scholarly journals Restriction Profiling of 23S Microheterogenic Ribosomal Repeats for Detection and Characterizing ofE. coliand Their Clonal, Pathogenic, and Phylogroups

2015 ◽  
Vol 2015 ◽  
pp. 1-11
Author(s):  
Parvathi Jayasree Rajagopalan Nair ◽  
Sunita Singh

Correlating ribosomal microheterogenicity with unique restriction profiles can prove to be an efficacious and cost-effective approach compared with sequencing for microbial identification. An attempt to peruse restriction profiling of 23S ribosomal assemblage was ventured; digestion patterns withBfaI discriminatedE. colifrom its colony morphovars, whileHaeIII profiles assisted in establishing distinct clonal groups. Among the gene pool of 399 ribosomal sequences extrapolated from 57E. coligenomes, varying degree of predominance (I > III > IV > II) ofHaeIII pattern was observed. This was also corroborated in samples collected from clinical, commensal, and environmental origin. K-12 and its descendants showed type I pattern whereasE. coli-B and its descendants exhibited type IV, both of these patterns being exclusively present inE. coli. A near-possible association between phylogroups andHaeIII profiles with presumable correlation between the clonal groups and different pathovars was established. The generic nature, conservation, and barcode gap of 23S rRNA gene make it an ideal choice and substitute to 16S rRNA gene, the most preferred region for molecular diagnostics in bacteria.

2005 ◽  
Vol 49 (7) ◽  
pp. 2753-2759 ◽  
Author(s):  
Amera Gibreel ◽  
Veronica N. Kos ◽  
Monika Keelan ◽  
Cathy A. Trieber ◽  
Simon Levesque ◽  
...  

ABSTRACT A collection of 23 macrolide-resistant Campylobacter isolates from different geographic areas was investigated to determine the mechanism and stability of macrolide resistance. The isolates were identified as Campylobacter jejuni or Campylobacter coli based on the results of the hippurate biochemical test in addition to five PCR-based genotypic methods. Three point mutations at two positions within the peptidyl transferase region in domain V of the 23S rRNA gene were identified. About 78% of the resistant isolates exhibited an A→G transition at Escherichia coli equivalent base 2059 of the 23S rRNA gene. The isolates possessing this mutation showed a wide range of erythromycin and clarithromycin MICs. Thus, this mutation may incur a greater probability of treatment failure in populations infected by resistant Campylobacter isolates. Another macrolide-associated mutation (A→C transversion), at E. coli equivalent base 2058, was detected in about 13% of the isolates. An A→G transition at a position cognate with E. coli 23S rRNA base 2058, which is homologous to the A2142G mutation commonly described in Helicobacter pylori, was also identified in one of the C. jejuni isolates examined. In the majority of C. jejuni isolates, the mutations in the 23S rRNA gene were homozygous except in two cases where the mutation was found in two of the three copies of the target gene. Natural transformation demonstrated the transfer of the macrolide resistance phenotype from a resistant Campylobacter isolate to a susceptible Campylobacter isolate. Growth rates of the resulting transformants containing A-2058→C or A-2059→G mutations were similar to that of the parental isolate. The erythromycin resistance of six of seven representative isolates was found to be stable after successive subculturing in the absence of erythromycin selection pressure regardless of the resistance level, the position of the mutation, or the number of the mutated copies of the target gene. One C. jejuni isolate showing an A-2058→G mutation, however, reverted to erythromycin and clarithromycin susceptibility after 55 subcultures on erythromycin-free medium. Investigation of ribosomal proteins L4 and L22 by sequence analysis in five representative isolates of C. jejuni and C. coli demonstrated no significant macrolide resistance-associated alterations in either the L4 or the L22 protein that might explain either macrolide resistance or enhancement of the resistance level.


2014 ◽  
Vol 59 (2) ◽  
pp. 1048-1051 ◽  
Author(s):  
Zibo Zhou ◽  
Xiangzhi Li ◽  
Xiaojian Chen ◽  
Fangjun Luo ◽  
Changwang Pan ◽  
...  

