Effect of 16S rRNA gene mutations on tetracycline resistance in Helicobacter pylori

ABSTRACT The triple-base-pair 16S rDNA mutation AGA926-928→TTC mediates high-level tetracycline resistance in Helicobacter pylori. In contrast, single- and double-base-pair mutations mediated only low-level tetracycline resistance and decreased growth rates in the presence of tetracycline, explaining the preference for the TTC mutation in tetracycline-resistant H. pylori isolates.

Download Full-text

Mutations in the 16S rRNA Genes of Helicobacter pylori Mediate Resistance to Tetracycline

Journal of Bacteriology ◽

10.1128/jb.184.8.2131-2140.2002 ◽

2002 ◽

Vol 184 (8) ◽

pp. 2131-2140 ◽

Cited By ~ 92

Author(s):

Catharine A. Trieber ◽

Diane E. Taylor

Keyword(s):

Helicobacter Pylori ◽

16S Rrna ◽

16S Rrna Gene ◽

Tetracycline Resistance ◽

Clinical Isolates ◽

16S Rrna Genes ◽

Rrna Genes ◽

Rrna Gene ◽

Nucleotide Substitutions ◽

The 16S Rrna Gene

ABSTRACT Low-cost and rescue treatments for Helicobacter pylori infections involve combinations of several drugs including tetracycline. Resistance to tetracycline has recently emerged in H. pylori. The 16S rRNA gene sequences of two tetracycline-resistant clinical isolates (MIC = 64 μg/ml) were determined and compared to the consensus H. pylori 16S rRNA sequence. One isolate had four nucleotide substitutions, and the other had four substitutions and two deletions. Natural transformation with the 16S rRNA genes from the resistant organisms conferred tetracycline resistance on susceptible strains. 16S rRNA genes containing the individual mutations were constructed and tested for the ability to confer resistance. Only the 16S rRNA gene containing the triple mutation, AGA965-967TTC, was able to confer tetracycline resistance on H. pylori 26695. The MICs of tetracycline for the transformed strains were equivalent to those for the original clinical isolates. The two original isolates were also metronidazole resistant, but this trait was not linked to the tetracycline resistance phenotype. Serial passage of several H. pylori strains on increasing concentrations of tetracycline yielded mutants with only a very modest increase in tetracycline resistance to a MIC of 4 to 8 μg/ml. These mutants all had a deletion of G942 in the 16S rRNA genes. The mutations in the 16S rRNA are clearly responsible for tetracycline resistance in H. pylori.

Download Full-text

Association between 16S rRNA gene mutations and susceptibility to amikacin in Mycobacterium avium Complex and Mycobacterium abscessus clinical isolates

Scientific Reports ◽

10.1038/s41598-021-85721-5 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Su-Young Kim ◽

Dae Hun Kim ◽

Seong Mi Moon ◽

Ju Yeun Song ◽

Hee Jae Huh ◽

...

Keyword(s):

16S Rrna ◽

16S Rrna Gene ◽

Mycobacterium Avium ◽

Inhibitory Concentration ◽

Gene Mutations ◽

Mycobacterium Abscessus ◽

Clinical Isolates ◽

Rrna Gene ◽

High Level ◽

Culture Conversion

AbstractWe evaluated the association between 16S rRNA gene (rrs) mutations and susceptibility in clinical isolates of amikacin-resistant nontuberculous mycobacteria (NTM) in NTM-pulmonary disease (PD) patients. Susceptibility was retested for 134 amikacin-resistant isolates (minimum inhibitory concentration [MIC] ≥ 64 µg/ml) from 86 patients. Amikacin resistance was reconfirmed in 102 NTM isolates from 62 patients with either Mycobacterium avium complex-PD (MAC-PD) (n = 54) or M. abscessus-PD (n = 8). MICs and rrs mutations were evaluated for 318 single colonies from these isolates. For the 54 MAC-PD patients, rrs mutations were present in 34 isolates (63%), comprising all 31 isolates with amikacin MICs ≥ 128 µg/ml, but only three of 23 isolates with an MIC = 64 µg/ml. For the eight M. abscessus-PD patients, all amikacin-resistant (MIC ≥ 64 µg/ml) isolates had rrs mutations. In amikacin-resistant isolates, the A1408G mutation (n = 29) was most common. Two novel mutations, C1496T and T1498A, were also identified. The culture conversion rate did not differ by amikacin MIC. Overall, all high-level and 13% (3/23) of low-level amikacin-resistant MAC isolates had rrs mutations whereas mutations were present in all amikacin-resistant M. abscessus isolates. These findings are valuable for managing MAC- and M. abscessus-PD and suggest the importance of phenotypic and genotypic susceptibility testing.

