MDR Bacterial Strains Research Articles

Prevalence and antibiotic sensitivity profiles of bacteria causing community acquired pneumonia in Rawalpindi, Pakistan

Background: Despite the availability of potent new anti-microbial agents and vaccines, Community Acquired Pneumonia (CAP) remains a common and serious problem especially for developing nations. The microbial etiological agents and their resistant patterns vary widely. Irrational and unnecessary use of antibiotics, changes in environment, changes in lifestyle and increased mobility of the people have contributed to changes in the patterns of microbial profiles and their resistant patterns in the different communities. Unfortunately, there have been very few studies done regarding etiology of CAP, prevalence of causative organisms and their resistance pattern in Pakistan. Thus it was quite crucial to detect them in our context. Methods & Materials: A descriptive cross-sectional study conducted over a period of one year (April 2016–April 2017) on 750 clinically diagnosed CAP patients visiting OPD of Holy Family Hospital, Rawalpindi. Sputum samples that met the acceptance criteria were further processed according to the standard methodology. Results: Bacterial etiologies could be identified only in 45.5% of cases of CAP. Haemophilus influenzae (36.8%), Streptococcus pneumoniae (28.5%) and Pseudomonas aeruginosa (21.6%) were the commonest bacterial etiologies, Twenty-nine percent of H. influenzae isolates were MDR. The prevalence of MDR bacteria in CAP patients was 52.44%. Among gram-negative bacterial isolates, the highest number of MDR was seen in Pseudomonas aeruginosa, followed by Klebsiella pneumoniae, E. coli and Acinetobacter spp. The prevalence of ESBL, AmpC and MBL producing gram-negative bacteria were 12.5% (more common among Klebsiella pneumoniae (18.56%), 7.9% and 5.8% (more common among Acinetobacter spp (16.32%) respectively. Conclusion: Different bacteria are responsible for CAP in our setting. MDR, ESBL, MBL and AmpC producing bacterial strains are present in our community also. Thus it has demanded to take special care during treatment of patients with community acquired infections also and also sought for other similar type of extensive studies on large number of community isolates to characterize their genetic relatedness and resistant patterns so that appropriate measures can be applied.

ANIBACTERIAL EFFICACY AND GAS CHROMATOGRAPHY-MASS SPECTROMETERY ANALYSIS OF BIOACTIVE COMPOUNDS PRESENT IN DIFFERENT EXTRACTS OF ALLIUM SATIVUM

Objective: Medicinal plants are rich libraries containing wide variety of compounds of therapeutic values. Allium sativum commonly known as garlic is a very well-known medicinal plants being used with food products. In the present study, the antibacterial activity of different extracts of A. sativum was investigated along with their phytochemical analysis by gas chromatography-mass spectrometery (GC-MS) to explore antimicrobial compounds present in extracts.Methods: The antibacterial activity of A. sativum was evaluated against 9 reference bacterial strains and 3 MDR bacterial strains including Escherichia coli MDREC1, Klebsiella pneumoniae MDRKP2, and Pseudomonas aeruginosa MDRPA3 by microbroth dilution and agar well diffusion method.Results: The results obtained from agar well diffusion assay showed the zone of inhibition from 12 to 26 mm for different extracts. The methanol and acetone extracts were found most potent against reference and MDR bacterial strains. MIC values were in the range of 1.87–7.5 mg/ml. Further, GCMS analysis confirmed the presence of 35 compounds including dodecanoic acid, hexadecanoic acid, and methyl ester in common.Conclusion: The varied antimicrobial activity of extracts was due to the presence of different concentrations of the identified compounds which can be isolated and used for the treatment of various infectious diseases caused by MDR strains of E. coli, P. aeruginosa, and K. pneumoniae.

