Cholera is a secretory diarrhoeal disease caused by infection with Vibrio cholerae, primarily the V. cholerae O1 El Tor biotype. There are approximately 2.9 million cases in 69 endemic countries annually, resulting in 95 000 deaths. Cholera is associated with poor infrastructure and lack of access to sanitation and clean drinking water. The current cholera epidemic in Yemen, linked to spread of V. cholerae O1 (Ogawa serotype), is associated with the ongoing war. This has devastated infrastructure and health services. The World Health Organization had estimated that 172 286 suspected cases arose between 27th April and 19th June 2017, including 1170 deaths. While there are three oral cholera vaccines prequalified by the World Health Organization, there are issues surrounding vaccination campaigns in conflict situations, exacerbated by external factors such as a global vaccine shortage. Major movements of people complicates surveillance and administration of double doses of vaccines. Cholera therapy mainly depends on rehydration, with use of antibiotics in more severe infections. Concerns have arisen about the rise of antibiotic resistance in cholera, due to mobile genetic elements. In this review, we give an overview of cholera epidemiology, virulence, antibiotic resistance, therapy and vaccines, in the light of the ongoing epidemic in Yemen.
Anti-Bacterial Agents ; therapeutic use ; Cholera ; drug therapy ; prevention & control ; Cholera Vaccines ; therapeutic use ; DNA, Bacterial ; genetics ; Disease Outbreaks ; Drug Resistance, Multiple, Bacterial ; Humans ; Microbial Sensitivity Tests ; Polymerase Chain Reaction ; Vibrio cholerae ; drug effects ; isolation & purification ; Virulence Factors ; genetics ; Yemen

To determine the lysis spectrum of Yersinia enterocolitica bacteriophage phiYe-F10 and to analyze the relationship between the lysis ability of phiYe-F10 and the virulence gene of Yersinia enterocolitica. To observe the lysis ability of the phage phiYe-F10 to the different Yersinia strains with the double-layer technique. The strains used in this study including 213 of Yersinia enterocolitica and 36 of Yersinia pseudotuberculosis and 1 of Yersinia pestis. The virulence genes of these Yersinia enterocolitica (attachment invasion locus (ail) and enterotoxin (ystA, ystB) and yersinia adhesin A (yadA), virulence factor (virF), specific gene for lipopolysaccharide O-side chain of serotype O : 3 (rfbc) were all detected. Among the 213 Yersinia enterocolitica, 84 strains were O : 3 serotype (78 strains with rfbc gene), 10 were serotype O : 5, 13 were serotype O : 8, 34 were serotype O : 9 and 72 were other serotypes. Of these, 77 were typical pathogenic Yersinia enterocolitica harboring with virulence plasmid (ail+, ystA+, ystB-, yadA+, virF+), and 15 were pathogenic bacterial strains deficiency virulence plasmid (ail+, ystA+, ystB-, yadA-, virF-) and the rest 121 were non pathogenic genotype strains. PhiYe-F10 lysed the 71 serotype O : 3 Yersinia enterocolitica strains which were all carried with rfbc+, including 52 pathogenic Yersinia enterocolitica, 19 nonpathogenic Y. enterocolitica. The phiYe-F10 can not lysed serotype O : 5, O : 9 and other serotype Y. enterocolitica, the lysis rate of serotype O : 3 was as high as 84.5%. The phiYe-F10 can not lysed Yersinia pseudotuberculosis and Yersinia pestis. Yersinia phage phiYe-F10 is highly specific for serotype O : 3 Yersinia enterocolitic at 25 degrees C, which showed a typical narrow lysis spectrum. Phage phiYe-F10 can lysed much more pathogenic Y. enterocolitica than nonpathogenic Y. enterocolitica.
Bacterial Proteins ; genetics ; metabolism ; Bacteriophages ; genetics ; isolation & purification ; physiology ; Host Specificity ; Virulence Factors ; genetics ; metabolism ; Yersinia enterocolitica ; genetics ; metabolism ; virology

OBJECTIVETo establish Surface-enhanced Raman Spectroscopy (SERS) can be used as a rapid and reliable method to distinguish virulent strain and mild strain of L. pneumophila.

