Campylobacter jejuni is a leading cause of enteric bacterial illness in the United States. Traditional molecular subtyping methods, such as pulsed-field gel electrophoresis (PFGE) and 7-gene multilocus sequencing typing (MLST), provided limited resolution to adequately identify C. jejuni outbreaks and separate out sporadic isolates during outbreak investigations. Whole genome sequencing (WGS) has emerged as a powerful tool for C. jejuni outbreak detection. In this investigation, 45 human and 11 puppy isolates obtained during a 2016-2018 outbreak linked to pet store puppies were sequenced. Core genome multilocus sequence typing (cgMLST) and high-quality single nucleotide polymorphism (hqSNP) analysis of the sequence data separated the isolates into the same two clades containing minor within clade differences; however, cgMLST analysis does not require selection of an appropriate reference genome making this method preferable to hqSNP analysis for Campylobacter surveillance and cluster detection. The isolates were classified as ST2109-a rarely seen MLST sequence type. PFGE was performed on 38 human and 10 puppy isolates; PFGE patterns did not reliably predict clustering by cgMLST analysis. Genetic detection of antimicrobial resistance determinants predicted that all outbreak-associated isolates would be resistant to six drug classes. Traditional antimicrobial susceptibility testing (AST) confirmed a high correlation between genotypic and phenotypic antimicrobial resistance determinations. WGS analysis linked C. jejuni isolates in humans and pet store puppies even when canine exposure information was unknown, aiding the epidemiological investigation during this outbreak. WGS data were also used to quickly identify the highly drug-resistant profile of these outbreak-associated C. jejuni isolates.

The Foodborne Diseases Active Surveillance Network (FoodNet) conducts population-based surveillance for Campylobacter infection. For 2010 through 2015, we compared patients with Campylobacter jejuni with patients with infections caused by other Campylobacter species. Campylobacter coli patients were more often >40 years of age (OR = 1.4), Asian (OR = 2.3), or Black (OR = 1.7), and more likely to live in an urban area (OR = 1.2), report international travel (OR = 1.5), and have infection in autumn or winter (OR = 1.2). Campylobacter upsaliensis patients were more likely female (OR = 1.6), Hispanic (OR = 1.6), have a blood isolate (OR = 2.8), and have an infection in autumn or winter (OR = 1.7). Campylobacter lari patients were more likely to be >40 years of age (OR = 2.9) and have an infection in autumn or winter (OR = 1.7). Campylobacter fetus patients were more likely male (OR = 3.1), hospitalized (OR = 3.5), and have a blood isolate (OR = 44.1). International travel was associated with antimicrobial-resistant C. jejuni (OR = 12.5) and C. coli (OR = 12) infections. Species-level data are useful in understanding epidemiology, sources, and resistance of infections.

A polyphasic study was undertaken to determine the taxonomic position of 13 Campylobacter fetus-like strains from humans (n=8) and reptiles (n=5). The results of matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF) mass spectrometry (MS) and genomic data from sap analysis, 16S rRNA and hsp60 sequence comparison, pulsed- field gel electrophoresis (PFGE), amplified fragment length polymorphism (AFLP) analysis, DNA-DNA hybridization and whole genome sequencing demonstrate that these strains are closely related to C. fetus but clearly differentiated from the present C. fetus subspecies. Therefore this unique cluster of 13 strains represents a novel subspecies within the species C. fetus, for which the name Campylobacter fetus subsp. testudinum subsp. nov. is proposed, with strain 03-427T (=ATCC BAA-2539T = LMG 27499T) as the type strain. Although this novel taxon cannot be differentiated from C. fetus subsp. fetus and C. fetus subsp. venerealis using conventional phenotypic tests, MALDI-TOF MS analysis revealed the presence of multiple phenotypic biomarkers which distinguish C. fetus subsp. testudinum from the present C. fetus subspecies.

From August to September 2008, the Centers for Disease Control and Prevention (CDC) assisted the Alaska Division of Public Health with an outbreak investigation of campylobacteriosis occurring among the residents of Southcentral Alaska. During the investigation, pulsed-field gel electrophoresis (PFGE) of Campylobacter jejuni isolates from human, raw pea and wild bird fecal samples confirmed the epidemiologic link between illness and the consumption of raw peas contaminated by Sandhill cranes from 15 of 43 epidemiologically-linked human isolates. However, an association between the remaining epidemiologically-linked human infections and the pea and wild bird isolates was not established. To better understand the molecular epidemiology of the outbreak, C. jejuni isolates (n=130; 59 humans, 40 peas and 31 wild birds) were further characterized by multi-locus sequence typing (MLST). Here, we present the molecular evidence to demonstrate the association of many more human C. jejuni infections associated with the outbreak with raw peas and wild bird feces. Among all sequence types (STs) identified, 26 (67%) of 39 were novel and exclusive to the outbreak. Five clusters of overlapping STs (n=32 isolates; 17 humans, 2 peas and 13 wild birds) were identified. In particular, Cluster E (n=7 isolates, ST-5049) consisted of isolates from humans, peas and wild birds. Novel STs clustered closely with isolates typically associated with wild birds and the environment, but distinct from lineages commonly seen in human infections. Novel STs and alleles recovered from human outbreak isolates allowed additional infections caused by these rare genotypes to be attributed to the contaminated raw peas.

