Bacteremia induced by periodontal infection is an important factor for periodontitis to threaten general health. P. gingivalis DNA/virulence factors have been found in the brain tissues from patients with Alzheimer's disease (AD). The blood-brain barrier (BBB) is essential for keeping toxic substances from entering brain tissues. However, the effect of P. gingivalis bacteremia on BBB permeability and its underlying mechanism remains unclear. In the present study, rats were injected by tail vein with P. gingivalis three times a week for eight weeks to induce bacteremia. An in vitro BBB model infected with P. gingivalis was also established. We found that the infiltration of Evans blue dye and Albumin protein deposition in the rat brain tissues were increased in the rat brain tissues with P. gingivalis bacteremia and P. gingivalis could pass through the in vitro BBB model. Caveolae were detected after P. gingivalis infection in BMECs both in vivo and in vitro. Caveolin-1 (Cav-1) expression was enhanced after P. gingivalis infection. Downregulation of Cav-1 rescued P. gingivalis-enhanced BMECs permeability. We further found P. gingivalis-gingipain could be colocalized with Cav-1 and the strong hydrogen bonding between Cav-1 and arg-specific-gingipain (RgpA) were detected. Moreover, P. gingivalis significantly inhibited the major facilitator superfamily domain containing 2a (Mfsd2a) expression. Mfsd2a overexpression reversed P. gingivalis-increased BMECs permeability and Cav-1 expression. These results revealed that Mfsd2a/Cav-1 mediated transcytosis is a key pathway governing BBB BMECs permeability induced by P. gingivalis, which may contribute to P. gingivalis/virulence factors entrance and the subsequent neurological impairments.
Animals ; Rats ; Bacteremia/metabolism* ; Blood-Brain Barrier/microbiology* ; Caveolin 1/metabolism* ; Gingipain Cysteine Endopeptidases/metabolism* ; Permeability ; Porphyromonas gingivalis/pathogenicity* ; Transcytosis ; Virulence Factors/metabolism*

A 42-yr-old man with hepatitis B virus associated liver cirrhosis was admitted to the emergency room because of multiple seizures, a history of chills and myalgia over the previous 2 weeks, and 3 days of melena. He was febrile with a temperature of 38.0degrees C. There were no symptoms and signs related to the genitourinary system, skin, or joints. Three sets of blood cultures were obtained and oxidase-positive, gram-negative diplococci were detected after 25.9-26.9 hr of incubation in all aerobic vials. The organism was positive for catalase and oxidase, and was identified as Neisseria gonorrhoeae, using a Vitek Neisseria-Haemophilus Identification card (bioMerieux Vitek, Inc., USA). Further, 16S rRNA sequencing of this isolate revealed a 99.9% homology with the published sequence of N. gonorrhoeae strain NCTC 83785 (GenBank Accession No. NR_026079.1). Acute bleeding by variceal rupture seems to be a likely route of introduction of N. gonorrhoeae from the mucosa into the blood. To the best of our knowledge, this is the first case of gonococcal bacteremia in Korea.
Adult ; Bacteremia/complications/*diagnosis/microbiology ; Catalase/metabolism ; Esophageal and Gastric Varices/complications/*diagnosis ; Gastrointestinal Hemorrhage/*etiology ; Gonorrhea/complications/*diagnosis/microbiology ; Humans ; Ligation ; Liver Cirrhosis/diagnosis ; Male ; Neisseria gonorrhoeae/genetics/*isolation & purification ; Oxidoreductases/metabolism ; RNA, Ribosomal, 16S/chemistry/genetics ; Sequence Analysis, DNA