METHODSMortality data were collected from company departments through administrative documents, death certificates, etc. Trend analyses of cancer mortality were performed on the basis of 925 cancer deaths between 2001 and 2010.

RESULTSOur results indicated that the peaks of high virulence strains reached ⋝4000. This criterion was verified by subsequent cell experiments. In addition, we also conducted SERS rapid identification on the virulence of several collected clinical strains and obtained accurate results.

CONCLUSIONThe present study indicates that the established SERS protocol can be used as a rapid and reliable method to distinguish virulent and mildly virulent strains of L. pneumophila, which can be further used in clinical samples.

Cell Line ; Citric Acid ; chemistry ; Gold ; chemistry ; Humans ; Legionella ; isolation & purification ; pathogenicity ; Nanoparticles ; chemistry ; Spectrum Analysis, Raman ; methods ; Time Factors ; Tiopronin ; chemistry ; Virulence

Anti-Bacterial Agents ; Child ; China ; epidemiology ; Drug Resistance, Bacterial ; genetics ; Erythromycin ; Humans ; Molecular Epidemiology ; Streptococcus pyogenes ; genetics ; isolation & purification ; pathogenicity ; Virulence Factors ; genetics

OBJECTIVETo investigate drug-resistance and carriage of virulence factors of Pseudomonas aeruginosa (Pa) isolated from children.

METHODThirty-eight strains of Pa were collected and isolated in pediatric clinic during 2006-2009, and tests were undertaken to identify bacteria and susceptibility test was performed using VITEK-2 COMPACT GNI and AST-GN13 cards. The virulence factors were confirmed by using polymerase chain reaction (PCR) and sequencing.

RESULTAll the 38 strains of Pa were resistant to ampicillin, ampicillin/sulbactam, cefazolin, nitrofurantoin, trimethoprim/sulfamethoxazole, resistance rates were 100%. Except for ceftriaxone (60.53%), the resistance rates to other antibiotics were all below 16%. PCR test showed that all the 38 strains of Pa carried exotoxin A(toxA) and nitric oxide reductase A (norA), however, detective ratio of the other virulence factors, exoenzyme Y (exoY) was 84.21% (32/38), exoenzyme S (exoS) 57.89% (22/38), pyocyanin (pyp) 42.11% (16/38), exoenzyme U (exoU) 34.21% (13/38), and 38 strains of Pa did not carry exoenzyme T (exoT) and elastase B (lasB) without exception. By analyzing tests, we discovered that 3 pan-drug resistant strains of Pa were all combination of exo U+/pyp+, there were 4 strains of Pa which were moderately-resistant to imipenem, including exoU+/pyp+/exoY+ (2 isolates), exo U+/pyp+ (1 isolate), and exoY+/exoS+ (1 isolates). It indicated that the drug-resistance rate of exoU+/pyp+ is much higher, compared with exoS+ and exoY+. Molecular epidemiological detection revealed that 2 of 3 extensive-resistance strains of Pa were the same clone, but another one had 96.3% of homology with them.

CONCLUSIONThe above mentioned 34.21% of Pa isolated from children carried virulence factors toxA, norA, exoS, exoY, pyp and exoU. The strains with exoU/pyp had rather high resistance. The strains with pyp had strong toxicity, they easily cause generalized infection, the patients with them had very high mortality.

ADP Ribose Transferases ; genetics ; Bacterial Proteins ; genetics ; Bacterial Toxins ; genetics ; Carrier State ; epidemiology ; microbiology ; Child ; Drug Resistance, Multiple, Bacterial ; genetics ; Exotoxins ; Genes, Bacterial ; Humans ; Microbial Sensitivity Tests ; Polymerase Chain Reaction ; Pseudomonas Infections ; epidemiology ; genetics ; microbiology ; Pseudomonas aeruginosa ; genetics ; isolation & purification ; pathogenicity ; Virulence Factors ; genetics

