Comparing mycobacterium tuberculosis complex susceptibility methods, a developing countrys experience

In spite of current diagnosis and treatment, Mycobacterium tuberculosis complex is still an important cause of mortality and morbidity. Uneffective drug combinations and patient incompliance lead to increasing drug resistance. This study by managing four different -non molecular- susceptibility methods was carried out to determine the susceptibility patterns of Mycobacterium tuberculosis complex isolates in central part of Turkey and to compare the methods. The susceptibility testing of 33 isolates were initially performed using the agar proportion method, the results of which were compared with the other three methods; BACTEC 460TB, MGIT 960, and Etest prospectively. According to the gold standard agar proportion method, none of the strains were resistant to STR or ETM, while two isolates were found to be resistant to both isoniazid and rifampicin. BACTEC 460 TB remains the reference method of choice, and for low-volume centers. The MGIT 960 system is more suited for high-volume laboratories but has a high risk of contamination. Etest may seem expensive and produces cumbersome results. Regardless of the test used, validation with the gold standard method should be performed periodically as well as in the event of a discordant result. There remains a need for further studies to establish whether available rapid tests will eventually become the gold standard. [Med-Science 2017; 6(2.000): 199-203

Comparison of steam technology and a two-step cleaning (water/detergent) and disinfecting (1,000 resp. 5,000 ppm hypochlorite) method using microfiber cloth for environmental control of multidrug-resistant organisms in an intensive care unit.

Aim: The aim of this prospective observational study was to evaluate the impact of two cleaning and disinfecting methods and the use of steam against methicillin-resistant Staphyl ococcus aureus , vancomycin-resistant Enterococcus faecalis , carbapenem-resistant Pseudomonas aeruginosa and multidrug-resistant (MDR) Acinetobacter baumannii in a tertiary referral hospital. Methods: McFarland 0.5 suspensions (content 1.5 x 108 cfu/ml) of four challenge bacterial species were prepared and used to inoculate different sites in three ICU rooms. One of the following methods was used in each room: steam technology (Tecnovap Evo 304) resp. cleaning with microfiber cloths, soaked with detergent and water, thereafter disinfection with 1,000 ppm hypochlorite or the same procedure with 5,000 ppm hypochlorite. Qualitative microbiology and ATP bioluminescence were performed before and after cleaning with each method. The Wilcoxon test was used for paired samples to check for ordinal variables. The cost of each cleaning method was analyzed. Results: Environmental cleaning with steam technology was found to be as effective against MDR microorganisms as a two-step cleaning process (water/detergent and disinfecting with 1,000 resp. 5,000 ppm hypochlorite) in ICUs. No bacterial growth was detected after any of the three cleaning methods. Steam technology was 76% and 91% cheaper than using 5,000 ppm and 1,000 ppm hypochlorite, respectively.Conclusions: When compared to, steam technology was found to have an advantage over the 2-step procedure with cleaning and disinfection, because it avoids the use of chemicals, reduces water consumption, labor time and costs for cleaning.Zielsetzung: In einer prospektiven Beobachtungsstudie sollte die Wirksamkeit von zwei Verfahren der desinfizierenden Reinigung bzw. der Anwendung von Dampf gegen Methicillin-resistente Staphylococcus aureus (MRSA), Vancomycin-resistente Enterococcus faecalis (VRE), Carbapenem-resistente Pseudomonas aeruginosa und multiresistente (MDR) Acinetobacter baumannii in einem Krankenhaus der Tertiärversorgung verglichen werden.Methode: Von den vier Bakterienspecies wurden Suspensionen mit einem Gehalt von 1,5 x 108 KbE/ml hergestellt und zur Kontamination von drei Lokalisationen in drei Intensivstationen eingesetzt. In jedem Raum wurde eine der folgenden Reinigungsmethoden angewendet: Dampftechnologie (Tecnovap Evo 304) oder 2 Formen der desinfizierenden Reinigung in zwei Schritten: zuerst Reinigung mit Tensid getränktem Mikrofasertuch, anschließend Wischdesinfektion mit 1.000 ppm oder analoges Vorgehen nur mit 5.000 ppm Hypochlorit. Vor und nach der desinfizierenden Reinigung wurde ein qualitativer Erregernachweis geführt und die Reinigungswirkung mittels ATP-Biolumineszenz gemessen. Der Wilcoxon-Test wurde für gepaarte Stichproben zur Überprüfung ordinaler Variablen verwendet. Die Kosten für jede Reinigungsmethode wurden analysiert.Ergebnisse: Die drei Verfahren erwiesen sich als gleich wirksam. Nach keiner der drei Reinigungsmethoden war ein Bakterienwachstum nachweisbar. Die Dampftechnologie war 76% bzw. 91% preiswerter als die Verwendung von 5.000 ppm bzw. 1.000 ppm Hypochlorit.Schlussfolgerung: Im Vergleich zur zweistufigen desinfizierenden Reinigung mit Chlorlösungen erwies sich die Dampftechnologie als vorteilhafter, da auf den Einsatz von Chemikalien verzichtet und der Verbrauch von Wasser, benötigter Arbeitszeit und Reinigungskosten reduziert wird