This study was purposed to evaluate the diagnostic value of procalcitonin (PCT), C-reactive protein, interleukin-6 (IL-6), serum amyloid A (SAA) for bacteremia in patients with hematologic malignancy combined with febrile neutropenia. The total of 297 patients with hematologic malignancy combined with febrile neutropenia were analyzed retrospectively from 1253 patients admitted to West China hospital of Sichuan University from March 2011 to October 2012. They were divided into sepsis group (n = 95) and non-sepsis group (n = 202) according to blood culture. The results showed that the levels of PCT, CRP, IL-6 and SAA in sepsis group were higher than those in non-sepsis group, and there was statistically significant difference between these two groups (P < 0.05). The PCT had an AUC value of 0.974 (P < 0.05), and obviously higher than that of CRP (AUC = 0.681, P < 0.05), IL-6 (AUC = 0.661, P < 0.05) and SAA (AUC = 0.605, P < 0.05). When PCT had cut-off value of 1.06 ng/ml, sensitivity of 95.8%, specificity of 92.1%, and the Youden indicator of 0.879, the negative and positive predictive values were 97.8% and 85.0% respectively, the negative and positive likelihood ratios were 0.05 and 12.5 respectively, and all significantly higher than that of CRP, IL-6 and SAA. It is concluded that for patients with hematologic malignancy combined with febrile neutropenia and bacterial infection, the diagnostic value of serum PCT is superior to that of immune inflammatory factors (CRP, IL-6 and SAA), the PCT can predict the bacterium infection, provide laboratory evidence for rational antimicrobial drug usage and mortality reduction.
Adult ; Bacteremia ; diagnosis ; etiology ; C-Reactive Protein ; metabolism ; Calcitonin ; blood ; Calcitonin Gene-Related Peptide ; Febrile Neutropenia ; complications ; microbiology ; Female ; Hematologic Neoplasms ; complications ; microbiology ; Humans ; Interleukin-6 ; blood ; Male ; Middle Aged ; Protein Precursors ; blood ; Retrospective Studies ; Serum Amyloid A Protein ; metabolism

No abstract available.
Anti-Bacterial Agents/pharmacology/therapeutic use ; Bacteremia/*diagnosis/drug therapy/microbiology ; Clostridium tertium/drug effects/isolation & purification/*metabolism ; Humans ; Male ; Microbial Sensitivity Tests ; Middle Aged ; *Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization

OBJECTIVETo study the genotype distribution of extended-spectrum beta-lactamases (ESBLs) in ESBLs-producing Escherichia coli (E. coli) isolates from posthepatitic cirrhosis' patients with bloodstream infection.

METHODSE. coli were isolated in bloodstream from patients with posthepatitic cirrhosis between January and December in 2011. The strains were identified by VITEK-II. The antibiol susceptibility tests were performed with K-B method. beta-lactamases genes were detected multi-PCR, PCR, sequence and blast.

RESULTSA total of 79 non-duplicate clinical isolates of E coli were consecutively collected from liver cirrhosis' patients with bloodstream infection. There were 20 isolates produced TEM-1 type beta-lactamases and 1 isolate produced SHV-1 typebeta-lactamases. 40 clinical isolates were detected to produce CTX-M type ESBLs, there were 20 CTX-M-1 group and 26 CTX-M-9 group, including 6 stains habouring both CTX-M-1 and CTX-M-9 group. Eight CTX-M genotypes were confirmed by sequencing of the PCR products, including CTX-M-3, CTX-M-14, CTX-M-15, CTX-M-24, CTX-M-28, CTX-M-31, CTX-M-65 and CTX-M-79.

CONCLUSIONCTX-M genotype ESBLs was the most popular extended-spectrum beta-lactamases in E. coli isolated from liver cirrhosis' patients with bloodstream infection. The CTX-M-14 is the dominant epidemic type.

Bacteremia ; microbiology ; Cross Infection ; microbiology ; Drug Resistance, Bacterial ; Escherichia coli ; drug effects ; enzymology ; genetics ; isolation & purification ; Escherichia coli Infections ; microbiology ; Escherichia coli Proteins ; genetics ; Genotype ; Hospitalization ; statistics & numerical data ; Humans ; Liver Cirrhosis ; therapy ; Microbial Sensitivity Tests ; beta-Lactamases ; genetics ; metabolism

The aim of this study was to develop and validate an oligonucleotide suspension array for rapid identification of 15 bacterial species responsible for bacteremia, particularly prevalent in Chinese hospitals. The multiplexed array, based on the QIAGEN LiquiChip Workstation, included 15 oligonucleotide probes which were covalently bound to different bead sets. PCR amplicons of a variable region of the bacterial 23S rRNA genes were hybridized to the bead-bound probes. Thirty-eight strains belonging to 15 species were correctly identified on the basis of their corresponding species-specific hybridization profiles. The results show that the suspension array, in a single assay, can differentiate isolates over a wide range of strains and species, and suggest the potential utility of suspension array system to clinical laboratory diagnosis.
Bacteremia ; diagnosis ; genetics ; Bacterial Typing Techniques ; Bacteriological Techniques ; DNA Probes ; Genetic Techniques ; Listeria monocytogenes ; metabolism ; Nucleic Acid Hybridization ; Oligonucleotide Array Sequence Analysis ; Oligonucleotides ; chemistry ; RNA, Ribosomal ; chemistry ; RNA, Ribosomal, 23S ; genetics ; Stem Cells