Multidrug resistant bacteria are sensitive to Euphorbia prostrata and six others Cameroonian medicinal plants extracts

BackgroundMultidrug resistant (MDR) bacteria are responsible for therapeutic failure and there is an urgent need for novels compounds efficient on them.MethodsEleven methanol extracts from seven Cameroonian medicinal plants were tested for their antibacterial activity using broth micro-dilution method against 36 MDR bacterial strains including Escherichia coli, Enterobacter aerogenes, Enterobacter cloacae, Klebsiella pneumoniae, Providencia stuartii, Pseudomonas aeruginosa and Staphylococcus aureus.ResultsEuphorbia prostrata extract was found active against all the 36 tested bacteria including Gram-negative phenotypes over-expressing efflux pumps such as P. aeruginosa PA124, E. aerogenes CM64 and E. coli AG102. E. prostrata had minimal inhibitory concentrations values between 128 and 256 µg/mL on 55.55% of the studied microorganisms. Other plants extract displayed selective antibacterial activity.ConclusionsResults obtained in this study highlight the antibacterial potential of the tested plants and the possible use of E. prostrata to combat bacterial infections including MDR phenotypes.

Isolation and in vitro evaluation of bacteriophages against MDR-bacterial isolates from septic wound infections.

Multi-drug resistance has become a major problem for the treatment of pathogenic bacterial infections. The use of bacteriophages is an attractive approach to overcome the problem of drug resistance in several pathogens that cause fatal diseases. Our study aimed to isolate multi drug resistant bacteria from patients with septic wounds and then isolate and apply bacteriophages in vitro as alternative therapeutic agents. Pus samples were aseptically collected from Rajiv Gandhi Institute of Medical Science (RIMS), Kadapa, A.P., and samples were analyzed by gram staining, evaluating morphological characteristics, and biochemical methods. MDR-bacterial strains were collected using the Kirby-Bauer disk diffusion method against a variety of antibiotics. Bacteriophages were collected and tested in vitro for lytic activity against MDR-bacterial isolates. Analysis of the pus swab samples revealed that the most of the isolates detected had Pseudomonas aeruginosa as the predominant bacterium, followed by Staphylococcus aureus, Klebsiella pneumoniae and Escherichia coli. Our results suggested that gram-negative bacteria were more predominant than gram-positive bacteria in septic wounds; most of these isolates were resistant to ampicillin, amoxicillin, penicillin, vancomycin and tetracycline. All the gram-positive isolates (100%) were multi-drug resistant, whereas 86% of the gram-negative isolates had a drug resistant nature. Further bacteriophages isolated from sewage demonstrated perfect lytic activity against the multi-drug resistant bacteria causing septic wounds. In vitro analysis of the isolated bacteriophages demonstrated perfect lysis against the corresponding MDR-bacteria, and these isolated phages may be promising as a first choice for prophylaxis against wound sepsis, Moreover, phage therapy does not enhance multi-drug resistance in bacteria and could work simultaneously on a wide variety of MDR-bacteria when used in a bacteriophage cocktail. Hence, our results suggest that these bacteriophages could be potential therapeutic options for treating septic wounds caused by P. aeruginosa, S. aureus, K. pneumoniae and E. coli.

Synergistic efficacy of Bisbenzimidazole and Carbonyl Cyanide 3-Chlorophenylhydrazone combination against MDR bacterial strains

Activation of efflux systems and the formation of biofilm are majorly adapted by microbes to resist antimicrobial agents. PPEF (bisbenzimidazole) targeting topoisomerase IA is observed to be an effective bactericidal agent against both Gram-positive and Gram-negative bacterial strains and thus can be developed as potent broad-spectrum antibiotic against MDR strains. PPEF treatment did not cause target specific mutation instead it leads to up-regulation of efflux gene in E. coli K12 as a mechanism of resistance. Microscopy, fluorescence spectroscopy and flow cytometry result demonstrate higher accumulation of PPEF in efflux gene deleted E. coli K12 mutants, and also suggest that Carbonyl Cyanide 3-Chlorophenylhydrazone (CCCP), resist the efflux of PPEF, and thus increases efficacy of PPEF. Herein, we report, PPEF and CCCP synergistically killed the persistent bacterial cells, which are not killed by PPEF alone. The above two compounds together inhibited biofilm formation, eradicate preformed biofilms and kills the biofilm cells of P. aeruginosa. PPEF and CCCP together reduced bacterial load of E. coli ATCC25922 by 6 log10 in neutropenic thigh infection model of balb/c mice. Present study suggests that combination therapy could be a promising antimicrobial strategy to handle MDR pathogenic strains.

