Long-Term Sentinel Surveillance for Enterotoxigenic Escherichia coli and Non-O157 Shiga Toxin-Producing E. coli in Minnesota.

Background. Enterotoxigenic Escherichia coli (ETEC) and non-O157 Shiga toxin-producing E. coli (STEC) are not detected by conventional culture methods. The prevalence of ETEC infections in the United States is unknown, and recognized cases are primarily associated with foreign travel. Gaps remain in our understanding of STEC epidemiology. Methods. Two sentinel surveillance sites were enrolled: an urban health maintenance organization laboratory (Laboratory A) and a rural hospital laboratory (Laboratory B). Residual sorbitol MacConkey (SMAC) plates from stool cultures performed at Laboratory A (1996-2006) and Laboratory B (2000-2008) were collected. Colony sweeps from SMAC plates were tested for genes encoding STEC toxins stx1 and stx2 (1996-2008) and ETEC heat-labile and heat-stable toxins eltB, estA 1, 2 and 3 (2000-2008) by polymerase chain reaction (PCR)-based assays. Results. In Laboratory A, a bacterial pathogen was identified in 7.0% of 21 970 specimens. During 1996-2006, Campylobacter was the most common bacterial pathogen (2.7% of cultures), followed by Salmonella (1.2%), Shigella (1.0%), and STEC (0.9%). Among STEC (n = 196), O157 was the most common serogroup (31%). During 2000-2006, ETEC (1.9%) was the second most common bacterial pathogen after Campylobacter (2.6%). In Laboratory B, of 19 293 specimens tested, a bacterial pathogen was identified for 5.5%, including Campylobacter (2.1%), STEC (1.3%), Salmonella (1.0%), and ETEC (0.8%). Among STEC (n = 253), O157 was the leading serogroup (35%). Among ETEC cases, 61% traveled internationally. Conclusions. Enterotoxigenic E. coli and STEC infections were as common as most other enteric bacterial pathogens, and ETEC may be detected more frequently by culture-independent multiplex PCR diagnostic methods. A high proportion of ETEC cases were domestically acquired.

Non-O157 Shiga toxin-producing Escherichia coli associated with venison.

We investigated an outbreak of non-O157 Shiga toxin-producing Escherichia coli at a high school in Minnesota, USA, in November 2010. Consuming undercooked venison and not washing hands after handling raw venison were associated with illness. E. coli O103:H2 and non-Shiga toxin-producing E. coli O145:NM were isolated from ill students and venison.

Characteristics of O157 versus non-O157 Shiga toxin-producing Escherichia coli infections in Minnesota, 2000-2006.

BACKGROUND: Escherichia coli O157:H7 (O157) is the Shiga toxin-producing E. coli (STEC) serotype most frequently isolated and most often associated with hemolytic uremic syndrome (HUS) in the United States. Non-O157 STEC serotypes can also cause serious illness, but their impact as pathogens remains undefined. We compared characteristics of non-O157 and O157 STEC infections identified through sentinel surveillance. METHODS: Sentinel sites included a metropolitan health maintenance organization laboratory and a hospital laboratory serving a small city and rural area. We received sorbitol-MacConkey agar plates from every stool culture performed at both sites during 2000-2006. Colony sweeps were screened for stx1 and stx2 by polymerase chain reaction. E. coli identity, serotype, and presence of stx1 and/or stx2 were confirmed on individual isolates. RESULTS: Two hundred six STEC isolates were identified: 108 (52%) were non-O157 serotypes, and 98 (48%) were O157. Of non-O157 cases, 54% involved bloody diarrhea, and 8% involved hospitalization. Non-O157 isolates with at least stx2 were not more likely to cause severe illness (bloody diarrhea, hospitalization, or HUS) than were non-O157 isolates with only stx1. O157 cases were more likely than non-O157 cases to involve bloody diarrhea (78% vs 54%; P < .001), hospitalization (34% vs 8%; P < .001 and HUS (7% vs 0%; P = .005). When including only isolates with at least stx2, O157 cases were still more likely to involve bloody diarrhea (78% vs 56%; P = .02) and hospitalization (33% vs 12%; P = .01) than non-O157 cases. CONCLUSIONS: Differences in severity among STEC infections could not be explained by stx2, suggesting that additional factors are important in STEC virulence.

A community outbreak of conjunctivitis caused by nontypeable Streptococcus pneumoniae in Minnesota.

BACKGROUND: The Minnesota Department of Health (MDH) was notified of an outbreak of conjunctivitis in city A with cultures positive for Streptococcus pneumoniae. METHODS: MDH staff contacted clinics and schools in city A and city B regarding conjunctivitis cases, reviewed clinical findings of conjunctivitis cases in city A and collected isolates for subtyping. RESULTS: Between September 1 and December 12, 2003, cities A and B reported 735 conjunctivitis cases. Fifty-one percent of the cases were reported from schools, childcare centers and colleges. Adults were more likely to report itching, burning or swelling of the eye(s); children were more likely to report crusty eyes (P < 0.05). Forty-nine percent of conjunctival cultures (71 of 144) were positive for S. pneumoniae. All isolates were nontypeable by serotyping. Pulsed field gel electrophoresis identified 3 clonal groups with 84% of isolates belonging to one clonal group. Multilocus sequence typing revealed that isolates had the same multilocus sequence type as isolates from a 2002 outbreak at a New England college. CONCLUSIONS: This outbreak was widespread in the community and conjunctivitis clinical presentation varied by age. The predominant strains in this outbreak were related to a pneumococcal strain implicated in prior conjunctivitis outbreaks, suggesting these strains have a predilection for causing conjunctivitis.