Download Full-text

Genotyping pattern of the vacuolating cytotoxin A and cytotoxin associated gene A of the Helicobacter pylori strains detected in fecal samples of household dogs

Microbiology Research ◽

10.4081/mr.2017.7289 ◽

2017 ◽

Vol 8 (2) ◽

Author(s):

Asieh Bolandi ◽

Saam Torkan ◽

Iman Alavi

Keyword(s):

Helicobacter Pylori ◽

16S Rrna ◽

16S Rrna Gene ◽

Pcr Amplification ◽

Rrna Gene ◽

Fecal Samples ◽

The Status ◽

Cytotoxin Associated Gene A ◽

H Pylori

In despite of the high clinical impact of Helicobacter pylori, its exact sources and routes of transmission are unknown. Dogs may play an imperative role in the transmission of H. pylori to humans. The current investigation was done to study the status of vacA and cagA genotypes in the H. pylori strains of dogs. One-hundred and fifty fecal samples were collected from healthy and complicated household dogs. Genomic DNA was extracted from fecal samples and presence of 16S rRNA gene was studied using the PCR amplification. Distribution of vacA and cagA genotypes were studied by the multiplex PCR. Thirteen out of 150 fecal samples (8.66%) were positive for H. pylori 16S rRNA gene. Prevalence of H. pylori in healthy and complicated dogs were 5.55% and 8.57%, respectively. Male had the higher prevalence of H. pylori (P=0.038). The most commonly detected genotypes among the H. pylori strains were vacAs1A (61.53%), cagA (38.46%), vacAm1a (38.46%), vacAs2 (30.76%) and vacAm2 (30.76%). The most commonly detected combined genotypes were s1aCagA (30.76%), s1am1a (23.07%), s2m1a (23.07%) and s2CagA (23.07%). Iranian household dogs harbor H. pylori in their fecal samples similar in genotypes of the vacA and cagA alleles which suggest that complicated and even healthy dogs may be the latent host of the H. pylori and its genotypes. However, supplementary studies are required to found the exact role of dogs as a definitive host of the H. pylori.

Download Full-text

Lack of Association between Helicobacter pylori Infection and Biliary Tract Diseases

Polish Journal of Microbiology ◽

10.33073/pjm-2012-044 ◽

2012 ◽

Vol 61 (4) ◽

pp. 319-322 ◽

Cited By ~ 4

Author(s):

SOMAYEH JAHANI SHERAFAT ◽

ELAHE TAJEDDIN ◽

MOHAMMAD REZA SEYYED MAJIDI ◽

FARZAM VAZIRI ◽

MASOUD ALEBOUYEH ◽

...

Keyword(s):

Helicobacter Pylori ◽

16S Rrna ◽

16S Rrna Gene ◽

Biliary Tract ◽

Helicobacter Pylori Infection ◽

Rrna Gene ◽

Biliary Tract Diseases ◽

Hepatobiliary Diseases ◽

H Pylori ◽

Bile Samples

There are ambiguous results about the involvement of Helicobacter species in production of hepatobiliary diseases. This study was aimed to investigate any possible association between the presences of Helicobacter spp., their genotypes and occurrence of different biliary diseases. Cultures of 102 bile samples for Helicobacter spp. did not show any growth, but the presence of Helicobacter genus specific DNA (16s rRNA gene) was detected in 3.92% of them. No significant association was found between development of the diseases and presence of the bacteria. All the Helicobacter genus positive samples belonged to H. pylori species and showed vacA+ (s1/m2), cagA- genotypes.

