Laboratory Investigation of the First Case of Botulism Caused by Clostridium butyricum Type E Toxin in the United States

Abstract

We report here the laboratory investigation of the first known case of botulism in the United States caused by Clostridium butyricum type E. This investigation demonstrates the importance of extensive microbiological examination of specimens, which resulted in the isolation of this organism. B otulism is a rare but acute paralytic disease caused by botulinum neurotoxin (BoNT). Botulism can occur when contaminated food is ingested (food-borne) or when BoNT-producing clostridia colonize wounds or the intestine. Infant botulism occurs through intestinal colonization by BoNT-producing clostridia and the subsequent in situ production of BoNT in infants (1). Diagnosis is based on clinical presentation (1, 2). In the United States, botulism immune globulin human (intravenous) (BIG-IV) is available for the treatment of infant botulism through the California Department of Public Heath (CDPH) Infant Botulism Treatment and Prevention Program (IBTPP) (2). Laboratory confirmation is performed at the Centers for Disease Control and Prevention (CDC) and state public health laboratories (1, 2).Clostridium botulinum types A and B are the serotypes most frequently associated with infant botulism worldwide, accounting for ϳ98% of reported infant botulism cases (2). Infant botulism caused by C. butyricum type E was first reported in 1987 (3). Since then, this organism has been linked to infant botulism cases in Italy, Japan, the Republic of Ireland, and England (3-6). Additionally, C. butyricum type E has been associated with food-borne botulism in China, Italy, and India (4, 7, 8). We report here the laboratory investigation of the first case in the United States of botulism caused by C. butyricum type E.A stool sample collected from a 7-day-old infant with suspected botulism was submitted to the Centers for Disease Control and Prevention (CDC) National Botulism Laboratory for laboratory testing. The sample was tested for BoNT by mouse bioassay (1). Procedures were conducted in accordance with Association for Assessment and Accreditation of Laboratory Animal Care guidelines and institutionally approved protocols for the ethical use of laboratory animals. The amount of BoNT type E detected in the stool was 126,400 mLD 50 /g (mLD 50 , 50% mouse lethal dose), which is Ͼ150 times higher than that previously reported for type E infant botulism cases (4). The stool sample was cultured for the growth of BoNT-producing clostridia using standard laboratory methods (9). McClung-Toabe egg yolk agar (EYA) plates were streaked for isolation from stool and from enriched broth cultures. Plates were incubated for 2 to 3 days, and broth cultures

Clostridium butyricum : from beneficial to a new emerging pathogen

“…Since then, C. butyricum has been associated with botulism in other countries (i.e. China, India, Japan, Ireland, and the USA) [32]. Notably, the operon encoding the BoNT/E toxin harboured by the neurotoxigenic C. butyricum strains is very similar to that carried by group II type E toxin-producing C. botulinum strains [33].…”

“…Botulism is an acute paralytic disease caused by botulinum neurotoxin (BoNT), which is most frequently secreted by Clostridium botulinum [6]. Botulism can occur when BoNTproducing clostridia colonize wounds or the intestine and subsequently secrete the toxin, or when contaminated food is ingested (foodborne) [32]. In 1986, the first infant botulism case caused by a BoNT/E-producing C. butyricum strain was reported in Italy [6].…”

Type E botulism associated with fish product consumption – Germany and Spain

“…Foodborne botulism outbreaks involving Group II BoNT E have been frequently associated with the consumption of fish and fish products [6,7], probably due to temperature abuse as this group of bacteria is psychrotrophic and grows well in anaerobic, chilled environments [4,6]. While C. botulinum is the most common species producing botulinum neurotoxins, rare cases of BoNT E have been caused by C. butyricum [8].…”

Effects of Megaplasmid Loss on Growth of Neurotoxigenic Clostridium butyricum Strains and Botulinum Neurotoxin Type E Expression

“…Neurotoxigenic C. butyricum type E strains have been isolated from cases of intestinal toxemia botulism in infants and adults in Italy, Japan, USA, Ireland, and UK ( Aureli et al, 1986 ; Fenicia et al, 1999 , 2002 ; Abe et al, 2008 ; Dykes et al, 2015 ; Shelley et al, 2015 ); foodborne botulism cases in China, India and Italy ( Meng et al, 1997 ; Chaudhry et al, 1998 ; Anniballi et al, 2002 ); food and environmental samples (soil and lake shore) in China ( Meng et al, 1997 , 1999 ); and, more recently, from pets (turtles) which were identified as the likely source of infection in two infant botulism cases in Ireland ( Shelley et al, 2015 ).…”