ABSTRACTMycoplasma pneumoniaeis a major pathogen causing community-acquired pneumoniae (CAP), which is generally treated with macrolides. In recent years, however, although macrolide-resistantM. pneumoniaehas been reported frequently, particularly in China, very little is known about the prevalence of macrolide-resistantM. pneumoniaeinfection in adults. In this study, we survey the macrolide-resistantM. pneumoniaein adults in Zhejiang province and characterize the mechanisms of resistance to macrolide. Six hundred fifty throat swab samples were collected from adult patients with CAP from January 2012 to August 2014. These samples were assayed by nested PCR and then cultivated forM. pneumoniae. All isolates were sequenced to determine the mutation in domain V of the 23S rRNA gene. The activities of 10 antibiotics against macrolide-resistantM. pneumoniaeisolates were also investigatedin vitro. Moreover, restriction fragment length polymorphism (RFLP) analysis of the amplified P1 gene was used to type 50 resistant strains. One hundred percent (71/71) ofM. pneumoniaestrains isolated from adults with CAP were resistant to erythromycin (MIC = 128 to >256 μg/ml), clarithromycin (MIC = 128 to >256 μg/ml), and azithromycin (MIC = 32 to >64 μg/ml). Furthermore, all macrolide-resistantM. pneumoniaestrains identified had an A2063G mutation in domain V of the 23S rRNA gene. Forty-six resistant strains (92.0%) were classified into type I strain on the basis of P1 gene PCR-RFLP analysis. According to these findings, it is suggested that macrolide-resistantM. pneumoniaeinfection is very prevalence among adults in Zhejiang province. Thus, there is necessary to perform the epidemiological monitoring of macrolide-resistantM. pneumoniaein the future.


Pathogens ◽  
2020 ◽  
Vol 9 (8) ◽  
pp. 622 ◽  
Author(s):  
Andrea Kinnear ◽  
Tim A. McAllister ◽  
Rahat Zaheer ◽  
Matthew Waldner ◽  
Antonio C. Ruzzini ◽  
...  

Mycoplasma bovis is associated with bovine respiratory disease (BRD) and chronic pneumonia and polyarthritis syndrome (CPPS) in feedlot cattle. No efficacious vaccines for M. bovis exist; hence, macrolides are commonly used to control mycoplasmosis. Whole genome sequences of 126 M. bovis isolates, derived from 96 feedlot cattle over 12 production years, were determined. Antimicrobial susceptibility testing (AST) of five macrolides (gamithromycin, tildipirosin, tilmicosin, tulathromycin, tylosin) was conducted using a microbroth dilution method. The AST phenotypes were compared to the genotypes generated for 23S rRNA and the L4 and L22 ribosomal proteins. Mutations in domains II (nucleotide 748; E. coli numbering) and V (nucleotide 2059 and 2060) of the 23S rRNA (rrl) gene alleles were associated with resistance. All isolates with a single mutation at Δ748 were susceptible to tulathromycin, but resistant to tilmicosin and tildipirosin. Isolates with mutations in both domain II and V (Δ748Δ2059 or Δ748Δ2060) were resistant to all five macrolides. However, >99% of isolates were resistant to tildipirosin and tilmicosin, regardless of the number and positions of the mutations. Isolates with a Δ748 mutation in the 23S rRNA gene and mutations in L4 and L22 were resistant to all macrolides except for tulathromycin.


2011 ◽  
Vol 56 (2) ◽  
pp. 1108-1109 ◽  
Author(s):  
Fei Zhao ◽  
Min Lv ◽  
Xiaoxia Tao ◽  
Hui Huang ◽  
Binghua Zhang ◽  
...  

ABSTRACTMICs of eight antibiotics were detected with 40 ChineseMycoplasma pneumoniaeisolates. Thirty-eight isolates (95%) were macrolide resistant. Each macrolide-resistant isolate harbored an A2063G or A2064G point mutation in the 23S rRNA gene. All 40 isolates (100%) were type I strains, but they might have originated from different clones.


2016 ◽  
Vol 10 (08) ◽  
pp. 807-813 ◽  
Author(s):  
Ahmed M Ammar ◽  
Norhan K Abd El-Aziz ◽  
Ahlam A Gharib ◽  
Hanaa K Ahmed ◽  
Amira E Lameay