Download Full-text

Helicobacter pylori in water systems for human use in Mexico City

Water Science & Technology ◽

10.2166/wst.2001.0718 ◽

2001 ◽

Vol 43 (12) ◽

pp. 93-98 ◽

Cited By ~ 30

Author(s):

M. Mazari-Hiriart ◽

Y. López-Vidal ◽

J. J. Calva

Keyword(s):

Helicobacter Pylori ◽

16S Rrna ◽

16S Rrna Gene ◽

Mexico City ◽

Water Samples ◽

Water Systems ◽

Treated Wastewater ◽

Rrna Gene ◽

H Pylori ◽

System 1

Helicobacter pylori infection is associated with peptic ulcers and gastric cancer in humans. Transmission of H. pylori is still not certain with some epidemiological data suggesting water as a possible transmission route. The objective of this study was to detect H. pylori 16S rRNA gene in five water systems in the Mexico City area. Samples were taken between 1997 and 2000 from extraction wells (system 1), from dams used as water sources, both pre- and post-treatment (systems 2 and 3), treated wastewater (system 4) and non-treated wastewater (system 5). Detection of the H. pylori 16S rRNA gene in water samples was carried out using nested PCR in 139 water samples and confirmed by using cagA gene detection by PCR-hybridisation. The results showed the presence of H. pylori in 58 (42%) of the water samples in total with a prevalence of 68% in system 1, 100% in system 2, 0% in system 3, 17% in system 4 and 20% in system 5. This first stage showed the presence of H. pylori in the tested water systems; nevertheless, viability of the microorganism in water and vegetables needs to be confirmed as well as demonstration of a relationship between human and environmental strains.

Download Full-text

Evaluation of 16S rRNA gene PCR with primers Hp1 and Hp2 for detection of Helicobacter pylori.

Journal of Clinical Microbiology ◽

10.1128/jcm.34.11.2728-2730.1996 ◽

1996 ◽

Vol 34 (11) ◽

pp. 2728-2730 ◽

Cited By ~ 9

Author(s):

S K Chong ◽

Q Lou ◽

J F Fitzgerald ◽

C H Lee

Keyword(s):

Helicobacter Pylori ◽

16S Rrna ◽

16S Rrna Gene ◽

Rrna Gene

Download Full-text

Molecular Phylogenetic Analysis of 16S rRNA Sequences Identified Two Lineages of Helicobacter pylori Strains Detected from Different Regions in Sudan Suggestive of Differential Evolution

International Journal of Microbiology ◽

10.1155/2020/8825718 ◽

2020 ◽

Vol 2020 ◽

pp. 1-12

Author(s):

Abeer Babiker Idris ◽

Hadeel Gassim Hassan ◽

Maryam Atif Salaheldin Ali ◽

Sulafa Mohamed Eltaher ◽

Leena Babiker Idris ◽

...

Keyword(s):

Phylogenetic Analysis ◽

Helicobacter Pylori ◽

16S Rrna ◽

16S Rrna Gene ◽

Human Migration ◽

Rrna Gene ◽

Migration Patterns ◽

H Pylori ◽

Rrna Sequences ◽

16S Rrna Sequences

Background. Helicobacter pylori (H. pylori) is ubiquitous among humans and one of the best-studied examples of an intimate association between bacteria and humans. Phylogeny and Phylogeography of H. pylori strains are known to mirror human migration patterns and reflect significant demographic events in human prehistory. In this study, we analyzed the molecular evolution of H. pylori strains detected from different tribes and regions of Sudan using 16S rRNA gene and the phylogenetic approach. Materials and methods. A total of 75 gastric biopsies were taken from patients who had been referred for endoscopy from different regions of Sudan. The DNA extraction was performed by using the guanidine chloride method. Two sets of primers (universal and specific for H. pylori) were used to amplify the 16S ribosomal gene. Sanger sequencing was applied, and the resulted sequences were matched with the sequences of the National Center for Biotechnology Information (NCBI) nucleotide database. The evolutionary aspects were analyzed using MEGA7 software. Results. Molecular detection of H. pylori has shown that 28 (37.33%) of the patients were positive for H. pylori and no significant differences were found in sociodemographic characteristics, endoscopy series, and H. pylori infection. Nucleotide variations were observed at five nucleotide positions (positions 219, 305, 578, 741, and 763–764), and one insertion mutation (750_InsC_751) was present in sixty-seven percent (7/12) of our strains. These six mutations were detected in regions of the 16S rRNA not closely associated with either tetracycline or tRNA binding sites; 66.67% of them were located in the central domain of 16S rRNA. The phylogenetic analysis of 16S rRNA sequences identified two lineages of H. pylori strains detected from different regions in Sudan. The presence of Sudanese H. pylori strains resembling Hungarian H. pylori strains could reflect the migration of Hungarian people to Sudan or vice versa. Conclusion. This finding emphasizes the significance of studying the phylogeny of H. pylori strains as a discriminatory tool to mirror human migration patterns. In addition, the 16S rRNA gene amplification method was found useful for bacterial identification and phylogeny.

Download Full-text