To assess the spectrum of illness from toxigenic Vibrio cholerae O1 and risk factors for severe cholera in Haiti, we conducted a cross-sectional survey in a rural commune with more than 21,000 residents. During March 22-April 6, 2011, we interviewed 2,622 residents ≥ 2 years of age and tested serum specimens from 2,527 (96%) participants for vibriocidal and antibodies against cholera toxin; 18% of participants reported a cholera diagnosis, 39% had vibriocidal titers ≥ 320, and 64% had vibriocidal titers ≥ 80, suggesting widespread infection. Among seropositive participants (vibriocidal titers ≥ 320), 74.5% reported no diarrhea and 9.0% had severe cholera (reported receiving intravenous fluids and overnight hospitalization). This high burden of severe cholera is likely explained by the lack of pre-existing immunity in this population, although the virulence of the atypical El Tor strain causing the epidemic and other factors might also play a role.

BACKGROUND: Fifty-four outbreaks of domestically-acquired typhoid fever were reported between 1960-99. In 2010, the Southern Nevada Health District detected an outbreak of typhoid fever among persons who had not recently travelled abroad. METHODS: We conducted a case-control study to examine the relationship between illness and exposures. A case was defined as illness with the outbreak strain of Salmonella serotype Typhi, as determined by pulsed-field gel electrophoresis (PFGE), with onset during 2010. Controls were matched by neighborhood, age, and sex. Bivariate and multivariate statistical analysis was completed using logistic regression. Traceback investigation was completed. RESULTS: We identified twelve cases in three states with onset from April 15-September 4, 2010. The median age of case-patients was 18 years (range 4-48), eight (67%) were female, and 11 (92%) were Hispanic. Nine (82%) were hospitalized; none died. Consumption of frozen mamey pulp in a fruit shake was reported by 75% (6/8) of case-patients and no (0/33) controls (matched odds ratio [mOR]=33.9, 95% confidence interval [CI]= 4.9-undefined). Traceback investigations implicated two brands of frozen mamey pulp from a single manufacturer in Guatemala, which was also implicated in a 1998-99 outbreak of typhoid fever in Florida. CONCLUSION: Reporting of individual cases of typhoid fever and subtyping of isolates by pulsed-field gel electrophoresis resulted in rapid detection of an outbreak, associated with a ready-to- eat frozen food imported from a typhoid-endemic region. Improvements in food manufacturing practices and monitoring will prevent additional outbreaks from occurring.

Previous studies have shown a positive association between chronic typhoid carriage and biliary cancers. We compared serum Salmonella enterica serovar Typhi antibody titers between biliary tract cancer cases, biliary stone cases without evidence of cancer, and healthy subjects in a large population-based case-control study in Shanghai, China. Participants included 627 newly diagnosed primary biliary tract cancer patients; 1,037 biliary stone cases (774 gallbladder and 263 bile-duct) and 959 healthy subjects without a history of cancer, randomly selected from the Shanghai Resident Registry. Overall only 6/2,293 (0.26%) were Typhi positive. The prevalence of Typhi was 1/457 (0.22%), 4/977 (0.41%), and 1/859 (0.12%) among cancer cases, biliary-stone cases, and population controls, respectively. We did not find an association between Typhi and biliary cancer in Shanghai, due to the very low prevalence of chronic carriers in this population.The low seroprevalence of S. Typhi in Shanghai is unlikely to explain the high incidence of biliary cancers in this population.

BACKGROUND: Campylobacter jejuni is a leading cause of acute gastroenteritis worldwide, and most cases are identified as sporadic events rather than as parts of recognized outbreaks. We report findings from a substantial 2008 campylobacteriosis outbreak with general implications for fresh produce safety. METHODS: We conducted a matched case-control study to determine the source of the outbreak and enhanced surveillance to identify additional cases. Clinical and environmental specimens were tested for Campylobacter, and isolates were subtyped by pulsed-field gel electrophoresis (PFGE). RESULTS: By routine surveillance, we identified 63 cases of laboratory-confirmed infection. Only raw peas, consumed by 30 (67%) of 45 case-patients and by 15 (17%) of 90 control participants, were associated with illness (adjusted odds ratio: 8.2; P < .001). An additional 69 patients (26 laboratory-confirmed) who reported eating raw peas within 10 days of illness onset were identified through enhanced surveillance. In all, 5 cases were hospitalized, and Guillain-Barre syndrome developed in 1 case; none died. The implicated pea farm was located near a Sandhill crane (Grus canadensis) stopover and breeding site. Of 36 environmental samples collected, 16 were positive for C. jejuni-14 crane-feces samples and 2 pea samples. We identified 25 unique combined SmaI-KpnI PFGE patterns among clinical isolates; 4 of these combined PFGE patterns identified in 15 of 55 human isolates were indistinguishable from PFGE patterns identified in environmental samples. CONCLUSIONS: This investigation established a rare laboratory-confirmed link between a campylobacterosis outbreak and an environmental source and identified wild birds as an underrecognized source of produce contamination.

Reptile Campylobacter fetus isolates and closely related strains causing human disease were characterized by multilocus sequence typing. They shared approximately 90% nucleotide sequence identity with classical mammalian C. fetus and there was evidence of recombination amongst these two groups. The reptile group represents a possible separate genomospecies capable of infecting humans.