Introduction: Avian mycoplasmas impose a significant economic burden to the poultry industry. In recent years, macrolide-resistant Mycoplasma gallisepticum have occasionally been encountered in Egypt. Methodology: This study was designed to document the involvement of macrolide-resistant M. gallisepticum in respiratory organs of chickens suffering respiratory problems. Concurrently, an exhaustive molecular characterization of the intrinsic resistance of recovered isolates to macrolides was done. Results: Of 120 chickens showing respiratory problems, 14 (11.67%) M. gallisepticum were isolated and genetically identified; 8 of them were recovered from air sacs, 4 from lungs, and 2 from tracheas. Broth microdilution of all M. gallisepticum isolates showed various degrees of minimum inhibitory concentrations (MICs) against macrolides: erythromycin (0.25–32 µg/mL), tylosin (0.0625–4 µg/mL), and tiamulin (0.031–2 µg/mL). Nucleotide sequencing of domain V (peptidyl transferase region) of the 23S rRNA gene of macrolide-resistant M. gallisepticum isolates revealed transition mutations at positions 2068 and 2069 (corresponding to 2058 and 2059 in Escherichia coli numbering) in an isolate and at position 2067 (corresponding to 2057 in E. coli numbering) in three isolates as hot spots for macrolide resistance. Surprisingly, a transversion mutation at position 2621 (corresponding to 2611 in E. coli numbering) was reported in one of the recovered isolates as a first report. Conclusion: Generation of new mutations is evidence for persistence of M. gallisepticum despite macrolide treatment. Periodic surveys to monitor for the possible appearance of resistant strains are recommended.


1998 ◽  
Vol 42 (8) ◽  
pp. 1952-1958 ◽  
Author(s):  
Ge Wang ◽  
Diane E. Taylor

ABSTRACT Clarithromycin resistance in Helicobacter pylori is mainly due to A-to-G mutations within the peptidyltransferase region of the 23S rRNA. In the present study, cross-resistance to macrolide, lincosamide, and streptogramin B (MLS) antibiotics (MLS phenotypes) has been investigated for several clinical isolates of H. pylori. Two major types of MLS resistance were identified and correlated with specific point mutations in the 23S rRNA gene. The A2142G mutation was linked with high-level cross-resistance to all MLS antibiotics (type I), and the A2143G mutation gave rise to an intermediate level of resistance to clarithromycin and clindamycin but no resistance to streptogramin B (type II). In addition, streptogramin A and streptogramin B were demonstrated to have a synergistic effect on both MLS-sensitive and MLS-resistant H. pyloristrains. To further understand the mechanism of MLS resistance inH. pylori, we performed in vitro site-directed mutagenesis (substitution of G, C, or T for A at either position 2142 or 2143 of the 23S rRNA gene). The site-directed point mutations were introduced into a clarithromycin-susceptible strain, H. pylori UA802, by natural transformation followed by characterization of their effects on MLS resistance in an isogenic background. Strains with A-to-G and A-to-C mutations at the same position within the 23S rRNA gene had similar levels of clarithromycin resistance, and this level of resistance was higher than that for strains with the A-to-T mutation. Mutations at position 2142 conferred a higher level of clarithromycin resistance than mutations at position 2143. All mutations at position 2142 conferred cross-resistance to all MLS antibiotics, which corresponds to the type I MLS phenotype, whereas mutations at position 2143 were associated with a type II MLS phenotype with no resistance to streptogramin B. To explain that A-to-G transitions were predominantly observed in clarithromycin-resistant clinical isolates, we propose a possible mechanism by which A-to-G mutations are preferentially produced in H. pylori.


Author(s):  
J G E Laumen ◽  
S S Manoharan-Basil ◽  
E Verhoeven ◽  
S Abdellati ◽  
I De Baetselier ◽  
...  

Abstract Background The prevalence of azithromycin resistance in Neisseria gonorrhoeae is increasing in numerous populations worldwide. Objectives To characterize the genetic pathways leading to high-level azithromycin resistance. Methods A customized morbidostat was used to subject two N. gonorrhoeae reference strains (WHO-F and WHO-X) to dynamically sustained azithromycin pressure. We tracked stepwise evolution of resistance by whole genome sequencing. Results Within 26 days, all cultures evolved high-level azithromycin resistance. Typically, the first step towards resistance was found in transitory mutations in genes rplD, rplV and rpmH (encoding the ribosomal proteins L4, L22 and L34 respectively), followed by mutations in the MtrCDE-encoded efflux pump and the 23S rRNA gene. Low- to high-level resistance was associated with mutations in the ribosomal proteins and MtrCDE efflux pump. However, high-level resistance was consistently associated with mutations in the 23S ribosomal RNA, mainly the well-known A2059G and C2611T mutations, but also at position A2058G. Conclusions This study enabled us to track previously reported mutations and identify novel mutations in ribosomal proteins (L4, L22 and L34) that may play a role in the genesis of azithromycin resistance in N. gonorrhoeae.


