Antibiotic Resistance Patterns and a Survey of Metallo-β-Lactamase Genes Including bla-IMP and bla-VIM Types in Acinetobacter baumannii Isolated from Hospital Patients in Tehran

Chemotherapy ◽  
2016 ◽  
Vol 61 (5) ◽  
pp. 275-280 ◽  
Author(s):  
Samira Aghamiri ◽  
Nour Amirmozafari ◽  
Jalil Fallah Mehrabadi ◽  
Babak Fouladtan ◽  
Mojtaba Hanafi Abdar
Keyword(s):  
Acinetobacter Baumannii ◽  
Antibiotic Sensitivity ◽  
Multidrug Resistant ◽  
Diffusion Method ◽  
Disk Diffusion Method ◽  
Antimicrobial Sensitivity ◽  
Hospital Patients ◽  
Resistance Patterns ◽  
Pcr Assays ◽  
Etiological Agents

Background: Metallo-β-lactamases (MBLs) producing strains of Acinetobacter baumannii are serious etiological agents of hospital infections worldwide. Among the β- lactams, carbapenems are the most effective antibiotics used against A. baumannii. However, resistance to these drugs among clinical strains of A. baumannii has been increasing in recent years. In this study, the antimicrobial sensitivity patterns of A. baumannii strains isolated from eleven different hospitals in Tehran, Iran, and the prevalence of MBL genes (bla-VIM and bla-IMP) were determined. Method: During a period of 5 months, 176 isolates of A. baumannii were collected from different clinical specimens from hospitalized patients in Tehran. All isolates were confirmed by biochemical methods. The isolates were tested for antibiotic sensitivity by the Kirby-Bauer disk diffusion method. Following minimum inhibitory concentration determination, imipenem-resistant isolates were further tested for MBL production by the double disk synergy test (DDST) method. PCR assays were performed for the detection of the MBL genes bla-IMP and bla-VIM. Results: The DDST phenotypic method indicated that among the 169 imipenem-resistant isolates, 165 strains were MBL positive. The PCR assays revealed that 63 of the overall isolates (36%) carried the bla-VIM gene and 70 strains (40%) harbored bla-IMP. Conclusions: It is obvious that nosocomial infections associated with multidrug-resistant Acinetobacter spp. are on the rise. Therefore, the determination of antibiotic sensitivity patterns and screening for MBL production among A. baumannii isolates is important for controlling clinical Acinetobacter infections.

scholarly journals Antibiotic Resistance of Uropathogens Isolated from Patients Hospitalized in District Hospital in Central Poland in 2020

Antibiotics ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 447
Author(s):  
Barbara Kot ◽  
Agata Grużewska ◽  
Piotr Szweda ◽  
Jolanta Wicha ◽  
Urszula Parulska
Keyword(s):  
Antibiotic Resistance ◽  
Multidrug Resistant ◽  
Diffusion Method ◽  
Disk Diffusion Method ◽  
Beta Lactamases ◽  
E Coli ◽  
Central Poland ◽  
Resistance Patterns ◽  
Extended Spectrum Beta Lactamases ◽  
Tract Infections

The aim of this study was to determine antibiotic resistance patterns and the prevalence of uropathogenes causing urinary tract infections (UTIs) in patients hospitalized in January–June 2020 in central Poland. Antimicrobial susceptibility testing was performed using the disk-diffusion method. Escherichia coli (52.2%), Klebsiella pneumoniae (13.7%), Enterococcus faecalis (9.3%), E. faecium (6.2%), and Proteus mirabilis (4,3%) were most commonly isolated from urine samples. E. coli was significantly more frequent in women (58.6%) (p = 0.0089) and in the age group 0–18, while K. pneumoniae was more frequent in men (24.4%) (p = 0.0119) and in individuals aged 40–60 and >60. Gram-negative species showed resistance to ampicillin. K. pneumoniae were resistant to amoxicillin plus clavulanic acid (75.0%), piperacillin plus tazobactam (76.2%), cefotaxime (76.2%), cefuroxime (81.0%), ciprofloxacin (81.0%), and trimethoprim plus sulphamethoxazole (81.0%). Carbapenems were effective against all E. coli and P. mirabilis. Some K. pneumoniae (13.6%) produced metallo-β-lactamases (MBLs). E. coli (22.6%), K. pneumoniae (81.8%), and all E. faecium were multidrug-resistant (MDR). Some E. coli (26.2%), K. pneumoniae (63.6%), and P. mirabilis (14.3%) isolates produced extended-spectrum beta-lactamases (ESBL). Vancomycin-resistant E. faecium was also found. This study showed that the possibilities of UTIs therapy using available antibiotics become limited due to the increasing number of antibiotic-resistant uropathogens.

