Multiple Drug Resistant Acinetobacter Research Articles

Molecular Characterization of Class A-ESBLs, Class B-MBLs, Class C-AmpC, and Class D-OXA Carbapenemases in MDR Acinetobacter baumannii Clinical Isolates in a Tertiary Care Hospital, West Bengal, India.

Background Acinetobacter calcoaceticus baumannii (ACB) complex has become a major concern nowadays because of its increasing involvement in several severe infections associated with catheter-related bloodstream and urinary tract infections, ventilator-associated pneumonia, cerebrospinal shunt-related meningitis, and wound infections. Multiple drug-resistant (MDR) ACB cases have been described with an increasing trend where at least it is resistant to a minimum of three antimicrobial groups. The mortality rate associated with A. baumannii is significantly higher than all Acinetobacterspp. isolates with the most prevalence seen in India and Thailand. The rapid spread of high resistance to most potent antimicrobial drugs is due to its ability to incorporate resistance determinants despite multifactorial reasons such as alteration in permeability of cell membrane by either losing expression of outer membrane porins or excess production of efflux pumps. This study aims to characterize resistance determinants responsible for MDR at the genetic level and emphasizes the use of genotyping in routine diagnosis as genotype analysis is reliable and valid. Methodology A total of 289 ACB complex clinical isolates were included in this study. The study for species-level identification of A. baumannii was conducted at the Department of Microbiology, IQ City Medical College Hospital, Durgapur, West Bengal. In addition, the detection of encoded genes associated with class A-extended spectrum beta-lactamases (i.e., CTX-M, KPC, SHV, and TEM genes), class B-metallo-β-lactamases (i.e., IMP, NDM, and VIM genes), Class C-AmpC cephalosporinase, and classD-OXA carbapenemases (i.e., blaOXA-10/11, blaOXA-24, blaOXA-48, blaOXA-58, blaOXA-143, and blaOXA-235was done using real-time polymerase chain reaction. Results All 289 non-repetitive ACB complex clinical isolates were confirmed as A. baumannii, of which 277 (96%) isolates were MDR. There were no findings of blaCTX-M, blaKPC, blaSHV, blaTEM, blaIMP, blaVIM, blaAmpC, blaOXA-10/11, blaOXA-24, blaOXA-48, blaOXA-58, blaOXA-143, and blaOXA-235 genes in our study. However, there were four (1.44%) positive findings of the blaNDM gene. All MDR isolates (n = 277) were positive for the blaOXA-51 gene. In addition, blaOXA-23 was positive in 269 (97.12%) isolates. Conclusions The oxacillinase production corresponding to blaOXA-23 and blaOXA-51 were the most prevalent antibiotic resistance determinants among MDR A. baumanniiin our study. Four (1.44%) isolates had the multiple genes blaOXA-51, blaOXA-23, and blaNDM that shows the coexistence of diverse genetic elements involved in MDR A. baumannii, resulting in total resistance except for a few potent drugs such as colistin and tigecycline. Genotyping is helpful in determining the contribution of the isolates in understanding their association with encoded genes, which, in turn, helps in designing effective surveillance and control strategies in the management of such MDR isolates.

Bacteria from bovine clinical mastitis showed multiple drug resistance.

Mastitis, which often manifests as udder infection in dairy animals, is of great concern as it affects public health and results in heavy economic losses to the dairy industry. A hospital-based cross-sectional study was conducted to determine the cultivable bacterial species associated with bovine clinical mastitis and their resistance patterns towards different antimicrobials. The milk samples from cows suffering from clinical mastitis during monsoon season were investigated. The prevalence of clinical mastitis was significantly high in Holstein-Friesian crossbred cows, followed by in Jersey crossbred, Red Kandhari and Deoni. Significantly high prevalence was observed during 4th to 6th months of lactation. A total of 110 bacterial isolates belonging to 14 different genera were isolated and identified. Aminoglycosides and quinolones were found to be the most effective antibiotics. Vancomycin resistant penicillinase producing Gram positive bacteria were demonstrated. Gram negative bacteria resistant to extended spectrum β lactamases, cephalosporins, tetracyclines, vancomycin and chloramphenicol as well as vancomycin resistant enterococci, multiple drug resistant (MDR) gram negative rods, MDR Pseudomonas and MDR Acinetobacter were found. Widespread resistance of Streptococcus uberis towards cephalosporins was documented. Variable MDR patterns were recorded within a single species. MDR transfer from non-pathogens to emerging foodborne and established mastitis pathogens could be a potential problem to the dairy industry as well as to public health.

A study on the actual conditions associated with the presence of Acinetobacter sp. in a hospital waiting room

In recent years, nosocomial infection, including that by multiple-drug-resistant Acinetobacter (MDRA), has become an increasing concern in Japan. Typically, Acinetobacter inhabits soil and river water and is usually harmless to humans. However, bacteria of this genus can become pathogens in inpatients with weakened immune systems, resulting in opportunistic infection. Currently, hospital infection by MDRA is spreading not only in Japan, but also worldwide. This is a very serious problem, and little is known about effective countermeasures. The present study sought to examine the microbiome status in a hospital visitor waiting room as a first step in establishing countermeasures for use against Acinetobacter. Specifically, we performed a so-called metagenomic analysis to directly analyze DNA collected from the environment, without an intervening cultivation step. Indoor airborne bacteria and surface bacteria were sampled and analyzed. The results show that in a visitor waiting room, the top-ten most-abundant genera included (in decreasing order) Acinetobacter, Streptococcus, Prevotella, Pseudomonas, Bifidobacterium, Fusobacterium, Neisseia, Porphyromonas, Leptotrichia, and Haemophilus. Thus, Acinetobacter constituted the mostdetected genus and was present in all collected samples. Furthermore, we assessed the bactericidal effect of ultraviolet C (UVC) against Acinetobacter sp. 7206, a hospital isolate. A UVC dose of 4.0 sec•mW/cm2 was required to kill the 99.9% Acinetobacter sp. 7206 on solid culture medium.

