used the χ2 test to correlate the laboratory and epidemiological data. In total, 274 clinical cases of pertussis and 491 close contacts were recorded in 15 provinces. The peak number of cases occurred in 2019, with a positivity rate (percentage of laboratory-confirmed cases) of 41.23% (47/114). Clinical cases were dominated by infants aged <1 year (55.5%), and 52.9% of them were aged <6 months. Similarly, 72.3% (68/94) of the laboratory-confirmed cases were infants. Both clinical cases and positivity rates tended to be higher in females (155 cases, 38.1%) than in males (119 cases, 29.4%). No confirmed cases were found in children aged ≥10 years, although positive results still occurred in close contact. Age-group and laboratory-confirmed cases were correlated (p = 0.00). Clinical and confirmed cases of pertussis occurred mostly in the early age group and may be lower in those aged ≥10 years, especially in confirmed cases. New policies are needed for pertussis prevention at an early age, as well as the application of serology tests to increase laboratory-confirmed cases in children aged ≥10 years.

Extended spectrum beta-lactamase-producing Escherichia coli surveillance in the human, food chain, and environment sectors: Tricycle project (pilot) in Indonesia.

The World Health Organization (WHO) has been implementing antimicrobial surveillance with a "One Health" approach, known as the Global Surveillance ESBL E. coli Tricycle Project. We describe the implementation of the Tricycle Project (pilot) in Indonesia, focusing on its results, challenges and recommendations. The samples were 116 patients with bloodstream infections caused by ESBL E. coli, 100 rectal swabs collected from pregnant women, 240 cecums of broiler, and 119 environmental samples, using the standardized method according to the guidelines. ESBL-producing E. coli was found in 40 (40%) of the 100 pregnant women, while the proportion of ESBL-producing E. coli was 57.7% among the total E. coli-induced bloodstream infections. ESBL-producing E. coli was isolated from 161 (67.1%) out of 240 broilers. On the other hand, the average concentration of E. coli in the water samples was 2.0 × 108 CFU/100 mL, and the ratio of ESBL-producing E. coli was 12.8% of total E. coli. Unfortunately, 56.7% of questionnaires for patients were incomplete. The Tricycle Project (pilot) identified that the proportion of ESBL-producing E. coli was very high in all types of samples, and several challenges and obstacles were encountered during the implementation of the study in Indonesia. The finding of this study have implication to health/the antimicrobial resistance (AMR) surveillance. We recommend continuing this project and extending this study to other provinces to determine the AMR burden as the baseline in planning AMR control strategies in Indonesia. We also recommend improving the protocol of this study to minimize obstacles in the field.

New approach for the identification of potentially toxigenic Corynebacterium sp. using a multiplex PCR assay.

In diphtheria laboratory examinations, the PCR test can be applied to isolates and clinical specimens. This study aimed to develop a PCR assay to identify the species and toxigenicity of diphtheria-causing bacteria, including the prediction of some NTTB types. Seven reference isolates, four synthetic DNA samples, 36 stored isolates, and 487 clinical samples used for PCR optimization. The PCR results was confirmed by DNA sequence analysis. The results of the PCR examination of the 7 reference isolates and 36 stored isolates were similar to the results obtained using conventional methods as gold standard, both for diphtheria-causing and non-diphtheria-causing bacteria. The validation of the PCR results using DNA sequence analysis showed that there was no mispriming or misamplification. The multiplex PCR assay developed in this study could correctly identify the species and toxigenicity of diphtheria-causing bacteria, including the prediction of some NTTB types not yet covered by established PCR methods.