scholarly journals Sensitivity of Acinetobacter baumannii and Pseudomonas aeruginosa Microorganisms to Colistin Antibiotic by MIC (E-test) in Patients Admitted to the Intensive Care Unit of Firoozgar Hospital

2020 ◽  
Author(s):  
Mahin Jamshidi Makiani ◽  
Maryam Farasatinasab ◽  
Sam Bemani ◽  
Hoda Namdari Moghadam ◽  
Fatemeh Sheibani ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Acinetobacter Baumannii ◽  
Antibiotic Sensitivity ◽  
Cross Sectional Study ◽  
Diffusion Method ◽  
Disk Diffusion Method ◽  
Cross Sectional ◽  
Hospitalization Period ◽  
The Mean ◽  
Mean Time

Background: Nosocomial infections are associated with increased morbidity, mortality, and medical burdens. Pseudomonas aeruginosa and Acinetobacter baumannii are not-fermentative gram-negative bacteria that considered as the most important nosocomial infection. In the current study, we have aimed to evaluate the sensitivity of Acinetobacter baumannii and Pseudomonas aeruginosa microorganisms to the colistin antibiotic. Methods: In this descriptive cross-sectional study, patients admitted to the ICU ward of Firoozgar Hospital from July 2018 to March 2019 were evaluated, and 169 Patients infected with Acinetobacter baumannii, and Pseudomonas aeruginosa were included. Acinetobacter baumannii and Pseudomonas aeruginosa were isolated, and antibiotic sensitivity was determined by the disk diffusion method according to Clinical & Laboratory Standards Institute (CLSI) criteria. E test was also used to determine MIC-50 and MIC-90 of colistin. Results: Acinetobacter baumannii was around 8 times more frequent than Pseudomonas aeruginosa. Colistin resistance was detected in only 4(2.4%). The mean age of patients infected by Acinetobacter baumannii was significantly higher than those infected with Pseudomonas aeruginosa. Moreover, the mean time of the hospitalization period did not show any significant differences in the different groups. Conclusion: Our findings indicated that the majority of isolated Pseudomonas aeruginosa and Acinetobacter baumannii were sensitive to Colistin. Therefore, it could be effectively used for patients with a confirmed diagnosis of Pseudomonas aeruginosa and Acinetobacter baumannii.

scholarly journals Molecular Detection of blaOXA-type Carbapenemase Genes and Antimicrobial Resistance Patterns among Clinical Isolates of Acinetobacter baumannii

2021 ◽  
Author(s):  
Maghsoud Kafshnouchi ◽  
Marzieh Safari ◽  
Amir Khodavirdipour ◽  
Abbas Bahador ◽  
Seyed Hamid Hashemi ◽  
...  
Keyword(s):  
Antimicrobial Resistance ◽  
Acinetobacter Baumannii ◽  
Dominant Gene ◽  
Diffusion Method ◽  
Phylogenetic Tree Analysis ◽  
Disk Diffusion Method ◽  
Treatment Regimens ◽  
Class D ◽  
Resistance Patterns ◽  
New Treatment