No abstract available.
Aged ; Anti-Bacterial Agents/pharmacology/therapeutic use ; Bacteremia/blood/*diagnosis/microbiology ; C-Reactive Protein/analysis ; Cholecystitis/blood/cerebrospinal fluid/microbiology ; Electrophoresis, Gel, Pulsed-Field ; Enterococcus faecium/drug effects/isolation & purification/metabolism ; Humans ; Male ; Microbial Sensitivity Tests ; Microscopy, Electron, Scanning ; Ochrobactrum/drug effects/isolation & purification/*metabolism ; RNA, Ribosomal, 16S/analysis/genetics/metabolism ; Sequence Analysis, DNA ; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization

Although extended-spectrum beta-lactamase-producing Escherichia coli (ESBL-EC) has emerged as a significant community-acquired pathogen, there is little epidemiological information regarding community-onset bacteremia due to ESBL-EC. A retrospective observational study from 2006 through 2011 was performed to evaluate the epidemiology of community-onset bacteremia caused by ESBL-EC. In a six-year period, the proportion of ESBL-EC responsible for causing community-onset bacteremia had increased significantly, from 3.6% in 2006 to 14.3%, in 2011. Of the 97 clinically evaluable cases with ESBL-EC bacteremia, 32 (33.0%) were further classified as healthcare-associated infections. The most common site of infection was urinary tract infection (n=35, 36.1%), followed by biliary tract infections (n=29, 29.9%). Of the 103 ESBL-EC isolates, 43 (41.7%) produced CTX-M-14 and 36 (35.0%) produced CTX-M-15. In the multilocus sequence typing (MLST) analysis of 76 isolates with CTX-M-14 or -15 type ESBLs, the most prevalent sequence type (ST) was ST131 (n=15, 19.7%), followed by ST405 (n=12, 15.8%) and ST648 (n=8, 10.5%). No significant differences in clinical features were found in the ST131 group versus the other group. These findings suggest that epidemic ESBL-EC clones such as CTX-M-14 or -15 type ESBLs and ST131 have disseminated in community-onset infections, even in bloodstream infections, which are the most serious type of infection.
Aging ; Bacteremia/drug therapy/*epidemiology ; Biliary Tract Diseases/epidemiology/microbiology ; Cephalosporin Resistance/genetics ; Cephalosporins/therapeutic use ; Community-Acquired Infections/*epidemiology/microbiology ; Escherichia coli/isolation & purification/metabolism ; Escherichia coli Infections/drug therapy/*epidemiology ; Female ; Humans ; Male ; Microbial Sensitivity Tests ; Molecular Epidemiology ; Multilocus Sequence Typing ; Prevalence ; Retrospective Studies ; Urinary Tract Infections/epidemiology/microbiology ; beta-Lactamases/*metabolism