Helicobacter pylori has been strongly associated with gastritis, gastric and duodenal ulcers, and it is a risk factor for gastric cancer. Two major virulence factors of H. pylori have been described: the cytotoxin-associated gene product (cagA) and the vacuolating toxin (vacA). Since considerable geographic diversity in the prevalence of H. pylori virulence factors has been reported, the aim of this work was to determine if there is a significant correlation between different H. pylori virulence genes (cagA and vacA) in 68 patients, from Saudi Arabia, and gastric clinical outcomes. H. pylor was recognized in cultures of gastric biopsies. vacA and cagA genes were detected by polymerase chain reaction (PCR). The cagA gene was obtained with 42 isolates (61.8%). The vacA s- and m- region genotypes were determined in all strains studied. Three genotypes were found: s1/m1 (28%), s1/m2 (40%) and s2/m2 (26%). The s2/m1 genotype was not found in this study. The relation of the presence of cagA and the development of cases to gastritis and ulcer was statistically significant (P < 0.05). The study showed a significant correlation between the vacA s1/m2 genotype and gastritis cases, and a significant correlation between vacA s1/m1 genotype and peptic ulcer cases. The results of this study might be used for the identification of high-risk patients who are infected by vacA s1/m1 genotype of H. pylori strains. In conclusion, H. pylori strains of vacA type s1 and the combination of s1/m1 were associated with peptic ulceration and the presence of cagA gene.
Adolescent ; Adult ; Aged ; Aged, 80 and over ; Antigens, Bacterial/*genetics ; Bacterial Proteins/*genetics ; DNA, Bacterial/genetics ; Female ; Gastritis/genetics/microbiology/pathology ; Genotype ; Helicobacter Infections/*epidemiology/*microbiology/pathology ; Helicobacter pylori/*genetics/isolation & purification ; Humans ; Male ; Middle Aged ; Peptic Ulcer/genetics/microbiology/pathology ; Polymerase Chain Reaction ; Saudi Arabia ; Virulence Factors/genetics ; Young Adult

This study was conducted to determine the prevalence and characteristics of pathogenic Escherichia (E.) coli strains from diarrheic calves in Vietnam. A total of 345 E. coli isolates obtained from 322 diarrheic calves were subjected to PCR and multiplex PCR for detection of the f5, f41, f17, eae, sta, lt, stx1, and stx2 genes. Of the 345 isolates, 108 (31.3%) carried at least one fimbrial gene. Of these 108 isolates, 50 carried genes for Shiga toxin and one possessed genes for both enterotoxin and Shiga toxin. The eae gene was found in 34 isolates (9.8%), 23 of which also carried stx genes. The Shiga toxin genes were detected in 177 isolates (51.3%) and the number of strains that carried stx1, stx2 and stx1/stx2 were 46, 73 and 58, respectively. Among 177 Shiga toxin-producing E. coli isolates, 89 carried the ehxA gene and 87 possessed the saa gene. Further characterization of the stx subtypes showed that among 104 stx1-positive isolates, 58 were the stx1c variant and 46 were the stx1 variant. Of the 131 stx2-positive strains, 48 were stx2, 48 were stx2c, 11 were stx2d, 17 were stx2g, and seven were stx2c/stx2g subtypes. The serogroups most prevalent among the 345 isolates were O15, O20, O103 and O157.
Animals ; Cattle ; Cattle Diseases/epidemiology/*microbiology ; DNA, Bacterial/chemistry/genetics ; Diarrhea/epidemiology/microbiology/*veterinary ; Escherichia coli/genetics/*isolation & purification/pathogenicity ; Escherichia coli Infections/epidemiology/microbiology/*veterinary ; Feces/microbiology ; Fimbriae, Bacterial/genetics ; Polymerase Chain Reaction/veterinary ; Polymorphism, Restriction Fragment Length ; Vietnam/epidemiology ; Virulence Factors/*genetics

BACKGROUND: Various virulence factors and superantigens are encoded by mobile genetic elements. The relationship between clonal background and virulence factors differs in different geographic regions. We compared the distribution and relationship of spa types and virulence genes among methicillin-resistant Staphylococcus aureus (MRSA) strains isolated from a tertiary hospital in 2000-01 and 2007-08. METHODS: In 2000-01 and 2007-08, 94 MRSA strains were collected from 3 intensive care units at a Korean tertiary hospital. We performed spa typing and multiplex PCR for 19 superantigen genes. RESULTS: Relatively frequent spa types were t037 (40.5%), t002, t601, and t2138 in 2000-01, and t2460 (43.9%), t002, t037, t601, t324, and t2139 in 2007-08. We identified 4 novel spa types, 2 of which were designated as t5076 and t5079. Superantigen profiles were closely linked to spa types. For example, sea, sek, and seq superantigen genes were mainly detected in t037 strains. CONCLUSIONS: Major spa types differed depending on study periods, and the distribution of superantigen genes correlated with spa type.
Bacterial Typing Techniques ; DNA, Bacterial/chemistry ; Genotype ; Humans ; Intensive Care Units/statistics & numerical data ; Methicillin-Resistant Staphylococcus aureus/genetics/*isolation & purification/pathogenicity ; Microbial Sensitivity Tests ; Polymerase Chain Reaction ; Staphylococcal Infections/microbiology ; Superantigens/genetics ; Virulence/genetics ; Virulence Factors/*genetics