Comparison of three selective agar media for the detection multiple drug resistant Acinetobacter (MDRA)

Comparison of three selective agar media for the detection multiple drug resistant Acinetobacter (MDRA)

Clinical Course and Computed Tomography Abnormalities Associated without and with Concomitant Infection in Patients with Pandemic Influenza A (H1N1) 2009 Virus Infection

The goal was to evaluate the imaging findings in patients infected primarily with the pandemic influenza A (H1N1) 2009 virus and secondarily with a bacterium.Between October 2009 and March 2010, thirteen patients were included in this study. Five patients had H1N1 pneumonia without evidence of co-infection and their CT images showed diffuse or patchy areas of ground glass opacities and/or consolidations, lower lung zone predominant, without cyst/cavity lesion or newly developing pleural effusion. Another eight patients had H1N1 pneumonia with co-infections. The following organisms were identified: Oxacillin-resistant Staphylococcus aureus (2), Pneumocystis jiroveci (1), Haemophilus parainfluenzae (3), Klebsiella pneumoniae (1), Streptococcus pneumoniae (2), and multiple-drug resistant Acinetobacter baumannii (1), Their CT scans showed diffuse or patchy areas of ground-glass attenuation mixed with consolidation but also revealed cyst/cavity lesions (3), centrilobular nodules (3), tree-in-bud opacity (4), mediastinal lymphadenopathy (6), and pleural effusion (4), These CT changes are definitely different from H1N1 monoinfection. The secondary infectious process may cause additional CT abnormalities.The possibility of H1N1 pneumonia with co-infections should be considered if there are CT findings other than pure H1N1 pneumonia.

Antimicrobial susceptibility, plasmid profiles, and RAPD-PCR typing of Acinetobacter bacteria

Abstract Background: Multiple-drug resistant Acinetobacter have widely spread in the last decades imposing a serious nosocomial source of infection. Nevertheless, little knowledge was gaimed on tracing the development of antibiotic resistance in Acinetobacter species. Objectives: Explore Acinetobacter spp. via antimicrobial susceptibility, plasmid profiles, and random amplified polymorphism DNA polymerase chain reaction (RAPD-PCR) typing. Methods: One hundred twelve Acinetobacter isolates (including 66 A. baumannii and 46 non-Acinetobacter baumannii strains) were obtained from three university hospitals. The source of infection of these isolates included blood, urine, wound, and respiratory tract. Their susceptibilities to 17 antibiotics were tested and then all Acinetobacter isolates were typed by plasmid analysis and RAPD-PCR method. Results: A. baumannii isolates revealed nine different patterns of antibiotic resistance. Of those, non- A. baumannii, were associated with plasmid and RAPD-PCR typings (p <0.05). A. baumannii was more resistant to multiple antibiotics than non-A. baumannii (p <0.05). Seven different plasmid profiles were observed among 112 Acinetobacter isolates. Plasmids were found in 107 (95.5%) of the 112 isolates. Unlike in RAPD-PCR typing, there was no difference between the type of Acinetobacter, A. or non-A. baumannii strains and plasmid profiles (p >0.05). By RAPD-PCR, six profiles were found for each A. and non-A. baumannii strains. The pattern 6 was the most common pattern among the isolates. Both plasmid and RAPD-PCR typing showed no association between plasmid profiling and site of infection (p >0.05). Conclusion: There is a wide spread of multi-drug resistant Acinetobacter spp., particularly A. baumannii, in the Middle East region that can be traced efficiently by plasmid and genotyping typing of Acinetobacter. More care should be taken for tracing the development of antimicrobial resistance of Acinetobacter using precise molecular typing techniques.

Effects of Aerosol Colistin Treatment of Pneumonia Caused by Multi-drug Resistant Acinetobacter baumannii

Background: Acinetobacter infections are difficult to treat as they often exhibit multiple resistance to the antibiotics that are currently available for the treatment of pneumonia. Colistin is active against gram-negative bacteria, including the multiple drug resistant (MDR) Acinetobacter species. However, intravenous administration of colistin was abandoned because of its nephrotoxicity and neurotoxicity. The aims of this study were to examine the efficacy and safety of colistin administered by aerosol in the treatment of pneumonia caused by MDR Acinetobacter baumannii. Methods: We retrospectively reviewed the medical records of patients admitted to the intensive care unit (ICU) from Dec. 2006 to Aug. 2007 who had been diagnosed as suffering from pneumonia due to MDR Acinetobacter baumannii and had been treated with nebulized colistin. Results: 31 patients received aerosolized colistin. The average duration of the treatment was days and the daily dose of ranged from 225 mg to 300 mg. All patients received concomitant intravenous antimicrobial agents. The average length of the stay in the ICU was days and in the hospital days. The overall microbiological eradication was observed in 25 patients (80.6%). 14 of these (56%) were cured, and 11 (44%) were infected with other microorganisms. The overall crude mortality of the ICU was 48%. Nephrotoxicity and significant bronchial constriction did not occur in any patient during neublized colistin treatment. Conclusion: Nebulized colistin may be a safe and effective option in the treatment of pneumonia due to MDR Acinetobacter baumannii. Its role in therapy warrants further investigation in comparative studies.