Bacterial Infections ; Humans ; Respiratory Hypersensitivity ; microbiology

Child ; Community-Acquired Infections ; microbiology ; Humans ; Pneumonia, Bacterial ; microbiology

OBJECTIVE: To observe the micromorphological characteristic of bacterial biofilm on mucosa of chronic rhinosinusitis (CRS). METHOD: Mucosa samples of middle turbinate were obtained from 4 patients of CRS during ESS. The size of each sample was about 4 mm x 4 mm. The samples were fixed in 4% paraformaldehyde for 24 hours, then fixed in 1% osmium tetroxide for 2 hours, graded dehydration with ethanol, dried with carbon dioxide and sputter coated with gold. The ultrastructure of these samples was observed by scanning electron microscope. RESULT: Bacterial biofilms were found on samples in all 4 patients. The biofilms were mainly formed on the surface of cilia. The bacterial flagella and cilia were intertwined. The biofilms could be found in a lot kinds of bacterial infections or mixed infections which were caused by multiple bacteria and fungi. CONCLUSION Bacterial biofilm could be formed on ciliated epithelia.
Bacterial Infections ; microbiology ; Biofilms ; Cilia ; microbiology ; ultrastructure ; Epithelium ; microbiology ; ultrastructure ; Humans ; Microscopy, Electron, Scanning ; Sinusitis ; microbiology

OBJECTIVETo observe the biofilm (BF) formation of Staphylococcus aureus (SA), Acinetobacter baumannii (AB) and Pseudomonas aeruginosa (PA) on the surface of deep vein catheters in burn patients after infection.

METHODSThe bacteria from deep vein catheters in 20 patients hospitalized from November 2008 to August 2009 were isolated, and were compared with their respective standard stains. Catheters tips were examined with scanning electron microscope (SEM). The semi-quantitative adhesion assay of bacterial BF was performed with modified microtiter-plate test, and the thickness of BF was scanned and measured by confocal laser scanning microscopy (CLSM) after double fluorescence staining, after being cultured in vitro for 12, 24, 48, 72 hours and 5 days, respectively. Data were processed with grouped t test.

RESULTSSix strains of SA, 8 strains of AB, and 6 strains of PA, all drug resistant, were isolated from the deep vein catheters. SEM showed that the BF structures on the inner surfaces of catheters were in diverse in their shape and degree, characterized by adherence and flake formation, and embedded in polysaccharide matrix. BF gathered in clusters, forming three-dimensional structure, in which small amount of red blood cells were found. A small number of bacteria were incompletely embedded, with some bacteria adhered to them. The absorbance values for SA after 24, 48 and 72 hours of culture (PCH) were above the cut-off value, the same for AB at PCH 12, 24, 48 and 72, and PA after PCH 48. Except for PA standard strain, CLSM showed scattered green fluorescence, mainly close to the bottom of plate, while the red fluorescence was observed in full scope at PCH 24 for each strain. At PCH 48 green fluorescence increased obviously and extended upward from the bottom, overlapping partly with red fluorescence, forming yellow fluorescence, and among the bacteria it was most obvious in AB culture, with SA the next. Compared with those of the standard stains, the intensity and quantity of fluorescence from the clinical strains were stronger; at PCH 72 the green fluorescence increased obviously especially for PA and its standard strain, while the yellow fluorescence was full of the scope for other strains. On in vitro culture day 5, the green fluorescence was dispersed and was obvious on the bottom of the plate. BF mature time for AB and SA was PCH 48, and for PA was PCH 72. The BF thickness of AB was (18.2 +/- 3.6) microm at PCH 72, which was thicker than that [(9.4 +/- 2.6) microm] of its standard strain (t = 5.42, P < 0.05), and was also the thickest among the three clinically found strains.

CONCLUSIONSSA, AB and PA, which are commonly found bacteria in burn patients, can form BF in deep vein catheters. Their ability to form BF seems to be stronger than other usually pathogenic strains, especially AB, which is the important pathogen leading to catheter related infection.

Acinetobacter Infections ; microbiology ; Acinetobacter baumannii ; growth & development ; Bacterial Adhesion ; Biofilms ; Burns ; microbiology ; Catheters ; microbiology ; Humans ; Pseudomonas Infections ; microbiology ; Pseudomonas aeruginosa ; growth & development ; Staphylococcal Infections ; microbiology ; Veins ; microbiology

Humans ; Endophthalmitis/microbiology* ; Eye Infections, Bacterial/microbiology* ; Anti-Bacterial Agents/therapeutic use* ; Retrospective Studies

Ascites ; Bacterial Infections ; Humans ; Liver Cirrhosis ; Peritonitis ; microbiology ; Risk Factors