Antibiotic Susceptibilities and Serotyping of Clinical Streptococcus Agalactiae Isolates

Objective: Streptococcus agalactiae (Group B streptococci, GBS) are frequently responsible for sepsis and meningitis seen in the early weeks of life. GBS may cause perinatal infection and premature birth in pregnant women. The aim of this study was to serotype GBS strains isolated from clinical samples and evaluate their serotype distribution according to their susceptibilities to antibiotics and isolation sites

Comparative Evaluation of E-Test and Disk Diffusion Methods for Susceptibility Testing of Nocardia Species

Variations in antimicrobial susceptibility among different Nocardia species limit the options for therapy. It is very difficult to perform antimicrobial susceptibility testing of these bacteria due to their slow growth rate and problems in inoculum preparation. The aim of this study was to compare E-test and disk diffusion methods for the determination of antimicrobial susceptibilities of Nocardia isolates. Since E-test is considered as 90% consistent with the gold standard microdilution method recommended by Clinical and Laboratory Standards Institute (CLSI), it was chosen for comparison with disk diffusion and in order to determine the use of disk diffusion in routine practice. A total of 21 Nocardia strains isolated from clinical specimens (12 lung, 7 brain and 2 skin/soft tissue samples) were included in the study. Six of the isolates were identified as N.asteroides, six were N.farcinica, five were N.cyriacigeorgica and four were Nocardia spp. by conventional methods. Susceptibilities of strains to ampicillin, ampicillin-sulbactam, amoxicillin-clavulanic acid, ceftazidime, sefepime, imipenem, gentamicin, erythromycin, levofloxacin, moxifloxacin, trimethoprim-sulfamethoxazole, piperacillin-tazobactam, tigecycline, and linezolid were investigated by using E-test and/or disk diffusion methods. The results were interpreted according to the CLSI breakpoints for Staphylococcus spp. All of the strains were found to be resistant to ceftazidime, piperacillin-tazobactam and ampicillin, however susceptible to levofloxacin, moxifloxacin, trimethoprim-sulfamethoxazole tigecycline, and linezolid. The concordance between the methods in terms of susceptibility testing were 100% for ampicillin, ceftazidime, imipenem, gentamicin and linezolid; 85.7% for erythromycin, 76.2% for sefepime, 73.7% for moxifloxacin, 71.4% for piperacillin-tazobactam, 70% for ampicillin-sulbactam and 46.2% for amoxicillin-clavulanic acid. In conclusion, the therapy must be planned according to the results of antimicrobial susceptibility testing. Disk diffusion is not a reliable method due to the high rates of very major errors. E-test would be an alternative method being practical and easily evaluated, especially in routine laboratories in which the reference method could not be performed

Molecular epidemiology of quinolon resistant strains of extended spectrum beta-lactamase producing Escherichia coli

Objective: To determine the clonal relationship of ESBL-producing and quinolone resistant E. coil strains and to investigate the risk factors for infections with these microorganisms

In vitro synergism of combinations of colistin with selected antibiotics against colistin-resistant Acinetobacter baumannii.