Abstract Acinetobacter baumannii is a bacterium found in most places, especially in clinics and hospitals, and an important agent of nosocomial infections. The presence of class D enzymes such as OXA-type carbapenemases in A. baumannii is proven to have a key function in resistance to carbapenem. The aim of the current study is to determine the blaOXA-type carbapenemase genes and antimicrobial resistance among clinically isolated samples of A. baumannii. We assessed 100 clinically isolated specimens of A. baumannii from patients in intensive care units of educational hospitals of Hamadan, West of Iran. The A. baumannii isolates' susceptibility to antibiotics was performed employing disk diffusion method. Multiplex polymerase chain reaction was used to identify the blaOXA-24-like , blaOXA-23-like , blaOXA-58-like , and blaOXA-51-like genes. The blaOXA-23-like , blaOXA-24-like , and blaOXA-58-like genes' prevalence were found to be 84, 58, and 3%, respectively. The highest coexistence of the genes was for blaOXA-51/23 (84%) followed by blaOXA-51/24-like (58%). The blaOXA-51/23- like pattern of genes is a sort of dominant gene in resistance in A. baumannii from Hamadan hospitals. The highest resistance to piperacillin (83%) and ciprofloxacin (81%) has been observed in positive isolates of blaOXA-23-like . The A. baumannii isolates with blaOXA-58-like genes did not show much resistance to antibiotics. Based on the results of the phylogenetic tree analysis, all isolates have shown a high degree of similarity. This study showed the high frequency of OXA-type carbapenemase genes among A. baumannii isolates from Hamadan hospitals, Iran. Thus, applying an appropriate strategy to limit the spreading of these strains and also performing new treatment regimens are necessary.

scholarly journals Overexpression of blaOXA-58 Gene Driven by ISAba3 is Associated with Imipenem Resistance in a Clinical Acinetobacter baumannii Isolate from Vietnam

2020 ◽  
Author(s):  
Anh T. Nguyen ◽  
Son C. Pham ◽  
Anh K. Ly ◽  
Chau V.V. Nguyen ◽  
Thanh T. Vu ◽  
...  
Keyword(s):  
Gene Expression ◽  
Acinetobacter Baumannii ◽  
Mrna Level ◽  
Pcr Amplification ◽  
Multidrug Resistant ◽  
Resistant Isolate ◽  
Diffusion Method ◽  
Disk Diffusion Method ◽  
Imipenem Resistance ◽  
Very High

AbstractThe aim of this study was to investigate genetic structures and expression of blaOXA-58 gene in five Acinetobacter baumannii clinical isolates recovered from two hospitals in southern Vietnam during 2012-2014. A. baumannii isolates were identified by automated microbiology systems and confirmed by PCR. All isolates were characterized as multidrug resistant by antimicrobials testing using the disk diffusion method. Four imipenem susceptible and one non-susceptible isolates (MIC > 32 μg.ml−1) were identified by E-test. PCR amplification of blaOXA-58 gene upstream and downstream sequences revealed the presence of ISAba3 at both locations in one multidrug resistant isolate. Semi quantitation of blaOXA-51 and blaOXA-58 gene expression was performed by the 2−ΔΔCt method. The blaOXA-51 gene expression of five isolates showed little difference but the isolate bearing ISAba3-blaOXA-58-ISAba3 exhibited significant higher blaOXA-58 mRNA level. Higher β-lactamases activity in periplasmic than cytoplasmic fraction was found in most isolates. The isolate overexpressing blaOXA-58 gene possessed very high periplasmic enzyme activity. In conclusion, the A. baumannii isolate bearing ISAba3-blaOXA-58 gene exhibited high resistance to imipenem, corresponding to an overexpression of blaOXA-58 gene and very high periplasmic β-lactamases activity.

scholarly journals Overexpression of blaOXA-58 Gene Driven by ISAba3 Is Associated with Imipenem Resistance in a Clinical Acinetobacter baumannii Isolate from Vietnam

2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Anh T. Nguyen ◽  
Son C. Pham ◽  
Anh K. Ly ◽  
Chau V. V. Nguyen ◽  
Thanh T. Vu ◽  
...  
Keyword(s):  
Gene Expression ◽  
Acinetobacter Baumannii ◽  
Mrna Level ◽  
Pcr Amplification ◽  
Multidrug Resistant ◽  
Resistant Isolate ◽  
Diffusion Method ◽  
Disk Diffusion Method ◽  
Imipenem Resistance ◽  
Very High

