CMAC 2018; Vol. 20(1) : Contents
20(1): 1-72

Clinical Microbiology and Antimicrobial Chemotherapy. 2018; vol. 20, N 1: 1-72

Diseases and Pathogens

Clinical Microbiology and Antimicrobial Chemotherapy 2018; 20(1):5-8

Vaccination against pneumococcal infections in adults

Resolution of the expert council (Moscow, 16 December 2017)

Kozlov R.S., Avdeev S.N., Briko N.I., Bilichenko T.N., Kostinov M.P., Sidorenko S.V., Kharit S.M., Sinopalnikov A.I., Zaitsev A.A., Shubin I.V., Demko I.V., Ignatova G.L., Ratchina S.A., Feldblum I.V.

The following key issues of pneumococcal infection prophylaxis were discussed during the expert council: incidence rates of community-acquired pneumococcal pneumonia and other pneumococcal infections, local epidemiological data, increases in antimicrobial resistance and pneumococcal serotypes substitution, current international and Russian clinical guidelines, practical approaches, and pneumococcal vaccination coverage of adult population in the Russian Federation. The agreement between the experts about a need to distinguish the use of conjugate vaccines and polysaccharide vaccines in different subpopulations has been achieved.

pneumococcal infection, vaccines, adults, pneumococcal polysaccharide vaccine

 

Clinical Microbiology and Antimicrobial Chemotherapy 2018; 20(1):10-13

Vaccines for travel and vaccines for adults: moving targets!

McIntosh E. David G.

This short review provides up-to-date information on vaccination problems for travelers and adults in general, including hepatitis B, meningococcal infection, rabies, yellow fever, measles. The article presents the general principles of approaches to vaccination with a focus on those diseases and potential prospects for solving this problem.

vaccination, travelers, adults

 

Clinical Microbiology and Antimicrobial Chemotherapy 2018; 20(1):14-23

Biological characteristics and virulence of Helicobacter pylori

Isaeva G.Sh., Valieva R.I.

This review summarizes the most recent data on the biological characteristics of Helicobacter pylori (morphological, cultural, biochemical). H. pylori pathogenicity factors promoting colonization, adhesion, biofilm formation, aggression, and cytotoxicity, their contribution to the pathogenesis of diseases as well as the possible relationships with various clinical outcomes are described in detail. The genetic heterogeneity of H. pylori strains which can determine different clinical manifestations and have significance for conducting epidemiological studies is also considered.

Helicobacter pylori, pathogenicity factors, virulence, cytotoxicity, adhesion, biofilm, heterogeneity


Antimicrobials

Clinical Microbiology and Antimicrobial Chemotherapy 2018; 20(1):24-34

Ceftazidime-avibactam: new rules for the game against multidrug-resistant Gram-negative bacteria

Kozlov R.S., Stetsiouk O.U., Andreeva I.V.

The rapid spread of multidrug-resistant Gram-negative bacteria in hospital settings all over the world makes a demand for the new options to overcome antimicrobial resistance. Ceftazidime-avibactam is the first approved antibiotic that contains a new beta-lactamase inhibitor with unique properties. This review provides insight into the spectrum of activity, pharmacological characteristics, data on efficacy and safety of ceftazidime-avibactam obtained from the clinical trials and real clinical practice, as well as prospects for further studies and clinical application of this new antimicrobial agent.

Gram-negative bacteria, multidrug resistance, beta-lactamase inhibitor, ceftazidime-avibactam

 

Clinical Microbiology and Antimicrobial Chemotherapy 2018; 20(1):35-40

Daptomycin in the treatment of infective endocarditis

Popov D.A.

This review characterizes daptomycin as a highly effective lipopeptide antibiotic being active against Gram-positive microorganisms, including multidrug resistant strains. The data reflecting the up-to-date daptomycin-based approaches to antimicrobial therapy of infective endocarditis which utilize this drug advantages over standard treatment regimens are presented. The data presented are illustrated with clinical cases.

infective endocarditis, daptomycin, treatment


Antimicrobial Resistance

Clinical Microbiology and Antimicrobial Chemotherapy 2018; 20(1):42-48

Antimicrobial resistance of Helicobacter pylori in Smolensk

Dekhnich N.N., Ivanchik N.V., Kozlov R.S., Alimov A.V., Steshits A.S., Kirsov P.P.

Objective. To study the antimicrobial resistance of H. pylori to clarithromycin, amoxicillin, metronidazole, levofloxacin, tetracycline in adult patients in the Smolensk region.