BACKGROUND: We evaluated the performance of the BD MAX StaphSR Assay (SR assay; BD, USA) for direct detection of Staphylococcus aureus and methicillin resistance not only in S. aureus but also in coagulase-negative Staphylococci (CNS) from positive blood cultures. METHODS: From 228 blood culture bottles, 103 S. aureus [45 methicillin-resistant S. aureus (MRSA), 55 methicillin-susceptible S. aureus (MSSA), 3 mixed infections (1 MRSA+Enterococcus faecalis, 1 MSSA+MRCNS, 1 MSSA+MSCNS)], and 125 CNS (102 MRCNS, 23 MSCNS) were identified by Vitek 2. For further analysis, we obtained the cycle threshold (Ct) values from the BD MAX system software to determine an appropriate cutoff value. For discrepancy analysis, conventional mecA/mecC PCR and oxacillin minimum inhibitory concentrations (MICs) were determined. RESULTS: Compared to Vitek 2, the SR assay identified all 103 S. aureus isolates correctly but failed to detect methicillin resistance in three MRSA isolates. All 55 MSSA isolates were correctly identified by the SR assay. In the concordant cases, the highest Ct values for nuc, mecA, and mec right-extremity junction (MREJ) were 25.6, 22, and 22.2, respectively. Therefore, we selected Ct values from 0-27 as a range of positivity, and applying this cutoff, the sensitivity/specificity of the SR assay were 100%/100% for detecting S. aureus, and 97.9%/98.1% and 99.0%/95.8% for detecting methicillin resistance in S. aureus and CNS, respectively. CONCLUSIONS: We propose a Ct cutoff value for nuc/mec assay without considering MREJ because mixed cultures of MSSA and MRCNS were very rare (0.4%) in the positive blood cultures.
Anti-Bacterial Agents/pharmacology ; Bacteremia/diagnosis/microbiology ; Coagulase/metabolism ; Humans ; Methicillin-Resistant Staphylococcus aureus/drug effects/genetics/*isolation & purification ; Microbial Sensitivity Tests ; Oxacillin/pharmacology ; Reagent Kits, Diagnostic ; Staphylococcus/drug effects/enzymology/genetics/isolation & purification ; Staphylococcus aureus/drug effects/genetics/*isolation & purification

BACKGROUNDGram-positive bacteria such as Staphylococcus aureus have been a common cause of infection among liver transplant (LT) recipients in recent decades. The understanding of local epidemiology and its evolving trends with regard to pathogenic spectra and antibiotic susceptibility is beneficial to prophylactic and empiric treatment for LT recipients. This study aimed to investigate etiology, timing, antibiotic susceptibility and risk factors for multidrug resistant (MDR) Gram-positive coccal bacteremia after LT.

METHODSA cohort analysis of prospectively recorded data was performed to investigate etiologies, timing, antibiotic susceptibility and risk factors for MDR Gram-positive coccal bacteremia in 475 LT recipients.

RESULTSIn 475 LT recipients in the first six months after LT, there were a total of 98 episodes of bacteremia caused by Gram-positive cocci in 82 (17%) patients. Seventy-five (77%) bacteremic episodes occurred in the first post-LT month. The most frequent Gram-positive cocci were methicillin-resistant coagulase-negative staphylococcus (CoNS, 46 isolates), methicillin-resistant Staphylococcus aureus (MRSA, 13) and enterococcus (34, E. faecium 30, E. faecalis 4). In all Gram-positive bacteremic isolates, 59 of 98 (60%) were MDR. Gram-positive coccal bacteremia and MDR Gram-positive coccal bacteremia predominantly occurred in patients with acute severe exacerbation of chronic hepatitis B and with fulminant/subfulminant hepatitis. Four independent risk factors for development of bacteremia caused by MDR Gram-positive coccus were: LT candidates with encephalopathy grades II - IV (P = 0.013, OR: 16.253, 95%CI: 1.822 - 144.995), pre-LT use of empirical antibiotics (P = 0.018, OR: 1.029, 95%CI: 1.002 - 1.057), post-LT urinary tract infections (P < 0.001, OR: 20.340, 95%CI: 4.135 - 100.048) and abdominal infection (P = 0.004, OR: 2.820, 95%CI: 1.122 - 10.114). The main infectious manifestations were coinfections due to gram-positive cocci and gram-negative bacilli.

CONCLUSIONSMethicillin-resistant CoNS and enterococci are predominant pathogens among LT recipients with Gram-positive coccal bacteremia. Occurrences of Gram-positive coccal bacteremia may be associated with the severity of illness in the perioperative stage.

Anti-Bacterial Agents ; pharmacology ; Bacteremia ; etiology ; microbiology ; Coagulase ; metabolism ; Drug Resistance, Multiple, Bacterial ; Enterococcus ; drug effects ; enzymology ; physiology ; Gram-Positive Bacterial Infections ; enzymology ; microbiology ; transmission ; Humans ; Liver Diseases ; microbiology ; Liver Transplantation ; adverse effects ; Risk Factors ; Staphylococcal Infections ; enzymology ; microbiology ; transmission ; Staphylococcus ; drug effects ; enzymology ; physiology