Complete genome sequences of strains ASE2 and ASE4 generated by PacBio sequencing.

strains ASE2 and ASE4 were isolated from the soil of a lettuce farm in Salinas, California, in 2020. Their complete genome sequences were generated by the PacBio Sequel II platform. They both consist of a single circular chromosome without plasmids.

Biocontrol of Escherichia coli O157:H7 by Enterobacter asburiae AEB30 on intact cantaloupe melons.

Escherichia coli O157:H7 causes >73,000 foodborne illnesses in the United States annually, many of which have been associated with fresh ready-to-eat produce including cantaloupe melons. In this study, we created a produce-associated bacterial (PAB) library containing >7500 isolates and screened them for the ability to inhibit the growth of E. coli O157:H7 using an in vitro fluorescence-based growth assay.

Complete genome sequence of ASE1 generated by PacBio sequencing.

We report the complete genome sequence of ASE1 generated by the PacBio Sequel II platform. This bacterium was isolated from the soil of a lettuce farm in Salinas, CA, USA, in 2020. The genome consists of a single circular chromosome of 5,021,820 bp with a 52.

Use of Pantoea agglomerans ASB05 as a biocontrol agent to inhibit the growth of Salmonella enterica on intact cantaloupe melons.

Aims: To identify biocontrol agents to prevent the growth of Salmonella serotype Enterica on cantaloupe melons during the pre- and postharvest periods.

Methods And Results: We created a produce-associated bacterial library containing 8736 isolates and screened it using an in-vitro fluorescence inhibition assay to identify bacteria that inhibit the growth of S. Enterica.

Complete Genome Sequence of Enterobacter asburiae Strain AEB30, Determined Using Illumina and PacBio Sequencing.

The complete genome sequence of Enterobacter asburiae strain AEB30 is presented. The strain was isolated from store-bought ginger in Albany, CA, in 2016.

Complete Genome Sequence of Pantoea agglomerans ASB05 Using Illumina and PacBio Sequencing.

We present the complete genome sequence of Pantoea agglomerans ASB05 and three associated plasmids, generated using a combination of the Illumina and PacBio platforms. ASB05 was isolated from fresh cherries purchased in Albany, CA, in 2016.

ALB65 Inhibits the Growth of on Cantaloupe Melons.

is a foodborne pathogen that causes high rates of hospitalization and mortality in people infected. Contamination of fresh, ready to eat produce by this pathogen is especially troubling because of the ability of this bacterium to grow on produce under refrigeration temperatures. In this study, we created a library of over 8,000 plant phyllosphere-associated bacteria and screened them for the ability to inhibit the growth of in an fluorescence-based assay.

Complete Genomic Sequences of Three Salmonella enterica subsp. Serovar Muenchen Strains from an Orchard in San Joaquin County, California.

We present here the complete genome sequences of three subsp. serovar Muenchen strains, LG24, LG25, and LG26. All three strains were isolated from almond drupes grown in an orchard in San Joaquin County, California, in 2016.

Use of Phyllosphere-Associated Lactic Acid Bacteria as Biocontrol Agents To Reduce Serovar Poona Growth on Cantaloupe Melons.

Foodborne illness associated with fresh, ready-to-eat produce continues to be a significant challenge to public health. In this study, we created a phyllosphere-associated lactic acid bacteria (PLAB) library and screened it via a high-throughput in vitro fluorescent assay to identify bacteria capable of inhibiting the growth of the pathogenic bacterium . One isolate, 14B4, inhibited the growth of by >45-fold in vitro; it was able to grow and persist on the surfaces of cantaloupe melons at both ambient (25°C) and refrigerator (5°C) temperatures.

Complete Genome Sequence of Lactococcus lactis subsp Strain 14B4, Which Inhibits the Growth of Salmonella enterica Serotype Poona .

We present here the complete genome sequence of Lactococcus lactis strain 14B4, isolated from almond drupes in northern California. This strain was observed to inhibit the growth of Salmonella enterica serotype Poona strain RM3363 .

Induction of the pneumococcal vncRS operon by lactoferrin is essential for pneumonia.

Streptococcus pneumoniae (pneumococcus), the major pathogen for pneumonia, commonly colonizes the lung, but the mechanism underlying the coordination of virulence factors during invasion via the host protein remains poorly understood. Bacterial lysis releases the components of the cell wall, and triggers innate immunity and the subsequent secretion of pro-inflammatory cytokines. Previously, the virulence of the pep27 mutant was shown to be attenuated as a feasible candidate for vaccine development.