Materials and methods. Overall, 573 adult patients were included in 2015-2017 and 210 — in 2009-2010 with positive rapid urease test at the time of gastroscopy for dyspeptic complaints. Antimicrobial susceptibility testing of H. pylori isolates to clarithromycin, amoxicillin, metronidazole, levofloxacin and tetracycline was performed by the agar dilution method.

Results. 143 and 133 strains of H. pylori isolated in 2015-2017 and in 2009-2010 were tested. The rates of resistance of H. pylori strains in 2015-2017 were 6.3% for clarithromycin, 1.4% — for amoxicillin, 23.8% — for metronidazole, 24.5% — for levofloxacin, 0.7% — for tetracycline. In 2009-2010 the corresponding numbers were: 5.3% — for clarithromycin, 4.5% — for amoxicillin, 3.8% — for metronidazole, 8.3% — for levofloxacin, 0% — for tetracycline. When assessing the dynamics of antimicrobial resistance of H. pylori in the Smolensk region over the past 9 years, there has been no noticeable increase in the resistance to clarithromycin, amoxicillin and tetracycline (p>0.05), with a significant increase in H. pylori resistance to metronidazole and levofloxacin (p<0,01). The resistance of H. pylori to metronidazole did not exceed the critical value of 40%.

Conclusions. The prevalence of H. pylori resistance to clarithromycin and metronidazole in the Smolensk region was low throughout the study period, therefore standard triple therapy is recommended as a first line empirical therapy for H. pylori infection in adults. Preference in choosing a second-line empirical therapy between quadruple therapy with bismuth and triple therapy with levofloxacin should be stated in favor of quadruple therapy with bismuth because of the high rates of H. pylori resistance to levofloxacin.

Helicobacter pylori, antimicrobial resistance, clarithromycin, amoxicillin, metronidazole, levofloxacin

 

Clinical Microbiology and Antimicrobial Chemotherapy 2018; 20(1):49-54

Susceptibility testing of Candida glabrata clinical strains to echinocandins using Sensititre™ YeastOne™ system

Veselov A.V., Vasilyeva N.V., Bogomolova T.S., Raush E.R., Kutsevalova O.Yu., Nizhegorodtseva I.A., Petrova L.V., Shmidt N.V., Moskvitina E.N., Sukhorukova M.V., Ivanchik N.V., Kozlov R.S.

Objective. To determine susceptibility of C. glabrata isolates to anidulafungin, caspofungin and micafungin using the Sensititre™ YeastOne™ system

Materials and methods. C. glabrata isolates were taken prospectively from clinical specimens or from strains collections in the participating sites. Susceptibility determination was performed using Sensititre™ YeastOne™ (YO10 panel) according to the manufacturer’s guidance, and results were interpreted with M27-A3 CLSI guidelines. Susceptibility of C. glabrata to fluconazole was also determined in order to assess possible correlations of echinocandins and fluconazole minimal inhibitory concentrations (MICs) in resistant strains.

Results. A total of 59 C. glabrata strains were tested. The strains were isolated mostly from peripheral blood (44%). Among clinically significant medical conditions/risk factors and co-morbidities, central venous catheter, solid tumors, and abdominal surgery were identified in 20 (33.9%), 19 (32.2%), and 14 (23.7%) patients, respectively. Most MIC values of echinocandins were 0.015 and 0.03 mg/L. Caspofungin has slightly higher MIC values than those of anidulafungin and micafungin. No isolates were resistant to any of the echinocandins. The only 2 patients were receiving echinocandin therapy at the time of taking biosamples (with no reported information about treatment efficacy); those strains were also susceptible to all echinocandins. All C. glabrata strains were susceptible dose-dependent to fluconazole with MIC values between 2 and 32 mg/L.

Conclusions. All of the echinocandins have a high and comparable in vitro activity against C. glabrata, including strains which are susceptible dose-depended to fluconazole. More prospective studies are needed to investigate the long-term trends in susceptibility profiles of pathogens causing candidiasis, especially C. glabrata.

Candida glabrata, candidiasis, echinocandins, resistance

 

Clinical Microbiology and Antimicrobial Chemotherapy 2018; 20(1):55-61

Detection of vancomycin-resistant enterococci using chromogenic selective medium

Fyodorova A.V., Klyasova G.A.

Objective. To detect vancomycin-resistant enterococci (VRE) using chromogenic selective medium CHROMagar™VRE (CHROMagar, France).

