scholarly journals Comparison of a Repetitive Extragenic Palindromic Sequence-Based PCR Method and Clinical and Microbiological Methods for Determining Strain Sources in Cases of Nosocomial Acinetobacter baumannii Bacteremia

2002 ◽  
Vol 40 (12) ◽  
pp. 4571-4575 ◽  
Author(s):  
D. Martin-Lozano ◽  
J. M. Cisneros ◽  
B. Becerril ◽  
L. Cuberos ◽  
T. Prados ◽  
...  
Keyword(s):  
Acinetobacter Baumannii ◽  
Palindromic Sequence ◽  
Microbiological Methods ◽  
Pcr Method ◽  
Repetitive Extragenic Palindromic

Identification of Bacteroides forsythus in Subgingival Dental Plaque with the Aid of a Rapid PCR Method

1997 ◽  
Vol 76 (7) ◽  
pp. 1376-1380 ◽  
Author(s):  
J.H. Meurman ◽  
J. Wahlfors ◽  
A. Korhonen ◽  
P. Alakuijala ◽  
P. Väisänen ◽  
...  
Keyword(s):  
Dental Plaque ◽  
Subgingival Plaque ◽  
Chain Reaction ◽  
Rapid Pcr ◽  
Microbiological Methods ◽  
Pcr Method ◽  
Polymerase Chain ◽  
Pre Treatment ◽  
Culture Positive ◽  
Positive Results

Bacteroides forsythus has been shown to be prevalent among patients with periodontitis. Conventional microbiological methods used to identify this bacterium, however, are laborious and time-consuming and are therefore not well-suited for screening purposes. We have developed a polymerase chain-reaction (PCR) method which is rapid, specific, and simple to perform and does not require other sample pre-treatment except a brief centrifugation. This method was applied to the detection of B. forsythus in subgingival plaque of 58 periodontitis patients. When compared with the results of conventional culturing, the PCR method always confirmed the culture-positive results, while none of the PCR negative samples was shown to be culture-positive. The PCR method appeared to give more than double the number of samples positive for B. forsythus than culturing (89.7% vs. 37.9%). The analysis requires less than 4 hrs to perform, and is specific only to B. forsythus and sensitive enough to detect fewer than 5 bacteria.

scholarly journals The Frequency of Antibiotic Resistance and ESBLs Among Clinically Acinetobacter baumannii Strains Isolated from Patients in a Major Hospital in Tehran, Iran

2018 ◽  
Vol 12 (1) ◽  
pp. 254-260 ◽  
Author(s):  
Reza Ranjbar ◽  
Sajjad S. Tolon ◽  
Shahin Zayeri ◽  
Mehrdad Sami
Keyword(s):  
Antibiotic Resistance ◽  
Acinetobacter Baumannii ◽  
Bacterial Resistance ◽  
Treatment Options ◽  
Clinical Samples ◽  
Limiting Factor ◽  
Beta Lactamases ◽  
Microbiological Methods ◽  
Extended Spectrum Beta Lactamases ◽  
Amoxicillin Clavulanic Acid

Background:Bacterial resistance to antibiotics limits treatment options, increases morbidity and mortality, and raises the risk of antibiotic-associated adverse events. Antibacterial resistance emerges rapidly following an increase in the consumption of antibiotics against infectious diseases. The spread of ESBL producing strains has a limiting factor based on antibiotic function for the treatment of infections particularly caused byAcinetobacter baumannii(A. baumannii).Objective:This study was conducted to evaluate the prevalence of antimicrobial resistance and distribution ofblaTEM,blaCTX, andblaSHVgenes amongA. baumanniistrains isolated from clinical samples at a major hospital in Teheran, Iran.Methods:A. baumanniistrains were isolated and identified using standard microbiological methods. The disc diffusion and combined discs methods were used for testing antimicrobial susceptibility and to identify the strains producing Extended-Spectrum Beta-Lactamases (ESBL), respectively. DNA extraction was done by boiling method. Finally, the frequency of resistant genes includingblaTEM,blaCTX, andblaSHVin ESBL producing isolates was studied by PCR.Results:Gender distribution in this study was 53 (53%) samples for men and 47 (47%) for women. Totally, one hundredA. baumanniistrains were isolated. More than 93% of the isolates were multi drug resistant. The highest to lowest antibiotic resistance was observed against amoxicillin/clavulanic acid (98%), ceftriaxone (96%), cefotaxime (94%), and ceftazidime (93%), respectively. The frequency of positive phenotypic test of ESBL was 19% and 16% for CAZ-C and CTX-C, respectively. The frequency ofblaTEM,blaCTX, andblaSHVgenes was 52.1, 43.4, and 21.7, respectively.Conclusion:A. baumanniiisolates exhibited an extremely worrying level of antibiotic resistance, and a high percentage of the isolates showed MDR in this study. This is a serious warning because ESBLs are a major threat to the effectiveness of antibiotics that are currently available for medical uses. The frequency of genes encoded ESBL isolates ofA. baumanniimay be due to overuse and misuse of antibiotics.

scholarly journals Molecular Analysis of the Isolates of Acinetobacter baumannii isolated from Tehran Hospitals Using ERIC-PCR Method