OBJECTIVETo study the virulent gene prevalence of foodborne Listeria monocytogenes (LM) isolated from China.

METHODS78 LM isolates derived from raw meat, cooked food, aquatic products and vegetables of 13 provinces and cities.LM isolates were investigated for prevalence of virulence genes (LIPI-1 (prfA, plcA, hly, mpl, actA, plcB); LIPI-2 (inlA, inlB), and iap) by PCR method.

RESULTS87.2% (68/78) of the isolates were prfA positive, 98.7% (77/78) of the isolates were plcA, actA and plcB positive, 97.4% (76/78) of the isolates were hly positive, 87.2% (68/78) of the isolates were mpl positive, 92.3% (72/78) of the isolates were inlA positive, 100% (78/78) of the isolates were inlB positive, 98.7% (77/78) of the isolates were iap positive. Among 21 virulent gene negative isolates, there was 7 isolates lack of two or more virulence genes. The rate of virulence genes deletion isolates from cooked meat was 31.3% (10/32), the rate of virulence genes deletion isolates from raw meat was 16.1% (5/31), the rate of virulence genes deletion isolates from vegetables was 36.4% (4/11) and rate of virulence genes deletion isolates from seafood was 50% (2/4). No significant difference was found (χ(2) = 3.721, P > 0.05). The virulence gene array-1 strains were dominant among these isolates.

CONCLUSIONAmong 78 LM isolates, prevalent of virulent genes were different except inlB, virulence genes of LIP-1 were deleted prevalently among isolates, virulence gene deletion patterns were diverse.

China ; epidemiology ; Food Contamination ; analysis ; Food Microbiology ; Foodborne Diseases ; epidemiology ; microbiology ; Listeria monocytogenes ; genetics ; isolation & purification ; pathogenicity ; Listeriosis ; epidemiology ; microbiology ; Virulence Factors ; genetics

M2 protein of type A influenza virus is a good candidate for universal influenza vaccine, exotoxin A of Pseudomonas aeruginosa may facilitate the immunogenicity of M2 protein. We constructed and expressed a prokaryotic expression plasmid containing a chimeric gene of M2 extracellular coding region and a partial PEA gene, and observed the immunoprotection in BALB/c mice vaccinated with the fusion protein. The fusion protein (ntPE-M2e) was generated by inserting the coding sequence of the M2e in place of Ib loop in PEA. This fusion protein was used to immunize BALB/c mice by subcutaneously injection with incomplete Freund's adjuvant and boost at weeks 3 and 7. The immunized mice were challenged with influenza virus strain A/PR/34/8. The fusion protein (ntPE-M2e) immunization protected mice against lethal viral challenge. ELISA and ELISPOT results demonstrated that the fusion protein could induce a strong systemic immune response against synthetic M2e peptide, and virus replication in the lungs of mice was inhibited in comparison with the control. This study provides foundation for developing broad-spectrum vaccines against type A influenza viruses.
ADP Ribose Transferases ; genetics ; Animals ; Bacterial Toxins ; genetics ; Enzyme-Linked Immunosorbent Assay ; Escherichia coli ; genetics ; Exotoxins ; genetics ; Female ; Gene Expression ; Immunization ; Influenza A virus ; immunology ; physiology ; Lung ; immunology ; virology ; Mice ; Mice, Inbred BALB C ; Recombinant Fusion Proteins ; biosynthesis ; genetics ; immunology ; isolation & purification ; Viral Matrix Proteins ; biosynthesis ; genetics ; immunology ; isolation & purification ; Virulence Factors ; genetics