Association Between Caseload Surge and COVID-19 Survival in 558 U.S. Hospitals, March to August 2020.

Background: Several U.S. hospitals had surges in COVID-19 caseload, but their effect on COVID-19 survival rates remains unclear, especially independent of temporal changes in survival.

SatS is a chaperone for the SecA2 protein export pathway.

The SecA2 protein export system is critical for the virulence of . However, the mechanism of this export pathway remains unclear. Through a screen for suppressors of a mutant, we identified a new player in the mycobacterial SecA2 pathway that we named SatS for ec2 (wo) uppressor.

An orphaned Mce-associated membrane protein of Mycobacterium tuberculosis is a virulence factor that stabilizes Mce transporters.

Mycobacterium tuberculosis proteins that are exported out of the bacterial cytoplasm are ideally positioned to be virulence factors; however, the functions of individual exported proteins remain largely unknown. Previous studies identified Rv0199 as an exported membrane protein of unknown function. Here, we characterized the role of Rv0199 in M.

Correlation between GyrA substitutions and ofloxacin, levofloxacin, and moxifloxacin cross-resistance in Mycobacterium tuberculosis.

The newer fluoroquinolones moxifloxacin (MXF) and levofloxacin (LVX) are becoming more common components of tuberculosis (TB) treatment regimens. However, the critical concentrations for testing susceptibility of Mycobacterium tuberculosis to MXF and LVX are not yet well established. Additionally, the degree of cross-resistance between ofloxacin (OFX) and these newer fluoroquinolones has not been thoroughly investigated.

Label-free Quantitative Proteomics Reveals a Role for the Mycobacterium tuberculosis SecA2 Pathway in Exporting Solute Binding Proteins and Mce Transporters to the Cell Wall.

Mycobacterium tuberculosis is an example of a bacterial pathogen with a specialized SecA2-dependent protein export system that contributes to its virulence. Our understanding of the mechanistic basis of SecA2-dependent export and the role(s) of the SecA2 pathway in M. tuberculosis pathogenesis has been hindered by our limited knowledge of the proteins exported by the pathway.

Aminoglycoside cross-resistance in Mycobacterium tuberculosis due to mutations in the 5' untranslated region of whiB7.

Since the discovery of streptomycin's bactericidal activity against Mycobacterium tuberculosis, aminoglycosides have been utilized to treat tuberculosis (TB). Today, the aminoglycosides kanamycin and amikacin are used to treat multidrug-resistant (MDR) TB, and resistance to any of the second-line injectable antibiotics, including kanamycin, amikacin, or capreomycin, is a defining characteristic of extensively drug-resistant (XDR) TB. Resistance to kanamycin and streptomycin is thought to be due to the acquisition of unlinked chromosomal mutations.

New insights into fluoroquinolone resistance in Mycobacterium tuberculosis: functional genetic analysis of gyrA and gyrB mutations.

Fluoroquinolone antibiotics are among the most potent second-line drugs used for treatment of multidrug-resistant tuberculosis (MDR TB), and resistance to this class of antibiotics is one criterion for defining extensively drug resistant tuberculosis (XDR TB). Fluoroquinolone resistance in Mycobacterium tuberculosis has been associated with modification of the quinolone resistance determining region (QRDR) of gyrA. Recent studies suggest that amino acid substitutions in gyrB may also play a crucial role in resistance, but functional genetic studies of these mutations in M.

Microbial activity and diversity in long-term mixed contaminated soils with respect to polyaromatic hydrocarbons and heavy metals.

The co-occurrence of polyaromatic hydrocarbons (PAHs) with heavy metals and their effect on soil microbial activity have not been systematically investigated. In this study a holistic approach was employed by combining physico-chemical, biological and advanced molecular methods to determine the soil microbial activities of long-term mixed contaminated soils collected from a former manufactured gas plant (MGP) site. Concentrations of PAHs in MGP soils ranged from 335 to 8645 mg/kg.

Hydrolysis of fenamiphos and its toxic oxidation products by Microbacterium sp. in pure culture and groundwater.

A bacterium with an exceptional ability to hydrolyse fenamiphos and its toxic oxidation products fenamiphos sulfoxide and fenamiphos sulfone, all possessing POC bond was isolated from soil. Based on 16S rRNA gene determination, this bacterium was putatively identified as Microbacterium esteraromaticum. The phenols (fenamiphos phenol, sulfoxide phenol and sulfone phenol) formed during bacterial hydrolysis resisted further degradation in mineral salts medium and sterile groundwater, but were transitory in non-sterile groundwater due to the catabolism of native microorganisms.

The use of molecular techniques to characterize the microbial communities in contaminated soil and water.

Traditionally, the identification and characterization of microbial communities in contaminated soil and water has previously been limited to those microorganisms that are culturable. The application of molecular techniques to study microbial populations at contaminated sites without the need for culturing has led to the discovery of unique and previously unrecognized microorganisms as well as complex microbial diversity in contaminated soil and water which shows an exciting opportunity for bioremediation strategies. Nucleic acid extraction from contaminated sites and their subsequent amplification by polymerase chain reaction (PCR) has proved extremely useful in assessing the changes in microbial community structure by several microbial community profiling techniques.

Presence and diversity of the beta-lactamase gene in cat and dog staphylococci.

Staphylococci are part of the normal microflora of humans and animals and some are potential pathogens that have become resistant to almost all known antibiotics. Despite the widespread reports of penicillin resistance in cat and dog staphylococci, the mechanism underlying penicillin resistance has not been examined. This study was aimed at investigating the molecular basis of resistance to penicillin in cat and dog staphylococcal isolates that showed phenotypic resistance to beta-lactam antibiotics.

Molecular typing of methicillin-resistant staphylococci isolated from cats and dogs.

Objectives: Methicillin-resistant staphylococci (MRS) isolates from healthy and diseased cats and dogs were characterized by staphylococcal cassette chromosome mec (SCCmec), multilocus sequence typing (MLST) and cassette chromosome recombinase gene (ccrAB) sequencing.

Methods: PCR-directed SCCmec typing was carried out for all MRS isolates and two Staphylococcus aureus and two Staphylococcus epidermidis strains were analysed by MLST. Strains belonging to SCCmec type III and IV were sequenced for their ccrAB gene of allotypes 3 and 2, respectively.

Partial nucleotide sequencing of the mecA genes of Staphylococcus aureus isolates from cats and dogs.

Methicillin-resistant staphylococci (MRS) pose a challenge to clinicians and health administrators in human medicine, but MRS infections in cats and dogs are not perceived as a problem in veterinary medicine. Ten methicillin-resistant staphylococcal isolates obtained from healthy and diseased cats and dogs were subjected to partial DNA sequencing of the mecA gene. Sequence analysis shows that MRS isolates from both healthy and diseased cats and dogs can harbor the mecA gene.