2017 ◽  
Vol 1 (1) ◽  
pp. 12-16 ◽  
Author(s):  
Abbas Maleki ◽  
Jalil Vandyousefi ◽  
Zeinab Mirzaie ◽  
Sobhan Ghafourian ◽  
Hossein Kazemian ◽  
...  
Keyword(s):  
Acinetobacter Baumannii ◽  
Molecular Analysis ◽  
Pcr Method

scholarly journals Dissemination of Plasmid-Mediated Aminoglycoside-Modifying Enzymes Among MDR Acinetobacter baumannii Isolates from a Tertiary Care Egyptian Hospital

2020 ◽  
Vol 14 (1) ◽  
pp. 98-106
Author(s):  
Mahmoud M. Tawfick ◽  
Hamada F. Rady ◽  
Mervat I. El-Borhamy ◽  
Anwar D. Maraqa
Keyword(s):  
Acinetobacter Baumannii ◽  
Tertiary Care ◽  
Multidrug Resistant ◽  
Resistance Rate ◽  
Care Hospital ◽  
Aminoglycoside Resistance ◽  
Antimicrobial Susceptibility Pattern ◽  
Pcr Method ◽  
Resistance Rates ◽  
Encoding Genes

Background: Acinetobacter baumannii is one of the most challenging multidrug-resistant (MDR) nosocomial pathogens worldwide. Aminoglycosides are used for the treatment of A. baumannii infections, however, resistance to aminoglycosides is currently emerging, limiting therapeutic choices. Objective: In this study, the prevalence of aminoglycoside resistance and plasmid-mediated mechanisms of aminoglycoside resistance were investigated in A. baumannii clinical isolates collected from ICU patients at a tertiary care hospital in Egypt. Methods: The automated Vitek 2 system was used to identify A. baumannii species and determination of the antimicrobial susceptibility pattern. The identification of A. baumannii was confirmed by the detection of the blaOXA-51-like gene intrinsic to this species. Minimum Inhibitory Concentration (MIC) of gentamicin was determined using E-test following the CLSI breakpoints. Isolates were screened for the prevalence and diversity of the plasmid-carried aminoglycoside-modifying enzymes encoding genes aacC1, aadA1, aadB and aphA6. For genetic diversity analysis, the ERIC-PCR method was performed. Results: All A. baumannii isolates were MDR with high resistance rates to tested antimicrobials. The resistance rate to gentamicin was 92.9% with elevated MICs (≥ 32 μg/mL). The gentamicin-resistant isolates harboured one or more of the studied genes with the prevalence of aphA6 (81%). ERIC-based genotyping revealed that there was no evidence of A. baumannii clonal dissemination among isolates. Conclusion: The study concluded that MDR A. baumannii isolates were highly resistant to gentamicin. The plasmid-carried aminoglycoside-modifying enzymes encoding genes were disseminated among isolates with the AphA6 gene, which was the most prevalent one. The acquisition of more than one aminoglycoside resistance gene was associated with an elevated MIC of gentamicin. Thus, regular surveillance studies of the emerging resistance to antimicrobials and strict measures to control the dissemination of resistance determinants genes are warranted.

scholarly journals SYBR Green Real-Time PCR Method To Detect Clostridium botulinum Type A

2007 ◽  
Vol 73 (9) ◽  
pp. 2891-2896 ◽  
Author(s):  
Lucia Fenicia ◽  
Fabrizio Anniballi ◽  
Dario De Medici ◽  
Elisabetta Delibato ◽  
Paolo Aureli
Keyword(s):  
Real Time ◽  
Real Time Pcr ◽  
Clostridium Botulinum ◽  
False Negative ◽  
Type A ◽  
Sybr Green ◽  
Mouse Bioassay ◽  
Chelex 100 ◽  
Microbiological Methods ◽  
Pcr Method

ABSTRACT Botulinum toxins (BoNTs) are classically produced by Clostridium botulinum but rarely also from neurotoxigenic strains of Clostridium baratii and Clostridium butyricum. BoNT type A (BoNT/A), BoNT/B, BoNT/E, and very rarely BoNT/F are mainly responsible for human botulism. Standard microbiological methods take into consideration only the detection of C. botulinum. The presumptive identification of the toxigenic strains together with the typing of BoNT has to be performed by mouse bioassay. The development of PCR-based methods for the detection and typing of BoNT-producing clostridia would be an ideal alternative to the mouse bioassay. The objective of this study was to develop a rapid and robust real-time PCR method for detecting C. botulinum type A. Four different techniques for the extraction and purification of DNA from cultured samples were initially compared. Of the techniques used, Chelex 100, DNeasy tissue kit, InstaGene matrix DNA, and boiling, the boiling technique was significantly less efficient than the other three. These did not give statistically different results, and Chelex 100 was chosen because it was less expensive than the others. In order to eliminate any false-negative results, an internal amplification control was synthesized and included in the amplification mixture according to ISO 22174. The specificity of the method was tested against 75 strains of C. botulinum type A, 4 strains of C. botulinum type Ab, and 101 nontarget strains. The detection limit of the reaction was less than 6 × 101 copies of C. botulinum type A DNA. The robustness of the method was confirmed using naturally contaminated stool specimens to evaluate the tolerance of inhibitor substances. SYBR green real-time PCR showed very high specificity for the detection of C. botulinum types A and Ab (inclusivity and exclusivity, 100%).

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