The aim of this study was to investigate genetic structures and expression of blaOXA-58 gene in five Acinetobacter baumannii clinical isolates recovered from two hospitals in southern Vietnam during 2012-2014. A. baumannii isolates were identified by automated microbiology systems and confirmed by PCR. All isolates were characterized as multidrug resistant by antimicrobial testing using the disk diffusion method. Four imipenem susceptible and one nonsusceptible isolates (MIC>32 μg·ml-1) were identified by E-test. PCR amplification of blaOXA-58 gene upstream and downstream sequences revealed the presence of ISAba3 at both locations in one multidrug-resistant isolate. Semiquantitation of blaOXA-51 and blaOXA-58 gene expression was performed by the 2-ΔΔCt method. The blaOXA-51 gene expression of five isolates showed little difference, but the isolate bearing ISAba3-blaOXA-58-ISAba3 exhibited significantly higher blaOXA-58 mRNA level. Higher β-lactamases activity in periplasmic than cytoplasmic fraction was found in most isolates. The isolate overexpressing blaOXA-58 gene possessed very high periplasmic enzyme activity. In conclusion, the A. baumannii isolate bearing ISAba3-blaOXA-58 gene exhibited high resistance to imipenem, corresponding to an overexpression of blaOXA-58 gene and very high periplasmic β-lactamase activity.

scholarly journals Colistin and Carbapenem-Resistant Acinetobacter baumannii Aci46 in Thailand: Genome Analysis and Antibiotic Resistance Profiling

Antibiotics ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 1054
Author(s):  
Nalumon Thadtapong ◽  
Soraya Chaturongakul ◽  
Sunhapas Soodvilai ◽  
Padungsri Dubbs
Keyword(s):  
Antibiotic Resistance ◽  
Acinetobacter Baumannii ◽  
Antibiotic Resistance Genes ◽  
Carbapenem Resistance ◽  
Multidrug Resistant ◽  
Diffusion Method ◽  
Whole Genome ◽  
Disk Diffusion Method ◽  
Genome Data ◽  
Carbapenem Resistant

Resistance to the last-line antibiotics against invasive Gram-negative bacterial infection is a rising concern in public health. Multidrug resistant (MDR) Acinetobacter baumannii Aci46 can resist colistin and carbapenems with a minimum inhibitory concentration of 512 µg/mL as determined by microdilution method and shows no zone of inhibition by disk diffusion method. These phenotypic characteristics prompted us to further investigate the genotypic characteristics of Aci46. Next generation sequencing was applied in this study to obtain whole genome data. We determined that Aci46 belongs to Pasture ST2 and is phylogenetically clustered with international clone (IC) II as the predominant strain in Thailand. Interestingly, Aci46 is identical to Oxford ST1962 that previously has never been isolated in Thailand. Two plasmids were identified (pAci46a and pAci46b), neither of which harbors any antibiotic resistance genes but pAci46a carries a conjugational system (type 4 secretion system or T4SS). Comparative genomics with other polymyxin and carbapenem-resistant A. baumannii strains (AC30 and R14) identified shared features such as CzcCBA, encoding a cobalt/zinc/cadmium efflux RND transporter, as well as a drug transporter with a possible role in colistin and/or carbapenem resistance in A. baumannii. Single nucleotide polymorphism (SNP) analyses against MDR ACICU strain showed three novel mutations i.e., Glu229Asp, Pro200Leu, and Ala138Thr, in the polymyxin resistance component, PmrB. Overall, this study focused on Aci46 whole genome data analysis, its correlation with antibiotic resistance phenotypes, and the presence of potential virulence associated factors.

scholarly journals The frequency of virulent genes and antimicrobial resistance patterns of diarrheagenic Escherichia coli isolated from stools of children presenting with diarrhea in a tertiary hospital in Abakaliki, Nigeria

2020 ◽  
Vol 6 (2) ◽  
pp. 147-152
Author(s):  
Ebuka Elijah David ◽  
Muhammad Arfat Yameen ◽  
Ikechuku Okorie Igwenyi ◽  
Arthur Chinedu Okafor ◽  
Uket Nta Obeten ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Tertiary Care ◽  
Tertiary Hospital ◽  
Diffusion Method ◽  
Disk Diffusion Method ◽  
E Coli ◽  
Diarrheagenic Escherichia Coli ◽  
Resistance Patterns ◽  
Etiological Agents ◽  
Antibiotic Resistance Patterns

