Bacterial infectious diseases are a class of diseases with specific pathogens. Current studies have shown the important application and signal transduction mechanism of exosomes in bacterial infectious diseases, but the studies are still limited. Therefore, the relationship between exosomes and bacterial infectious diseases should be further explored to provide new diagnosis and treatment ideas for clinicians. This paper reviews the mechanism and prospect of exosomes in bacterial infectious diseases caused by different pathogens. It summarizes the biological characteristics of exosomes. The mechanisms of bacterial infectious diseases, the primary pathways through which exosomes regulate various pathogens, and the modification of exosomes for anti-infection.
Humans ; Exosomes/metabolism* ; Signal Transduction ; Bacterial Infections/metabolism* ; Communicable Diseases

Animals ; Bacterial Infections/metabolism* ; Glucose/metabolism* ; Homeostasis ; Insulin Secretion ; Mice ; Mice, Knockout ; Sirtuins/metabolism*

Autophagy is a housekeeping process that maintains cellular homeostasis through recycling of nutrients and degradation of damaged or aged cytoplasmic constituents. Over the past several years, accumulating evidence has suggested that autophagy can function as an intracellular innate defense pathway in response to infection with a variety of bacteria and viruses. Autophagy plays a role as a specialized immunologic effector and regulates innate immunity to exert antimicrobial defense mechanisms. Numerous bacterial pathogens have developed the ability to invade host cells or to subvert host autophagy to establish a persistent infection. In this review, we have summarized the recent advances in our understanding of the interaction between antibacterial autophagy (xenophagy) and different bacterial pathogens.
Animals ; Autophagy/*physiology ; Bacterial Infections/*immunology/metabolism ; Humans ; Immunity, Innate/physiology ; Reactive Oxygen Species/metabolism

OBJECTIVETo investigate whether the presence of structured CagA proteins in Western- and Eastern-type Helicobacter pylori (H. pylori) induces different incidences of gastric diseases.

METHODSCagA and phosphorylated CagA were expressed in AGS gastric epithelial cells infected with wild type and mutant strains. The ability of individual CagA was determined by immunoprecipitation and Western blot assay. Morphological changes of these cells were observed under microscope to evaluate the appearance of elongation hummingbird phenotype.

RESULTSThe sizes of CagA proteins in different strains were different, and no phosphorylated CagA proteins were detected in wild-type strains. Meanwhile, the kinetics of CagA status in AGS infected with H. pylori was detected. The molecular weight of phosphorylated CagA with the same size of CagA proteins in H. pylori was different in infections with different wild-type strains. CagA and phosphorylated CagA increased in a time-dependent manner after the infection. The hummingbird phenotype with H. pylori for time-course was observed under microscope. Instead of HPK5 strain, the wild-type 26695 strain induced hummingbird phenotype in a time-dependent manner.

CONCLUSIONTranslocation and phosphorylation of CagA are necessary, but not sufficient, for the induction of hummingbird phenotype in AGS cells.

Amino Acid Sequence ; Antigens, Bacterial ; metabolism ; Bacterial Proteins ; metabolism ; Cell Line ; Helicobacter Infections ; metabolism ; microbiology ; Helicobacter pylori ; Humans ; Interleukin-1 ; genetics ; metabolism ; Protein Transport

OBJECTIVETo study the clinical significance of virulence genes exo U and exo S of type III secretion system (TTSS) of Pseudomonas aeruginosa (PA).

METHODSOne hundred and eighty-nine clinical isolates of PA were collected from five hospitals. The incidence of virulence genes exo U and exo S in PA were determined with PCR. Minimum inhibitory concentration of anti-bacterial drug for PA was determined with microdilution method. The clinical features and outcomes of 60 hospitalized patients colonized or infected with exo U+/exo S- positive or exo U-/exo S+ positive PA isolated from sputum were analyzed retrospectively. Data were processed with chi-square test.

RESULTSAmong the 189 PA isolates, 85.2% (161/189) harbored TTSS genes, including exo U-/exo S+ type (120 isolates), exo U+/exo S- type (31 isolates), exo U-/exo S- type (7 isolates), and exo U+/exo S+ type (3 isolates). 72.0% (72/100) isolates from sputum and 81.5% (44/54) isolates from blood belonged to exo U-/exo S+ genotype. Compared with those of TTSS-negative isolates, the antimicrobial resistance of TTSS-positive isolates to cefoperazone/sulbactam, ceftazidime, amikacin, and cefepime were lower (with χ² value respectively 10.1, 16.1, 9.3, 33.8, P values all below 0.01). The antimicrobial resistance to all examined drug between exo U-/exo S+ type and exo U+/exo S- type isolates was close (with χ² values from 0.08 to 2.04, P values all above 0.05). Patients detected with exo U+/exo S- positive PA isolated from sputum were significantly associated with PA infection, and they usually had history of tracheal intubation, ICU hospitalization, and combined use of drugs for anti-infection treatment. Patients detected with exo U-/exo S+ positive PA isolated from sputum were significantly associated with PA colonization, which had basic lung disease and better outcome than the former infection type.

CONCLUSIONSThe TTSS exists in most clinical isolates of PA. Detection of exo U or exo S of PA isolated from sputum is helpful for the analysis of clinical features and outcome of patients.

