Molecular Epidemiology of Infant Botulism in California and Elsewhere, 1976-2010

• Published in: The Journal of infectious diseases Vol. 210; no. 11; pp. 1711 - 1722
• Main Authors: Dabritz, Haydee A., Hill, Karen K., Barash, Jason R., Ticknor, Lawrence O., Helma, Charles H., Dover, Nir, Payne, Jessica R., Arnon, Stephen S.
• Format: Journal Article
• Language: English
• Published: Oxford Oxford University Press 01-12-2014
• Subjects: Amplified Fragment Length Polymorphism Analysis; BACTERIA; Bacterial diseases; Bacterial diseases of the nervous system. Bacterial myositis; Biological and medical sciences; Botulinum Toxins - genetics; Botulism; Botulism - epidemiology; Botulism - history; California - epidemiology; Clostridium botulinum; Clostridium botulinum - classification; Clostridium botulinum - genetics; Clostridium botulinum - isolation & purification; Fundamental and applied biological sciences. Psychology; Genotype; Geography; History, 20th Century; History, 21st Century; Honey; Human bacterial diseases; Humans; Incidence; Infant; Infectious diseases; Medical sciences; Microbiology; Molecular epidemiology; Neurotoxins; Phylogeny; Phylogeography; Public Health Surveillance; Reverse transcriptase polymerase chain reaction; Spores; Toxins; Valleys; California; United States; North America; America; Human; Infection; Botulism; Bacteriosis; Molecular epidemiology; Genotype; Infant; botulinum toxin; molecular epidemiology; Clostridium botulinum; sudden infant death; Clostridium butyricum; clinical spectrum; Clostridium baratii; honey; infant botulism
• ISSN: 0022-1899; 1537-6613
• DOI: 10.1093/infdis/jiu331

Background, Infant botulism (IB), first identified in California in 1976, results from Clostridium botulinum spores that germinate, multiply, and produce botulinum neurotoxin (BoNT) in the immature intestine. From 1976 to 2010 we created an archive of 1090 BoNT-producing isolates consisting of 1012 IB patient (10 outpatient, 985 hospitalized, 17 sudden death), 25 food, 18 dust/soils, and 35 other strains. Methods. The mouse neutralization assay determined isolate toxin type (56% BoNT/A, 32% BoNT/B). Amplified fragment-length polymorphism (AFLP) analysis of the isolates was combined with epidemiologic information. Results. The AFLP dendrogram, the largest to date, contained 154 clades; 52% of isolates clustered in just 2 clades, 1 BoNT/A (n = 418) and 1 BoNT/B (n = 145). These clades constituted an endemic C. botulinum population that produced the entire clinical spectrum of IB. Isolates from the patient's home environment (dust/soil, honey) usually located to the same AFLP clade as the patient's isolate, thereby identifying the likely source of infective spores. C. botulinum A(B) strains were identified in California for the first time. Conclusions. Combining molecular methods and epidemiological data created an effective tool that yielded novel insights into the genetic diversity of C. botulinum and the clinical spectrum, occurrence, and distribution of IB in California.