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Original Articles
Profiling Virulence and Antimicrobial Resistance Markers of Enterovirulent Escherichia Coli from Fecal Isolates of Adult Patients with Enteric Infections in West Cameroon
Wiliane J. T. Marbou, Priyanka Jain, Sriparna Samajpati, Gourab Halder, Asish K. Mukhopadhyay, Shanta Dutta, Victor Kuete
Osong Public Health Res Perspect. 2020;11(4):216-230.   Published online August 31, 2020
DOI: https://doi.org/10.24171/j.phrp.2020.11.4.11
  • 4,349 View
  • 93 Download
  • 4 Citations
AbstractAbstract PDF
Objectives

This study aimed to identify virulent and antimicrobial resistant genes in fecal E. coli in Mbouda, Cameroon.

Methods

A total of 599 fecal samples were collected from patients with enteric infections who were ≥ 20 years old. E. coli was isolated on the MacConkey agar and virulent genes were detected by multiplex/simplex PCR. Isolates in which ≥ 1 virulent gene was detected were subjected to antibiotic susceptibility testing. The resulting resistant isolates were subjected to PCR, followed by sequencing for resistant genes detection.

Results

There were 119 enterovirulent E. coli identified, amongst which 47.05% were atypical enteropathogenic E. coli (EPEC), 36.97% enterotoxigenic E. coli, 10.08% Shiga toxin producing E. coli (STEC) and 5.88% were enteroinvasive E. coli (EIEC). The occurrence of the eae gene (47.06%) was higher compared with CVD432 (33.61%), aaic (13.45%), stx2 (10.08%) and stx1 (0.84%). High resistance rates were noted for ampicillin (94.64% EPEC, 91.67% STEC, 59.09% EAEC, and 57.14% EIEC) and sulfamethoxazole-trimethoprim (100% EPEC and 83.33% STEC, 81.82% EAEC and 71.43% EIEC). sul2 (71.43%), tetB (64.71%), tetA (59.94%) and blaTEM (52.10%) were detected. A double mutation (S83L; D87N) was seen in gyrA and a single mutation (S80I) was observed in parC.

Conclusion

These findings suggested that measures should be taken to reduce the harm of E. coli to public health.

Association between Beta-lactam Antibiotic Resistance and Virulence Factors in AmpC Producing Clinical Strains of P. aeruginosa
Sanaz Dehbashi, Hamed Tahmasebi, Mohammad Reza Arabestani
Osong Public Health Res Perspect. 2018;9(6):325-333.   Published online December 31, 2018
DOI: https://doi.org/10.24171/j.phrp.2018.9.6.06
  • 20,778 View
  • 129 Download
  • 12 Citations
AbstractAbstract PDF
Objectives

The purpose of this study was to determine the presence of IMP and OXA genes in clinical strains of Pseudomonas aeruginosa (P. aeruginosa) that are carriers of the ampC gene.

Methods

In this study, 105 clinical isolates of P. aeruginosa were collected. Antibiotic resistance patterns were determined using the disk diffusion method. The strains carrying AmpC enzymes were characterized by a combination disk method. Multiplex-PCR was used to identify resistance and virulence genes, chi-square test was used to determine the relationship between variables.

Results

Among 105 isolates of P. aeruginosa, the highest antibiotic resistance was to cefotaxime and aztreonam, and the least resistance was to colictin and ceftazidime. There were 49 isolates (46.66%) that showed an AmpC phenotype. In addition, the frequencies of the resistance genes were; OXA48 gene 85.2%, OXA199, 139 3.8%, OXA23 3.8%, OXA2 66.6%, OXA10 3.8%, OXA51 85.2% and OXA58 3.8%. The IMP27 gene was detected in 9 isolates (8.57%) and the IMP3.34 was detected in 11 isolates (10.47%). Other genes detected included; lasR (17.1%), lasB (18%) and lasA (26.6%). There was a significant relationship between virulence factors and the OX and IMP genes (p ≤ 0.05).

Conclusion

The relationship between antibiotic resistance and virulence factors observed in this study could play an important role in outbreaks associated with P. aeruginosa infections.

Relationships between Virulence Factors and Antimicrobial Resistance among Escherichia coli Isolated from Urinary Tract Infections and Commensal Isolates in Tehran, Iran
Mohammad Reza Asadi Karam, Mehri Habibi, Saeid Bouzari
Osong Public Health Res Perspect. 2018;9(5):217-224.   Published online October 31, 2018
DOI: https://doi.org/10.24171/j.phrp.2018.9.5.02
  • 3,860 View
  • 103 Download
  • 16 Citations
AbstractAbstract PDF
Objectives

Uropathogenic Escherichia coli (UPEC) are the major cause of urinary tract infections (UTIs). Here, we determined whether sensitivity to antibiotics was related to the prevalence of iron scavenging genes, or to biofilm and hemolysis formation.

