Lyme Disease, Anaplasmosis, and Babesiosis, Atlantic Canada.

In July 2021, a PCR-confirmed case of locally acquired Babesia microti infection was reported in Atlantic Canada. Clinical features were consistent with babesiosis and resolved after treatment. In a region where Lyme disease and anaplasmosis are endemic, the occurrence of babesiosis emphasizes the need to enhance surveillance of tickborne infections.

Phenotypic H-Antigen Typing by Mass Spectrometry Combined with Genetic Typing of H Antigens, O Antigens, and Toxins by Whole-Genome Sequencing Enhances Identification of Escherichia coli Isolates.

Mass spectrometry-based phenotypic H-antigen typing (MS-H) combined with whole-genome-sequencing-based genetic identification of H antigens, O antigens, and toxins (WGS-HOT) was used to type 60 clinical Escherichia coli isolates, 43 of which were previously identified as nonmotile, H type undetermined, or O rough by serotyping or having shown discordant MS-H and serotyping results. Whole-genome sequencing confirmed that MS-H was able to provide more accurate data regarding H antigen expression than serotyping. Further, enhanced and more confident O antigen identification resulted from gene cluster based typing in combination with conventional typing based on the gene pair comprising wzx and wzy and that comprising wzm and wzt The O antigen was identified in 94.6% of the isolates when the two genetic O typing approaches (gene pair and gene cluster) were used in conjunction, in comparison to 78.6% when the gene pair database was used alone. In addition, 98.2% of the isolates showed the existence of genes for various toxins and/or virulence factors, among which verotoxins (Shiga toxin 1 and/or Shiga toxin 2) were 100% concordant with conventional PCR based testing results. With more applications of mass spectrometry and whole-genome sequencing in clinical microbiology laboratories, this combined phenotypic and genetic typing platform (MS-H plus WGS-HOT) should be ideal for pathogenic E. coli typing.

Rapid, Sensitive, and Specific Escherichia coli H Antigen Typing by Matrix-Assisted Laser Desorption Ionization-Time of Flight-Based Peptide Mass Fingerprinting.

Matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) has gained popularity in recent years for rapid bacterial identification, mostly at the genus or species level. In this study, a rapid method to identify the Escherichia coli flagellar antigen (H antigen) at the subspecies level was developed using a MALDI-TOF MS platform with high specificity and sensitivity. Flagella were trapped on a filter membrane, and on-filter trypsin digestion was performed. The tryptic digests of each flagellin then were collected and analyzed by MALDI-TOF MS through peptide mass fingerprinting. Sixty-one reference strains containing all 53 H types and 85 clinical strains were tested and compared to serotyping designations. Whole-genome sequencing was used to resolve conflicting results between the two methods. It was found that DHB (2,5-dihydroxybenzoic acid) worked better than CHCA (α-cyano-4-hydroxycinnamic acid) as the matrix for MALDI-TOF MS, with higher confidence during protein identification. After method optimization, reference strains representing all 53 E. coli H types were identified correctly by MALDI-TOF MS. A custom E. coli flagellar/H antigen database was crucial for clearly identifying the E. coli H antigens. Of 85 clinical isolates tested by MALDI-TOF MS-H, 75 identified MS-H types (88.2%) matched results obtained from traditional serotyping. Among 10 isolates where the results of MALDI-TOF MS-H and serotyping did not agree, 60% of H types characterized by whole-genome sequencing agreed with those identified by MALDI-TOF MS-H, compared to only 20% by serotyping. This MALDI-TOF MS-H platform can be used for rapid and cost-effective E. coli H antigen identification, especially during E. coli outbreaks.

Cutaneous manifestations of a zoonotic Onchocerca species in an adult male, acquired in Nova Scotia, Canada.

A 65-year-old male with known hypertension and hypercholesterolemia sought medical attention because of a 3-month history of skin swelling on his upper back. Histopathology and molecular techniques were employed and identified an organism in the Onchocerca genus. This represents a very uncommon example of cutaneous infection by a zoonotic Onchocerca species.

Does sporadic Listeria gastroenteritis exist? A 2-year population-based survey in Nova Scotia, Canada.

BACKGROUND: Febrile gastroenteritis due to Listeria monocytogenes (LM) has been primarily described in foodborne outbreaks. We decided to determine the incidence of sporadic, febrile gastroenteritis due to LM in a large, well-defined North American population over a 2-year period and to compare these cases to sporadic cases of Campylobacter and Salmonella infections occurring concurrently in the community. METHODS: From 1 September 2002 through 31 August 2004, all stool specimens submitted for evaluation of diarrheal illness to a public health laboratory and to a children's hospital serving a population of approximately 350,000 were examined for the presence of Listeria species. Patients identified as having LM in their stool samples were matched with 2 temporally-matched patients with cultures positive for Campylobacter and Salmonella species. Patients with LM and control patients were contacted by telephone, and they answered a questionnaire that examined clinical features and risk factors for diarrheal illness. RESULTS: A total of 7775 stool specimens were submitted during the period 1 September 2002-31 August 2004. Thirty-nine Listeria species were recovered. Seventeen of the species were LM, 13 were Listeria innocua, 3 were Listeria welshimeri, 1 was Listeria grayi, and 4 were other species. Pulsed-field gel electrophoresis results demonstrated no temporal or other clusters, and no seasonality was noted for isolates of LM. Preexisting gastrointestinal problems were much more common in patients with LM (P=.001) than in patients with Campylobacter or Salmonella infections. CONCLUSIONS: Sporadic gastroenteritis due to LM appears to be an uncommon illness, and routine screening of stool samples for LM remains unwarranted. Preexisting gastrointestinal disease may be a risk factor for infection of the gastrointestinal tract with LM.