Aim: This study was aimed to determine the virulent genes and antibiotic resistance patterns among circulating diarrheagenic Escherichia coli (DEC) pathotypes in a tertiary care health center in east of Nigeria. Materials and Methods: Diarrheal stool samples were obtained from 80 children under 5 years and E. coli was isolated and identified using standard biochemical and molecular methods. Multiplex polymerase chain reaction (PCR) was used to detect eight virulent genes of DEC. Disk diffusion method was used to determine the antibiotic susceptibility of DEC. Results: DEC infection was observed in 54 (68%) children among which ial gene for enteroinvasive E. coli (EIEC) (40% [n=22]) was commonly detected followed by eltA/eltB for enterotoxigenic E. coli (ETEC) (30% [n=16]), pCVD for enteroaggregative E. coli (EAEC) (20% [n=11]), and eaeA/bfpA for typical enteropathogenic E. coli (EPEC) (10% [n=5]). The DEC isolates phenotypically exhibited resistance for ampicillin (AMP) (44 [81%]), followed by ciprofloxacin (CIP)/ levofloxacin (LEV) (28 [52%]), cefoxitin (FOX) (11 [20%]), and amoxicillin-clavulanic acid (AMC) (6 [11%]). About 60% isolates of stable toxins-ETEC were resistant to AMC, CIP, and LEV while all the labile toxin-ETEC exhibited resistance to AMP. About 60% (n=6) resistance were seen in EAEC against ampicillin, AMC, FOX, CIP, and LEV. In EIEC, all the isolates (n=22) were resistant to AMP while 50% (n=11) were resistant to both CIP and LEV. All EPEC (n=5) were resistant to AMP, FOX, CIP, and LEV. Conclusion: High frequency of virulent ial and eltA/eltB genes for EIEC and ETEC, respectively, suggests that they are the primary etiological agents of diarrhea in children among DEC pathotypes. Resistance of DEC to more than two classes of antibiotics indicate possible emergence of multidrug resistance.

Antibiotic Resistance Patterns and Molecular Typing of Acinetobacter Baumannii Strains Isolated from Burn Patients in Iran

2018 ◽  
Author(s):  
Fahimeh Nourbakhsh ◽  
Elaheh Tajbakhsh ◽  
Dana Daneshmand ◽  
Samaneh Borooni ◽  
Vajiheh Nourbakhsh
Keyword(s):  
Antibiotic Resistance ◽  
Acinetobacter Baumannii ◽  
Molecular Typing ◽  
Multidrug Resistant ◽  
Diffusion Method ◽  
Resistance Pattern ◽  
Burn Patients ◽  
Disk Diffusion Method ◽  
Burn Center ◽  
Antibiotic Resistance Pattern

Background and Aims: Acinetobacter baumannii is an important multidrug-resistant opportunistic pathogen frequently causing various nosocomial infections and is a serious threat to burn patients. These infections are usually caused by the outbreak strains. The aim of this study was to show antibiotic resistance pattern and molecular typing of A.baumannii genes isolates collected from burn patients and also distribution of different types of burn patients. Materials and Methods: In this study, 307 different strains were detected. Totally 100 A.baumannii strain was selected in burn center of Isfahan hospital. Antibiotic resistance pattern was determined by disk diffusion method (Kirby Bauer). The presence of genes coding in antibiotic resistance were analyzed by using M-PCR method. The standard strains of Escherichia coli ATCC 25922 and A. baumannii ATCC 19606 were used as negative and positive controls. Results: The antibiotic resistance pattern for A.baumannii showed high resistance for ciprofloxacin, ceftazidime, and tetracycline with frequency of 82.5%, 75.3%, 72%, respectively. Moreover, the most sensitive antibiotics were chloramphenicol, and nitrofurantoin with the resistance frequency of 3.9% and 2.8%. CITM (91.1%) was the highest detected gene. Conclusions: High prevalence of antibiotic resistance pattern among A.baumannii isolated from burn center hospitals indicates the important role of multidrug resistant isolates.