Accumulating evidence suggests that intestinal bacteria play an important role in the pathogenesis of colorectal cancer (CRC). Due to the complexity of the intestinal microbiome, identification of the specific causative microbial agents in CRC remains challenging, and the search for the causative microbial agents is intense. However, whether bacteria or their products can induce inflammation that results in tumorigenesis or directly causes CRC in humans is still not clear. This review will mainly focus on the progress of bacterial infection and CRC, and introduce the microbial contribution to the hallmarks of cancer. This article uses Salmonella and its chronic infection as an example to investigate a single pathogen and its role in the development of CRC, based on laboratory and epidemiological evidence. The bacterial infection leads to an altered intestinal microbiome. The review also discusses the dysfunction of the microbiome and the mechanism of host-microbial interactions, for example, bacterial virulence factors, key signaling pathways in the host, and microbial post-translational modifications in the tumorigenesis. Colonic carcinogenesis involves a progressive accumulation of mutations in a genetically susceptible host leading to cellular autonomy. Moving forward, more human data are needed to confirm the direct roles of bacterial infection in CRC development. Insights into the inhibiting infection will help to prevent cancer and develop strategies to restore the balance between host and microorganisms.
Bacterial Infections/complications* ; Carcinogenesis ; Colorectal Neoplasms/microbiology* ; Gastrointestinal Microbiome ; Humans

Formation of biofilm is a survival strategy for bacteria and fungi to adapt to their living environment, especially in the hostile environment. Under the protection of biofilm, microbial cells in biofilm become tolerant and resistant to antibiotics and the immune responses, which increases the difficulties for the clinical treatment of biofilm infections. Clinical and laboratory investigations demonstrated a perspicuous correlation between biofilm infection and medical foreign bodies or indwelling devices. Clinical observations and experimental studies indicated clearly that antibiotic treatment alone is in most cases insufficient to eradicate biofilm infections. Therefore, to effectively treat biofilm infections with currently available antibiotics and evaluate the outcomes become important and urgent for clinicians. The review summarizes the latest progress in treatment of clinical biofilm infections and scientific investigations, discusses the diagnosis and treatment of different biofilm infections and introduces the promising laboratory progress, which may contribute to prevention or cure of biofilm infections. We conclude that, an efficient treatment of biofilm infections needs a well-established multidisciplinary collaboration, which includes removal of the infected foreign bodies, selection of biofilm-active, sensitive and well-penetrating antibiotics, systemic or topical antibiotic administration in high dosage and combinations, and administration of anti-quorum sensing or biofilm dispersal agents.
Anti-Bacterial Agents ; therapeutic use ; Bacterial Infections ; drug therapy ; microbiology ; Biofilms ; Drug Resistance, Bacterial ; Humans

Anti-Bacterial Agents/therapeutic use* ; Bacterial Infections/microbiology* ; Drug Resistance, Bacterial ; Humans ; Microbial Sensitivity Tests

OBJECTIVETo observe expressions of pgaABC gene clusters and changes in biofilm (BF) phenotype in Acinetobacter baumannii (AB) isolated from burn patients.

METHODSFrom January 2009 to October 2010, 24 strains of AB isolated from burn patients hospitalized in our burn wards were collected for the study, while the standard strain ATCC 19606 was used as control. Expressions of pgaABC gene clusters were detected by real time fluorescence quantitative RT-PCR. All strains were cultured for 16 hours in vitro, BF with semi-quantitative detection was respectively evaluated by modified microtiter-plate test under stable condition and tube test under shaking condition for expression of absorbance value. All strains were cultured for 48 hours in vitro, then stained with fluorescent agent and collected for measurement of BF thickness with confocal laser scanning microscopy (CLSM). Data were processed with t test.

RESULTS(1) The expression of pgaB gene (27.91 ± 7.93) in clinical AB strains was much higher than that of standard strain ATCC 19606 (1.00, t = 5.77, P < 0.05). There was no statistical difference in expression of pgaA and pagC genes between standard strain ATCC 19606 (1.00) and clinical AB strains (1.01 ± 0.28, 1.15 ± 0.38, with t value respectively 0.04, 0.64, P values all above 0.05). (2) After being cultured for 16 hours, BF of clinical AB strains cultured under shaking condition formed distinct "purple circle", and its absorbance value (1.25 ± 0.31) was higher than that in standard strain ATCC 19606 (0.76 ± 0.03, t = 2.67, P < 0.05). There was no obvious difference in absorbance value between clinical AB strains and standard strain ATCC19606 cultured under stable condition. (3) After being culture for 48 hours, green fluorescence intensity and distribution in extracellular matrix of clinical AB strains were stronger as compared with those of standard strain ATCC 19606, and BF thickness in clinical AB strains [(27.3 ± 9.4)µm] was thicker than that in standard strain ATCC 19606 [(15.6 ± 1.7) µm, t = 2.09, P < 0.05].

CONCLUSIONSThe high expression of pgaB gene in AB strains isolated from burn patients can induce production of extracellular matrix, which may be related to increase in the ability and thickness of BF formation.

Acinetobacter Infections ; microbiology ; Acinetobacter baumannii ; genetics ; isolation & purification ; Biofilms ; Burns ; microbiology ; Genes, Bacterial ; Humans ; Multigene Family