RESUMO
Fourier transform infrared spectroscopy (FTIRS) is a diagnostic technique historically used in the microbiological field for the characterization of bacterial strains in relation to the specific composition of their lipid, protein, and polysaccharide components. For each bacterial strain, it is possible to obtain a unique absorption spectrum that represents the fingerprint obtained based on the components of the outer cell membrane. In this study, FTIRS was applied for the first time as an experimental diagnostic tool for the discrimination of two pathogenic species belonging to the Bacillus cereus group, Bacillus anthracis and Bacillus cereus sensu stricto; these are two closely related species that are not so easy to differentiate using classical microbiological methods, representing an innovative technology in the field of animal health.
RESUMO
In 2011, in Bangladesh, 11 anthrax outbreaks occurred in six districts of the country. Different types of samples were collected from May to September in the six districts where anthrax had occurred in order to detect and type Bacillus anthracis (B. anthracis) strains. Anthrax was detected in 46.6% of the samples analysed, in particular in soils, but also in bone samples, water, animal feed, and rumen ingesta of dead animals. Canonical single nucleotide polymorphisms (CanSNPs) analysis showed that all the isolates belonged to the major lineage A, sublineage A.Br.001/002 of China and Southeast Asia while the multi-locus variable number of tandem repeats (VNTRs) analysis (MLVA) with 15 VNTRs demonstrated the presence of five genotypes, of which two resulted to be new genotypes. The single nucleotide repeats (SNRs) analysis showed 13 SNR types; nevertheless, due to its higher discriminatory power, the presence of two isolates with different SNR-type polymorphisms was detected within two MLVA genotypes. This study assumes that soil is not the only reason for the spread of the disease in Bangladesh; contaminated feed and water can also play an important role in the epidemiology of anthrax. Possible explanations for these epidemiological relationships are discussed.
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Matrix-Assisted Laser Desorption/Ionization Time Of Flight Mass Spectrometry (MALDI-TOF MS) technology is currently increasingly used in diagnostic laboratories as a cost effective, rapid and reliable routine technique for the identification and typing of microorganisms. In this study, we used MALDI-TOF MS to analyze a collection of 160 strains belonging to the Bacillus cereus group (57 B. anthracis, 49 B. cereus, 1 B. mycoides, 18 B. wiedmannii, 27 B. thuringiensis, 7 B. toyonensis and 1 B. weihenstephanensis) and to detect specific biomarkers which would allow an unequivocal identification. The Main Spectra Profiles (MSPs) were added to an in-house reference library, expanding the current commercial library which does not include B. toyonensis and B. wiedmannii mass spectra. The obtained mass spectra were statistically compared by Principal Component Analysis (PCA) that revealed seven different clusters. Moreover, for the identification purpose, were generated dedicate algorithms for a rapid and automatic detection of characteristic ion peaks after the mass spectra acquisition. The presence of specific biomarkers can be used to differentiate strains within the B. cereus group and to make a reliable identification of Bacillus anthracis, etiologic agent of anthrax, which is the most pathogenic and feared bacterium of the group. This could offer a critical time advantage for the diagnosis and for the clinical management of human anthrax even in case of bioterror attacks.
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This report describes the evolution of COVID-19 in a 10 day-old-baby. The mother developed the disease immediately after childbirth and therefore a vertical transmission can be excluded. The isolation of the virus in cell culture with a cytopathic effect already visible after 48 h, indicates that the viral load of the newborn was quite high, but not serious course of the disease was observed. This paper wants to highlight the possible role of newborns and children in the spread of the disease.
RESUMO
The use of products that can neutralize or significantly reduce the microbial load and that are not harmful to human health and the environment represents a milestone in the fight against the spread of infectious diseases. Peracetic acid, besides being an excellent sterilizing and sporicidal agent, is harmless to humans and the environment when it is used in a common dosage. However, the high costs and loss of efficacy of the product very quickly after its reconstitution limit its use. We evaluated the efficacy and stability of 2 commercial products, based on stabilized peracetic acid (Pathoster(®) 0.35% and Pathoster(®) 0.50%) used against spores of Bacillus anthracis and spores of Bacillus cereus and vegetative forms of Yersinia pestis, Burkholderia mallei, Burkholderia pseudomallei, Francisella tularensis, Brucella abortus, and Brucella melitensis. The efficacy tests were based on the direct contact of the products with a standard suspension of the bacteria. The stability of the products was defined as the period of time during which the biocidal and sporicidal properties remained unchanged. The limit of effectiveness was the period after which the product was unable to exert a complete sterilization after a contact of 5 minutes with at least 1 of the 8 bacteria used in this work. Both formulations showed good efficacy against the microorganisms used in the study, confirming the utility of peracetic acid as a sterilizing product. After the reconstitution, Pathoster(®) 0.35% was stable until 16±1 days, while Pathoster(®) 0.50% was stable until 24±1 days. The formulations used in this study showed good performance and a significant stability of peracetic acid.
Assuntos
Bactérias/efeitos dos fármacos , Ácido Peracético/farmacologia , Esporos Bacterianos/efeitos dos fármacos , Bioterrorismo/prevenção & controle , Desinfetantes/química , Ácido Peracético/químicaRESUMO
A Bacillus anthracis strain was isolated from a burial-site in Pollino National Park where a bovine died of anthrax and was buried in 2004. We report the first genome sequence of B. anthracis isolated in the Basilicata region (southern Italy), which is the highest risk area of anthrax infection in Italy.