ADP Ribose Transferases ; genetics ; metabolism ; Bacterial Proteins ; genetics ; metabolism ; Bacterial Secretion Systems ; genetics ; Bacterial Toxins ; genetics ; metabolism ; Drug Resistance, Bacterial ; Genes, Bacterial ; Humans ; Microbial Sensitivity Tests ; Pseudomonas Infections ; microbiology ; Pseudomonas aeruginosa ; genetics ; isolation & purification ; pathogenicity ; Retrospective Studies ; Virulence

This article reviews the production, metabolism, and clinical application of procalcitonin (PCT). PCT is a useful indicator to differentiate bacterial infection and virus infection. Also, it can be used to determine the infection severity and prognosis.
Animals ; Bacterial Infections ; immunology ; Calcitonin ; genetics ; metabolism ; Calcitonin Gene-Related Peptide ; Humans ; Protein Precursors ; genetics ; metabolism ; Virus Diseases ; metabolism

OBJECTIVETo identify antigenic proteins secreted by Streptococcus suis (S. suis) type 2 strain SC84.

METHODSTwo-dimensional electrophoresis (2-DE), western-blot assay and matrix-assisted laser desorption/ionization-time of flight-mass spectrometry (MALDI-TOF-MS) analysis were performed to search and identify antigenic proteins secreted by S. suis strain SC84, which triggered an outbreak of the disease in Sichuan province,China, in 2005.

RESULTSA total number of 14 western blot spots were found on PVDF membrane. 11 spots which could be found the existence of matching protein on coomassie G-250-stained 2-DE gel were identified by MALDI-TOF MS. The 11 proteins, all located at extra-cellular or cell wall, were classified into 8 kinds of proteins. Among of them, muramidase-released protein (MRP), suilysin (Sly) and extra-cellular factor (EF) were the known antigenic proteins, but several proteins such as putative 5'-nucleotidase, ribo-nucleases G and E, and predicted metal-loendo-peptidase were newly found antigenic proteins. All the identified protein were found to have had the coding gene in genomic of S. suis strain 05ZYH33, isolated from patients in Sichuan province, China in 2005.

CONCLUSIONThe newly found proteins could be used as voluntary antigens for detection and vaccination of S. suis.

Bacterial Proteins ; analysis ; immunology ; Humans ; Proteomics ; Streptococcal Infections ; Streptococcus suis ; immunology ; isolation & purification ; metabolism

Bacterial Infections ; drug therapy ; metabolism ; Biomarkers ; analysis ; Clinical Trials as Topic ; Humans ; Infant, Newborn ; Neonatology ; Research Report

Anti-Bacterial Agents ; administration & dosage ; adverse effects ; therapeutic use ; Bacteria ; drug effects ; metabolism ; Bacterial Infections ; drug therapy ; Drug Resistance, Bacterial ; drug effects ; Humans ; Infant, Newborn ; Superinfection ; drug therapy

OBJECTIVETo investigate the production and AmpC β-lactamase in Klebsiella (K.) pneumoniae resulting in respiratory infections in children, AmpC β-Lactamase genotypic resistance and typical resistance to common antibiotics so as to provide some references for selecting drugs in clinical treatment.

METHODMicrobiological identification was performed with the VITEK 60 System, extended spectrum β lactamases (ESBLs) were detected in accordance with the confirmatory test recommended by Clinical and Laboratory Standards Institute (CLSI) and drug sensitivity was determined with Kirby-Bauer method. Suspected positive strains of AmpC β-lactamase were screened with cefoxitin disk diffusion. The genotypes were analyzed by cefoxitin three-dimensional test, conjugation test and PCR sequencing.

RESULTOf the 135 isolates, 30.37% were ESBLs positive, 15.56% were AmpC β-lactamase positive. The positive rates for only AmpC β-Lactamase, both AmpC β-Lactamase and ESBLs, and only ESBLs were 8.15%, 7.41% and 22.96% respectively. The resistant genotypes for AmpC β-Lactamase-positive strains was that 19 strains were of DHA-1 type and 2 were of ACT-1 type. The resistance to drugs in β-lactamase-producing strains was obviously higher than that in non-β-lactamase-producing strains and more serious in those strains producing both AmpC β-Lactamase and ESBLs. Sensitivity of β-lactamase, non-β-lactamase and ESBLs producing strains to imipenem was as high as 100 percent.

CONCLUSIONESBLs- and AmpC-β-lactamase-producing strains of K. pneumoniae resulting in respiratory infections in children in Taizhou city, have a higher detection rate in Taizhou and AmpC-β-lactamase is mainly of DHA-1 genotype. AmpC-β-lactamase- and ESBLs-producing strains are highly resistant, so to restrict the use of β-lactam antibiotics is an important step to reduce the epidemic of β-lactamase-producing strains infection.

Bacterial Proteins ; metabolism ; Child ; Drug Resistance, Multiple, Bacterial ; Genome, Bacterial ; Genotype ; Humans ; Klebsiella Infections ; microbiology ; Klebsiella pneumoniae ; drug effects ; enzymology ; genetics ; Microbial Sensitivity Tests ; Plasmids ; Respiratory Tract Infections ; microbiology ; beta-Lactamases ; metabolism