A novel method was developed to rapidly concentrate, detect, and differentiate bacteria in skimmed milk using surface enhanced Raman scattering (SERS) mapping on 4-mercaptophenylboronic acid (4-MPBA) functionalized silver (Ag) dendrites. The 4-MPBA functionalized Ag dendritic SERS substrate was used to capture the bacterial cells and enhance the bacterial signal. Salmonella, a significantly important food pathogen, was used as the representative strain to optimize and evaluate the developed method. The capture efficiency for Salmonella enterica subsp enterica BAA1045 (SE1045) was 84.92 ± 3.25% at 10 CFU/mL and as high as 99.65 ± 3.58% at 10 CFU/mL. Four different strains, two gram-negative and two gram-positive, can be clearly distinguished by their SERS spectra using principle component analysis. A mapping technique was utilized to automatically collect 400 spectra over an area of 60 μm × 60 μm to construct a visual image for a sensitive and statistically reliable detection within 30 min. Using this method, we were able to detect as low as 10 CFU/mL bacterial cells in 50 mM NHHCO solution and 10 CFU/mL cells in both 1% casein and skimmed milk. Our results demonstrate the feasibility of using SERS mapping method coupled with 4-MPBA functionalized Ag dendrites for rapid and sensitive bacteria detection in complex liquid samples. Graphical Abstract A novel SERS mapping method based on 4-mercaptophenylboronic acid functionalized silver (Ag) dendrites was developed to rapidly concentrate, detect, and differentiate bacteria.

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Reaerosolization or resuspension-that is, the reintroduction of previously airborne particles into the atmosphere-is a complex phenomenon. Microbial reaerosolization is particularly poorly understood because few studies have been done in this area, and many of the studies that have been performed are not in the peer-reviewed literature. The reaerosolization of Bacillus anthracis in outdoor environments is of particular concern because of its stability and potential for use as a biological weapon. This review pulls together data from more than 30 publications, spanning field and laboratory experiments, to summarize the current state of our understanding of Bacillus spp. reaerosolization in outdoor environments.

The increased incidence of food pathogen outbreaks placed a new emphasis on the requirement of a rapid, sensitive, and reliable detection method for pathogens in food samples.