Antibiofilm agents against MDR bacterial strains: is bioactive glass BAG-S53P4 also effective?

The treatment of bone and joint infections is challenging due to the presence of bacterial biofilm and the increasing emergence of multiresistant strains. BAG-S53P4 is a bone substitute that is characterized by osteoconductive and antimicrobial properties. The aim of this study was to assess the effectiveness of BAG-S53P4 against biofilm produced in vitro by multiresistant bacterial strains. Multiresistant Staphylococcus epidermidis, Acinetobacter baumannii and Klebsiella pneumoniae isolated from bone and joint infections were used in this study. Titanium discs covered by bacterial biofilm were incubated with BAG-S53P4 or inert glass as a control. The amount of biofilm on each titanium disc was evaluated after 48 h of incubation by means of confocal laser scanning microscopy. Significantly lower total biomass volumes were observed for all strains after treatment with BAG-S53P4 when compared with controls. Moreover, the percentage of dead cells was significantly higher in treated samples than in controls for all the tested strains. BAG-S53P4 is able to reduce the biofilm produced by multiresistant S. epidermidis, A. baumannii and K. pneumoniae on titanium substrates in vitro, probably by interfering with cell viability. Owing to its osteoconductive, antibacterial and antibiofilm properties, the use of BAG-S53P4 may be a successful strategy for the treatment of bone and prosthetic joint infections.

Multi-Drug Resistant Bacterial Strains in Lower Respiratory Tract Infections, Antibiotic Sensitivity Patterns and Risk Factors

Isolation of multidrug resistant bacteria such as extended spectrum beta-lactamase (ESBL), metallo beta–lactamase (MBL) producing and Methicillin resistant Staphylococcus aureus (MRSA) causing lower respiratory tract infection (LRTI) is associated with various risk factors and a major challenge in treatment. So, the study determined bacterial etiology of lower respiratory tract infection and antibiotic sensitivity pattern with special reference to ESBL, MBL, and MRSA strains along with risk factors associated with such strains. A total of 120 specimens were collected from patients with lower respiratory tract infection along with clinical details. Combination disk method was done for the detection of ESBL and MBL producing isolates and oxacillin disc was used to detect MRSA. Out of 120 specimens, 87.5% was monomicrobial while 12.5% was polymicrobial infection. Pseudomonas aeruginosa (36.19%) was the predominant followed by Acinetobacter baumannii (28.57%), Klebsiella pneumoniae (20.95%), Escherichia coli (8.57%) and Staphylococcus aureus (5.72%). Total 33 (31.43%) out of 105 monomicrobial isolate were MDR. All MDR E. coli, K. pneumoniae, P. aeruginosa were ESBL producers and (6, 20%) out of total A. baumannii isolated produced MBL and was not found to produce ESBL. All MDR S. aureus isolates were found to be resistant to methicillin. Carbapenems followed by amikacin were found to be the most effective antibiotic for Gram negative bacilli causing LRTI. Vancomycin, Teicoplanin & Linezolid were found to be the most effective antibiotics for MRSA. 28 out of 33 MDR isolate possessing patients had comorbid illness. Isolation of MRSA, ESBL and MBL producing bacteria in LRTI are increasing in number. Increased prevalence of MDR bacterial strains form patients with comorbid illness is a major problem in healthcare centers. Nepal Journal of Science and Technology Vol. 13, No. 1 (2012) 157-163 DOI: http://dx.doi.org/10.3126/njst.v13i1.7454