scholarly journals Antibiotic Resistance Pattern and Evaluation of Metallo-Beta Lactamase Genes Including bla-IMP and bla-VIM Types in Pseudomonas aeruginosa Isolated from Patients in Tehran Hospitals

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Samira Aghamiri ◽  
Nour Amirmozafari ◽  
Jalil Fallah Mehrabadi ◽  
Babak Fouladtan ◽  
Hossein Samadi Kafil
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Antibiotic Resistance ◽  
Antibiotic Sensitivity ◽  
Diffusion Method ◽  
Resistance Pattern ◽  
Beta Lactamase ◽  
Disk Diffusion Method ◽  
Antimicrobial Sensitivity ◽  
Group B

Beta-lactamase producing strains of Pseudomonas aeruginosa are important etiological agents of hospital infections. Carbapenems are among the most effective antibiotics used against Pseudomonas infections, but they can be rendered infective by group B β-lactamase, commonly called metallo-beta lactamase. In this study, the antimicrobial sensitivity patterns of P. aeruginosa strains isolated from 9 different hospitals in Tehran, Iran, as well as the prevalence of MBLs genes (bla-VIM and bla-IMP) were determined. A total of 212 strains of P. aeruginosa recovered from patients in hospitals in Tehran were confirmed by both biochemical methods and PCR. Their antimicrobial sensitivity patterns were determined by Kirby-Bauer disk diffusion method. Following MIC determination, imipenem resistant strains were selected by DDST method which was followed by PCR tests for determination of MBLs genes: bla-IMP and bla-VIM. The results indicated that, in the DDST phenotypic method, among the 100 imipenem resistant isolates, 75 strains were MBLs positive. The PCR test indicated that 70 strains (33%) carried bla-VIM gene and 20 strains (9%) harbored bla-IMP. The results indicated that the extent of antibiotic resistance among Pseudomonas aeruginosa is on the rise. This may be due to production of MBLs enzymes. Therefore, determination of antibiotic sensitivity patterns and MBLs production by these bacteria, can be important in control of clinical Pseudomonas infection.

Prevalence of multi-drug resistant Acinetobacter baumannii (MDRAB) in Amman Jordan during 2018

2019 ◽  
Vol 19 ◽  
Author(s):  
Layla El-khatib ◽  
Saed Al-dalain ◽  
Rama Al-Matarneh ◽  
Sara Al-Bustanji ◽  
Marwa Al-Dmour ◽  
...  
Keyword(s):  
Acinetobacter Baumannii ◽  
Opportunistic Pathogen ◽  
Multidrug Resistant ◽  
Diffusion Method ◽  
Sensitivity Testing ◽  
Group Iii ◽  
Antimicrobial Sensitivity ◽  
Group I ◽  
Central Jordan ◽  
Private Laboratory

Purpose: Acinetobacter baumannii is as an opportunistic pathogen, and is among the most problematic nosocomial infections as well as community acquired infections. This retrospective study was conducted as an attempt to determine the prevalence of multidrug-resistant A. baumannii (MDRAB) isolates from north and central Jordan area during 2018. Methods: Patients records provided by an accredited central private laboratory located in Amman, were inspected for A. baumannii isolates identified during this period. The isolates were identified to the species level using API-10S system and the antimicrobial sensitivity testing was determined using Kirby–Bauer disc diffusion method. Results: A total of 43 unduplicated isolates were obtained and classified according to clinical sampling source into: Group I (blood), Group II (urine) and Group III (wound, pus, sputum, bed-sore and others). Total MDRAB recorded were 32 isolates (74.4 %). Resistance to imipenem were 36% and 94% among groups II and III respectively, and resistance to meropenem were 60% and 88% among the same groups respectively. Conclusion: Antimicrobial stewardship programs at a national scale are needed to calculate the actual proportion of MDRAB in the country and to combat its increasing emergence and decrease the magnitude of antibiotic resistance.

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