Author(s):  
Konrad Egli ◽  
Anna Roditscheff ◽  
Ursula Flückiger ◽  
Martin Risch ◽  
Lorenz Risch ◽  
...  

Abstract Background The resistance of Neisseria gonorrhoeae to ceftriaxone is unusual in Switzerland. The underlying genotype responsible for resistance is suspected to be novel. Generally, resistance in Neisseria gonorrhoeae (Ng) involves a comprehensive set of genes with many different mutations leading to resistance to different β-lactams and fluoroquinolones. Case presentation A patient had a positive result from specific PCR for Ng. We routinely culture all clinical specimens with a positive NG-PCR. In this particular case, we isolated a strain with resistance to ceftriaxone in Switzerland. A total of seven different genes (penA, ponA, porinB, mtr, gyrA, parC, 23S rRNA gene) in this strain were partially sequenced for comparison with phenotypic susceptibility testing. Interestingly, two different mutations in the porinB gene were observed, and data on this gene are limited. Information on the identified allele type of the penA gene is very limited as well. Three different mutations of parC and gyrA that correlate with ciprofloxacin resistance were found. The combination of ceftriaxone and ciprofloxacin resistance makes an appropriate treatment difficult to obtain due to multidrug resistance. Conclusion The combined results for all genes show the appearance of new mutations in central Europe either due to worldwide spread or the emergence of new genetic combinations of mutations.


2018 ◽  
Vol 2018 ◽  
pp. 1-9 ◽  
Author(s):  
Bai Wei ◽  
Min Kang

We investigated the molecular mechanisms underlying macrolide resistance in 38 strains ofCampylobacterisolated from poultry. Twenty-seven strains were resistant to azithromycin and erythromycin, five showed intermediate azithromycin resistance and erythromycin susceptibility, and six showed azithromycin resistance and erythromycin susceptibility. FourCampylobacter jejuniand sixCampylobacter colistrains had azithromycin MICs which were 8–16 and 2–8-fold greater than those of erythromycin, respectively. The A2075G mutation in the 23S rRNA gene was detected in 11 resistant strains with MICs ranging from 64 to ≥ 512μg/mL. Mutations including V137A, V137S, and a six-amino acid insertion (114-VAKKAP-115) in ribosomal protein L22 were detected in theC. jejunistrains. Erythromycin ribosome methylase B-erm(B) was not detected in any strain. All strains except three showed increased susceptibility to erythromycin with twofold to 256-fold MIC change in the presence of phenylalanine arginine ß-naphthylamide (PAßN); the effects of PAßN on azithromycin MICs were limited in comparison to those on erythromycin MICs, and 13 strains showed no azithromycin MIC change in the presence of PAßN. Differences between azithromycin and erythromycin resistance and macrolide resistance phenotypes and genotypes were observed even in highly resistant strains. Further studies are required to better understand macrolide resistance inCampylobacter.


2013 ◽  
Vol 76 (8) ◽  
pp. 1451-1455 ◽  
Author(s):  
KINGA WIECZOREK ◽  
IWONA KANIA ◽  
JACEK OSEK

The purpose of the present study was to determine the prevalence of Campylobacter in poultry carcasses at slaughter in Poland. For the isolated strains, resistance to selected antibiotics and the associated genetic determinants were identified. A total of 498 Campylobacter isolates were obtained from 802 poultry samples during the 2-year study period. Strains were identified to species with the PCR method; 53.6% of the strains were Campylobacter jejuni and 46.4% were Campylobacter coli. A high percentage of the tested Campylobacter strains were resistant to ciprofloxacin and nalidixic acid (74.1 and 73.5%, respectively) followed by tetracycline (47.4%) and streptomycin (20.5%). Only one C. jejuni and two C. coli isolates were resistant to gentamicin. Seventy-nine (15.9%) of the 498 strains were resistant to three or more classes of antibiotics examined. Higher levels of resistance, irrespective of the antimicrobial agent tested, were found within the C. coli group. Almost all strains resistant to quinolones (99.5%) and to tetracycline (99.6%) carried the Thr-86-to-Ile mutation in the gyrA gene and possessed the tet(O) marker, respectively. All isolates resistant to erythromycin had the A2075G mutation in the 23S rRNA gene. These results reveal that poultry carcasses in Poland are a reservoir of potentially pathogenic and antimicrobial-resistant Campylobacter strains for humans, which may pose a public health risk.


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