Detection of Bacillus anthracis and Bacillus anthracis-like spores in soil from state of Rio de Janeiro, Brazil

Jacqueline Rs Salgado,Leon Rabinovitch,Maria De Fátima Dos S Gomes,Adriana M Vivoni,Rafael B Rodrigues,Regina Celia Da Sb Allil,Renata C Picão,Marcelo Martins Werneck,Fernanda Baptista De Oliveira Luiz

doi:10.1590/0074-02760200370

Abstract

BACKGROUND Bacillus anthracis is the aetiologic agent of anthrax, a re-emerging, septicaemic, haemorrhagic and lethal disease that affects humans, domestic ruminants and wildlife. Plasmids pXO1 and pXO2 are attributes that confer pathogenicity to B. anthracis strains. This bacterium was used as biological weapon in the World Wars and in the biological attack in the United States of America at 2001. B. anthracis is classified as a Tier 1 bioterrorism agent by the Centers for Diseases Control and Prevention. Anthrax is recognised as a re-emerging disease. Several studies concerning the dynamics of B. anthracis cycle in soil revealed that nonpathogenic B. anthracis strains due to lack of pXO2 plasmid are commonly found in some types of soil.OBJECTIVES This study aimed isolation and identification of B. anthracis spores in soil samples of the state of Rio de Janeiro, Brazil.METHODS Phenotypic and genotypic approaches were used to identify isolates including MALDI-TOF/MS, motility test, susceptibility to gamma phage and penicillin, survey for pag and cap genes as surrogates of pXO1 and pXO2 plasmids, respectively, and sequencing of 16SrRNA-encoding gene. Physicochemical analysis of the soil samples were carried out to describe soil characteristics.FINDINGS We observed the presence of one B. anthracis pXO1+ and pXO2- isolated from clay loam soil; one B. anthracis-like strain pXO1+ and pXO2-isolated from loamy sand; and 10 Bacillus spp. strains sensitive to phage-gamma that need better characterisation to define which their species were recovered from loamy sand.MAIN CONCLUSIONSThis work showed promising results and it was the first study to report results from an active surveillance for B. anthracis in Brazil.

Highlights

Bacillus anthracis is the aetiologic agent of anthrax, a re-emerging, septicaemic, haemorrhagic and lethal disease that affects humans, domestic ruminants and wildlife
Values suggested by the Brazilian Agricultural Research Corporation (EMBRAPA) and the Commission of Soil Fertility of Minas Gerais State (CFSEMG) were used for comparison.[14,15] The definition of soils textural class was based on the Triangle Diagram from the United States Department of Agriculture (USDA).(16)
Isolation and identification of B. anthracis suspected bacteria – Bacterial growth was observed after incubation in aerobiosis

Summary

Introduction

Bacillus anthracis is the aetiologic agent of anthrax, a re-emerging, septicaemic, haemorrhagic and lethal disease that affects humans, domestic ruminants and wildlife. Plasmids pXO1 and pXO2 are attributes that confer pathogenicity to B. anthracis strains. This bacterium was used as biological weapon in the World Wars and in the biological attack in the United States of America at 2001. B. anthracis is classified as a Tier 1 bioterrorism agent by the Centers for Diseases Control and Prevention. Anthrax is recognised as a re-emerging disease. Several studies concerning the dynamics of B. anthracis cycle in soil revealed that nonpathogenic B. anthracis strains due to lack of pXO2 plasmid are commonly found in some types of soil

Objectives

Methods

Results

Conclusion