[english] Aim: The in vitro activity of colistin in combination with sulbactam, netilmicin, and vancomycin against colistin-resistant strains was investigated. Furthermore, the clonal relationship of the strains was analyzed. Methods: Clonal relationship was investigated using rep-PCR. To screen for synergysm, the fractional inhibitory concentration index (FICI) was calculated using checkerboard assay. The killing kinetics of the combination of colistin with vancomycin was assessed using time-kill assay. Results: Three different clones were found among 10 clinical isolates of colistin-resistant strains. Thereof, 8 strains were susceptible to netilmicin. Synergistic interaction was detected in 1 strain with the combination of colistin-netilmicin, in 5 strains with colistin-sulbactam, and in 9 strains with colistin-vancomycin. None of combinations had antagonistic activity. Colistin-vancomycin combination resulted in rapid bactericidal activity. Conclusion: These results show a distinct in vitro synergism between colistin and vancomycin, which might be useful to treat infection with multiple-resistant strains, prevent emergence of resistant strains, and to lower doses for both antibiotics to be used

Comparative Evaluation of E-Test and Disk Diffusion Methods for Susceptibility Testing of Nocardia Species

WOS: 000291333900008PubMed ID: 21644070Variations in antimicrobial susceptibility among different Nocardia species limit the options for therapy. It is very difficult to perform antimicrobial susceptibility testing of these bacteria due to their slow growth rate and problems in inoculum preparation. The aim of this study was to compare E-test and disk diffusion methods for the determination of antimicrobial susceptibilities of Nocardia isolates. Since E-test is considered as 90% consistent with the gold standard microdilution method recommended by Clinical and Laboratory Standards Institute (CLSI), it was chosen for comparison with disk diffusion and in order to determine the use of disk diffusion in routine practice. A total of 21 Nocardia strains isolated from clinical specimens (12 lung, 7 brain and 2 skin/soft tissue samples) were included in the study. Six of the isolates were identified as N.asteroides, six were N.farcinica, five were N.cyriacigeorgica and four were Nocardia spp. by conventional methods. Susceptibilities of strains to ampicillin, ampicillin-sulbactam, amoxicillin-clavulanic acid, ceftazidime, sefepime, imipenem, gentamicin, erythromycin, levofloxacin, moxifloxacin, trimethoprim-sulfamethoxazole, piperacillin-tazobactam, tigecycline, and linezolid were investigated by using E-test and/or disk diffusion methods. The results were interpreted according to the CLSI breakpoints for Staphylococcus spp. All of the strains were found to be resistant to ceftazidime, piperacillin-tazobactam and ampicillin, however susceptible to levofloxacin, moxifloxacin, trimethoprim-sulfamethoxazole tigecycline, and linezolid. The concordance between the methods in terms of susceptibility testing were 100% for ampicillin, ceftazidime, imipenem, gentamicin and linezolid; 85.7% for erythromycin, 76.2% for sefepime, 73.7% for moxifloxacin, 71.4% for piperacillin-tazobactam, 70% for ampicillin-sulbactam and 46.2% for amoxicillin-clavulanic acid. In conclusion, the therapy must be planned according to the results of antimicrobial susceptibility testing. Disk diffusion is not a reliable method due to the high rates of very major errors. E-test would be an alternative method being practical and easily evaluated, especially in routine laboratories in which the reference method could not be performed

Ten-year surveillance of invasive Streptococcus pneumoniae isolates in central Turkey prior to the introduction of a conjugate vaccine

Introduction: The aim of this study was to characterize the serotypes and antimicrobial susceptibility patterns of invasive Streptococcus pneumoniae isolates in central Turkey