Methods

A total of 110 UPEC and 30 E coli isolates were collected from the urine of UTI patients and feces of healthy individuals without UTI, respectively. The presence of iron receptor genes and phenotypic properties were evaluated by polymerase chain reaction and phenotypic methods, respectively. Susceptibility to routine antibiotics was evaluated using the disc diffusion method.

Results

The prevalence of iron scavenging genes ranged from 21.8% (ireA) to 84.5% (chuA) in the UPEC. Resistance to ceftazidime and cefotaxime was significantly correlated with the presence of fyuA and iutA iron genes. Biofilm production was significantly associated with the prevalence of fyuA and hma iron genes. A higher degree of antibiotic resistance was exhibited by isolates that produced biofilms than by their non-biofilm producing counterparts.

Conclusion

Our study clearly indicates that biofilm production is associated with antibiotic resistance, and that iron receptors and hemolysin production also contribute to reduced antibiotic sensitivity. These results further our understanding of the role that these virulence factors play during UPEC pathogenesis, which in turn may be valuable for the development of novel treatment strategies against UTIs.

Profiling of Virulence-associated Factors in Shigella Species Isolated from Acute Pediatric Diarrheal Samples in Tehran, Iran
Sajad Yaghoubi, Reza Ranjbar, Mohammad Mehdi Soltan Dallal, Somayeh Yasliani Fard, Mohammad Hasan Shirazi, Mahmood Mahmoudi
Osong Public Health Res Perspect. 2017;8(3):220-226.   Published online June 30, 2017
DOI: https://doi.org/10.24171/j.phrp.2017.8.3.09
  • 2,714 View
  • 31 Download
  • 14 Citations
AbstractAbstract PDF
Objectives

The genus Shigella comprises the most infectious and diarrheagenic bacteria causing severe diseases, mostly in children under five years of age. This study aimed to detect nine virulence genes (ipaBCD, VirA, sen, set1A, set1B, ial, ipaH, stx, and sat) in Shigella species (spp.) using multiplex polymerase chain reaction (MPCR) and to determine the relation of Shigella spp. from pediatric diarrheal samples with hospitalization and bloody diarrhea in Tehran, Iran.

Methods

Shigella spp. were isolated and identified using standard microbiological and serological methods. The virulence genes were detected using MPCR.

Results

Seventy-five Shigella spp. (40 S. sonnei, 33 S. flexneri, 1 S. dysenteriae, and 1 S. boydii) were isolated in this study. The prevalence of ial, sen, sat, set1A, and set1B was 74.7%, 45.4%, 28%, 24%, and 24%, respectively. All S. flexneri isolates, while no S. sonnei, S. dysenteriae, or S. boydii isolates, contained sat, set1A, and set1B. All isolates were positive for ipaH, ipaBCD, and virA, while one (1.4%) of the isolates contained stx. The highest prevalence of virulence determinants was found in S. flexneri serotype IIa. Nineteen (57.6%) of 33 S. flexneri isolates were positive for ipaBCD, ipaH, virA, ial, and sat. The sen determinants were found to be statistically significantly associated with hospitalization and bloody diarrhea (p = 0.001).

Conclusion

This study revealed a high prevalence of enterotoxin genes in S. flexneri, especially in serotype 2a, and has presented relations between a few clinical features of shigellosis and numerous virulence determinants of clinical isolates of Shigella spp.