Complete Genome Sequences of Three Bacillus amyloliquefaciens Strains That Inhibit the Growth of Listeria monocytogenes .

Here, we report the complete genome sequences of three strains isolated from alfalfa, almond drupes, and grapes that inhibited the growth of strain 2011L-2857 We also report multiple gene clusters encoding secondary metabolites that may be responsible for the growth inhibition of .

ClpL is a chaperone without auxiliary factors.

Caseinolytic protease L (ClpL) is a member of the heat shock protein (Hsp) 100 family, which is found mostly in Gram-positive bacteria. Here, ClpL, a major HSP in Streptococcus pneumoniae (pneumococcus), was biochemically characterized in vitro. Recombinant ClpL shows nucleotide hydrolase, refolding, holdase and disaggregation activity using either Mg(2+) or Mn(2+) and does not require the DnaK system for chaperone activity.

Streptococcus pneumoniae ClpL modulates adherence to A549 human lung cells through Rap1/Rac1 activation.

Caseinolytic protease L (ClpL) is a member of the HSP100/Clp chaperone family, which is found mainly in Gram-positive bacteria. ClpL is highly expressed during infection for refolding of stress-induced denatured proteins, some of which are important for adherence. However, the role of ClpL in modulating pneumococcal virulence is poorly understood.

Inactivated pep27 mutant as an effective mucosal vaccine against a secondary lethal pneumococcal challenge in mice.

Purpose: A pep27 mutant may be able to elicit mucosal immunity against pneumococcal diseases, and could be employed as an inexpensive attenuated vaccine. However, this particular mutant contains an erythromycin-resistance marker. The purpose of the current study is to develop a markerless pep27 mutant and assess whether this inactivated mutant is able to induce mucosal immunity.

Streptococcus pneumoniae pep27 mutant as a live vaccine for serotype-independent protection in mice.

Streptococcus pneumoniae (pneumococcus) is responsible for significant morbidity and mortality in worldwide. After introduction of current pneumococcal vaccines, a marked decrease in the incidence of pneumococcal disease was observed. Unfortunately, serotype shifts in carriage and disease, including capsular switch and presence of antimicrobial resistance, have been found.

Heat-shock protein ClpL/HSP100 increases penicillin tolerance in Streptococcus pneumoniae.

Penicillin resistance and tolerance has been an increasing threat to the treatment of pneumococcal pneumoniae. However, no penicillin tolerance-related genes have been claimed. Here we show that a major heat shock protein ClpL/HSP100 could modulate the expression of a cell wall synthesis enzyme PBP2x, and subsequently increase cell wall thickness and penicillin tolerance in Streptococus pneumoniae.

Decrease in penicillin susceptibility due to heat shock protein ClpL in Streptococcus pneumoniae.

Antibiotic resistance and tolerance are increasing threats to global health as antibiotic-resistant bacteria can cause severe morbidity and mortality and can increase treatment cost 10-fold. Although several genes contributing to antibiotic tolerance among pneumococci have been identified, we report here that ClpL, a major heat shock protein, could modulate cell wall biosynthetic enzymes and lead to decreased penicillin susceptibility. On capsular type 1, 2, and 19 genetic backgrounds, mutants lacking ClpL were more susceptible to penicillin and had thinner cell walls than the parental strains, whereas a ClpL-overexpressing strain showed a higher resistance to penicillin and a thicker cell wall.

Virulence attenuation of Streptococcus pneumoniae clpP mutant by sensitivity to oxidative stress in macrophages via an NO-mediated pathway.

ClpP protease is essential for virulence and survival under stress conditions in several pathogenic bacteria. The clpP mutation in a murine infection model has demonstrated both attenuation of virulence and a sensitivity to hydrogen peroxide. However, the underlying mechanisms for these changes have not been resolved.

Reduction-sensitive and cysteine residue-mediated Streptococcus pneumoniae HrcA oligomerization in vitro.

In both gram-positive and several gram-negative bacteria, the transcription of dnaK and groE operons is negatively regulated by HrcA; however, the mechanism modulating HrcA protein activity upon thermal stress remains elusive. Here, we demonstrate that HrcA is modulated via reduction and oligomerization in vitro. Native-PAGE analysis was used to reveal the oligomeric structure of HrcA.