A large food-borne outbreak of campylobacteriosis in kindergartens and primary schools in Pescara, Italy, May-June 2018

Global epidemiology of campylobacteriosis and the impact of COVID-19

Campylobacteriosis is a gastroenteritis caused by pathogenic Campylobacter species and an important topic in public health. Here we review the global epidemiology of campylobacteriosis in the last eight years between 2014-2021, providing comprehensive and updated information on the reported incidence and outbreaks of Campylobacter infections. The government public health website of each of the 195 countries and publications from 2014 to September 2022 in public databases were searched. The reported incidence of campylobacteriosis in pre-COVID-19 years was compared to that during the COVID-19 pandemic in countries where data were available. Czech Republic had the highest reported incidence of campylobacteriosis worldwide (215 per 100,000 in 2019), followed by Australia (146.8 per 100,000 in 2016) and New Zealand (126.1 per 100,000 in 2019). Campylobacter was one of the most common human enteric pathogens in both developed and developing countries. About 90% of cases of campylobacteriosis were caused by Campylobacter jejuni, whereas less than 10% of cases were caused by Campylobacter coli. Other Campylobacter species were also isolated. The reported incidence and case numbers of campylobacteriosis in developed nations have remained steadily high prior to the COVID-19 pandemic, whilst some countries reported an increasing trend such as France and Japan. While outbreaks were more frequently reported in some countries, Campylobacter infections were mainly sporadic cases in most of the developed countries. Campylobacter infection was more common in summer in some but not all countries. Campylobacter infection was more common in males than females. The COVID-19 pandemic has reduced the reported incidence of campylobacteriosis in most countries where 2020 epidemiology data were available. In conclusion, Campylobacter infection remains a global health concern. Increased research and improved strategies are needed for prevention and reduction of Campylobacter infection.

Genomic Analysis Reveals That Isolation Temperature on Selective Media Introduces Genetic Variation in Campylobacter jejuni from Bovine Feces

Campylobacter jejuni is commonly isolated on selective media following incubation at 37 °C or 42 °C, but the impact of these temperatures on genome variation remains unclear. Previously, Campylobacter selective enrichments from the feces of steers before and after ceftiofur treatment were plated on selective agar media and incubated at either 37 °C or 42 °C. Here, we analyzed the whole genome sequence of C. jejuni strains of the same multilocus sequence typing (MLST)-based sequence type (ST) and isolated from the same sample upon incubation at both temperatures. Four such strain pairs (one ST8221 and three ST8567) were analyzed using core genome and whole genome MLST (cgMLST, wgMLST). Among the 1970 wgMLST loci, 7-25 varied within each pair. In all but one of the pairs more (1.7-8.5 fold) new alleles were found at 42 °C. Most frameshift, nonsense, or start-loss mutations were also found at 42 °C. Variable loci CAMP0575, CAMP0912, and CAMP0913 in both STs may regularly respond to different temperatures. Furthermore, frameshifts in four variable loci in ST8567 occurred at multiple time points, suggesting a persistent impact of temperature. These findings suggest that the temperature of isolation may impact the sequence of several loci in C. jejuni from cattle.