Materials and methods. In the first part of the study, a total of 39 vancomycin-resistant and 20 vancomycinsusceptible Enterococcus spp. isolated from blood culture with known susceptibility profiles were incubated on the CHROMagar™VRE (CHROMagar, France) and examined after 24 h and 48 h of incubation. In the second part of the study, a total of 110 rectal swabs were taken from patients with hematological malignancies and incubated on the CHROMagar™VRE. The vancomycin susceptibility of isolates grown on the selective medium was further evaluated by the broth microdilution method (CLSI, 2017). Glycopeptide resistance genes were detected by PCR.

Results. Using the CHROMagar™VRE, a total of 36 (92.3%) vancomycin-resistant isolates were detected after 24 h and additional two isolates — after 48 h of incubation. The sensitivity of the selective medium for detection of VRE obtained from blood culture was 92% and 97% after 24 h and 48 h of incubation, respectively. All 20 vancomycin-susceptible enterococci did not grow on the CHROMagar™VRE (specificity — 100%). Of 110 rectal swabs, 35 (31.8%) samples were positive for Enterococcus spp. on the CHROMagar™VRE (33 — E. faecium and 2 — E. faecalis). Resistance to vancomycin was detected in 32/33 (97%) E. faecium isolates, of them 28 and 4 strains were isolated after 24 h and 48 h of incubation; all VRE strains carried vanA gene. The proportion of false positive isolates was 3.4% after 24 h of incubation and 8.6% after 48 h of incubation on the CHROMagar™VRE medium for screening of VRE from rectal swabs.

Conclusions. The chromogenic selective media CHROMagar™VRE has a high sensitivity and specificity for the detection of VRE and can be used for screening in laboratory practice.

chromogenic selective medium, vancomycin-resistance enterococci, Enterococcus faecium, antimicrobial resistance


Personal Experience

Clinical Microbiology and Antimicrobial Chemotherapy 2018; 20(1):62-67

Antimicrobial susceptibility testing by broth microdilution method: widely available modification

Tapalskiy D.V., Bilskiy I.A.

Objective. To assess the possibility of standard disk application as an antibiotic source for determination of the minimal inhibitory concentrations (MICs) by serial microdilution method.

Materials and methods. A simple method of working solutions preparation using standard paper discs as an antibiotics source available in most microbiological laboratories is proposed. A multiple determination of antibiotic MICs for E. coli ATCC 25922 and P. aeruginosa ATCC 27853 strains was conducted.

Results. Of the 576 MIC values determined by the modified method, 78.5% of the results corresponded to the control strains reference values, and 20.8% of the results were categorized as acceptable values.

Conclusions. Use of standard disks as an antibiotics source for the working solutions preparation greatly simplifies a testing by serial microdilution method and makes it available to most microbiological laboratories.

minimal inhibitory concentration, disks with antibiotics, antimicrobial resistance

 

Clinical Microbiology and Antimicrobial Chemotherapy 2018; 20(1):68-72

Whole genome sequencing of Mycoplasma hominis strains resistant to ciprofloxacin

Kolesnikova E.A., Brusnigina N.F., Makhova M.A., Alekseeva A.E.

In order to determine molecular mechanisms of resistance to ciprofloxacin, clinical isolates of Mycoplasma hominis (2 strains) obtained from women with pelvic inflammatory disease were investigated. Whole genome sequencing was performed using a high-performance MiSeq sequencer (Illumina, USA). M. hominis M57 and M45 isolates were found to have the proportion of GC-bases which is typical for this species (27.2%). A high degree of the protein sequences homology of the M57 and M45 isolates has been determined. Phylogenetic analysis showed that the M57 isolate is evolutionarily closer to the PG21 isolate, and M45 is evolutionarily closer to H34. Analysis of the amino acid sequences of gyrA, gyrB, parC and parE genes in M45 and M57 isolates detected that the molecular mechanism of ciprofloxacin resistance is due to the presence of mutational changes in the QRDR of gyrA gene (DNA gyrase subunit A) leading to substitution of serine for leucine at the position 83. No mutations affecting the codons in the QRDR of gyrB, parC and parE genes were detected. Analysis of the gyrA, gyrB, parC and parE genes structure showed a high degree of polymorphism due to the high spontaneous mutations rate. The genomes of M. hominis M45 and M57 isolates found to carry genes of the MATE family efflux pumps, but their role in the development of antimicrobial resistance in M. hominis has not been proved experimentally to date.

Mycoplasma hominis, whole genome sequencing, resistance, ciprofloxacin, gyrA, mutation



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