Phenotypic Assays to Determine Virulence Factors of Uropathogenic Escherichia coli (UPEC) Isolates and their Correlation with Antibiotic Resistance Pattern
Mohsen Tabasi, Mohammad Reza Asadi Karam, Mehri Habibi, Mir Saeed Yekaninejad, Saeid Bouzari
Osong Public Health Res Perspect. 2015;6(4):261-268.   Published online August 31, 2015
DOI: https://doi.org/10.1016/j.phrp.2015.08.002
  • 2,072 View
  • 18 Download
  • 39 Citations
AbstractAbstract PDF
Objectives
Urinary tract infection caused by uropathogenic Escherichia coli (UPEC) strains is one of the most important infections in the world. UPEC encode widespread virulence factors closely related with pathogenesis of the bacteria. The purpose of this study was to evaluate the presence of different phenotypic virulence markers in UPEC isolates and determine their correlation with antibiotic resistance pattern.
Methods
UPEC isolates from patients with different clinical symptoms of UTI were collected and screened for biofilm and hemolysin production, mannose resistant, and mannose sensitive hemagglutination (MRHA and MSHA, respectively). In addition, antimicrobial resistance pattern and ESBL-producing isolates were recorded.
Results
Of the 156 UPEC isolates, biofilm and hemolysin formation was seen in 133 (85.3%) and 53 (34%) isolates, respectively. Moreover, 98 (62.8%) and 58 (37.2%) isolates showed the presence of Types 1 fimbriae (MSHA) and P fimbriae (MRHA), respectively. Our results also showed a relationship between biofilm formation in UPEC isolated from acute cystitis patients and recurrent UTI cases. Occurrence of UTI was dramatically correlated with the patients' profiles. We observed that the difference in antimicrobial susceptibilities of the biofilm and nonbiofilm former isolates was statistically significant. The UPEC isolates showed the highest resistance to ampicillin, tetracycline, amoxicillin, and cotrimoxazole. Moreover, 26.9% of isolates were ESBL producers.
Conclusion
This study indicated that there is a relationship between the phenotypic virulence traits of the UPEC isolates, patients' profiles, and antibiotic resistance. Detection of the phenotypic virulence factors could help to improve understanding of pathogenesis of UPEC isolates and better medical intervention.
Multilocus Sequence Analysis of Housekeeping Genes and Antigenic Determinant Genes in Bordetella pertussis Strains Isolated in Korea
Sang-Oun Jung, Yu Mi Moon, So-Hyeon Kim, Hwa Young Sung, Seung-Jik Kwon, Yeon Ho Kang, Jae Yon Yu
Osong Public Health Res Perspect. 2011;2(2):115-126.   Published online June 30, 2011
DOI: https://doi.org/10.1016/j.phrp.2011.08.003
  • 1,752 View
  • 13 Download
  • 3 Citations
AbstractAbstract PDF
Objectives
To confirm genotype diversities of clinical isolates of Bordetella pertussis and to evaluate the risk of pertussis outbreak in Korea.
Methods
Seven housekeeping genes and 10 antigenic determinant genes from clinical B. pertussis isolates were analyzed by Multilocus sequence typing (MLST).
Results
More variant pattern was observed in antigenic determinant genes. Especially, PtxS1 gene was the most variant gene; five genotypes were observed from eight global genotypes. In the bacterial type, the number of observed sequence types in the isolates was seven and the most frequent form was type 1 (79.6%). This major sequence type also showed a time-dependent transition pattern. Older isolates (1968 and 1975) showed type 1 and 6 in housekeeping genes and antigenic determinant genes, respectively. However, these were changed to type 2 and 1 in isolates 1999–2008. This transition was mainly attributed to genotype change of PtxS1 and Fim3 gene; the tendency of genotype change was to avoid vaccine-derived genotype. In addition, there was second transition in 2009. In this period, only the sequence type of antigenic determinant genes was changed to type 2. Based Upon Related Sequence Types (BURST) analysis confirmed that there were two clonal complexes (ACCI and ACCII) in the Korean isolates. Moreover, the recently increased sequence type was revealed as AST2 derived from AST 3 in ACCI.
Conclusions
Genotype changes in Korean distributing strains are still progressing and there was a specific driving force in antigenic determinant genes. Therefore continuous surveillance of genotype change of the distributing strains should be performed to confirm interrelationship of genotype change with vaccine immunity.
Distribution of Virulence Genes and Their Association of Serotypes in Pathogenic Escherichia coli Isolates From Diarrheal Patients in Korea
Seung-Hak Cho, Kyung-Hwan Oh, Seong-Han Kim, Hee-Bok Oh, Mi-Sun Park
Osong Public Health Res Perspect. 2010;1(1):29-35.   Published online December 31, 2010
DOI: https://doi.org/10.1016/j.phrp.2010.12.008
  • 1,889 View
  • 15 Download
  • 5 Citations
AbstractAbstract PDF
Objectives
To characterise the genetic and serological diversity of pathogenic Escherichia coli, we tested 111 E coli strains isolated from diarrhoeal patients in Korea between 2003 and 2006.
Methods
The isolates were tested through polymerase chain reaction (PCR) and slide agglutination method for the detection of virulence genes and serotypes, respectively. To compare the expression of Shiga toxin (stx)-1 and stx2 genes, real-time quantitative reverse-transcriptase PCR and rapid exprssion assay, reversed-passive latex agglutination, were performed.
Results
Forty-nine Shiga toxin-producing E coli (STEC) strains and 62 non-STEC strains, including 20 enteropathogenic E coli, 20 enterotoxigenic E coli, 20 enteroaggregative E coli, and 2 enteroinvasive E coli were randomly chosen from the strains isolated from diarrhoeal patients in Korea between 2003 and 2006. PCR analysis indicated that locus of enterocyte effacement pathogenicity island, that is, eaeA, espADB, and tir genes were present in STEC, enteropathogenic E coli, and enteroinvasive E coli. Quorum sensing-related gene luxS was detected in most of pathogenic E coli strains. Major serotypes of the STEC strains were O157 (26%) and O26 (20%), whereas the non-STEC strains possessed various serotypes. Especially, all the strains with serotype O157 carried stx2 and the tested virulence factors. Of the STEC strains, the data of real-time quantitative reverse-transcriptase PCR and reversed-passive latex agglutination tests showed that messenger RNA- and protein expression of stx2 gene were higher than those of stx1 gene.
Conclusion
Our results provide the epidemiological information regarding the trend of STEC and non-STEC infections in the general population and show the fundamental data in association of serotypes with virulence genes in diarrhoeagenic E coli strains from Korea.

PHRP : Osong Public Health and Research Perspectives