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Antibacterial activity of statins: a comparative study of Atorvastatin, Simvastatin, and Rosuvastatin
Background:
Statins have several effects beyond their well-known antihyperlipidemic activity, whichinclude immunomodulatory, antioxidative and anticoagulant effects. In this study, we havetested the possible antimicrobial activity of statins against a range of standard bacterial strainsand bacterial clinical isolates.
Methods:
Minimum inhibitory concentrations (MIC) values were evaluated and compared among threemembers of the statins drug (atorvastatin, simvastatin, and rosuvastatin).
Results:
It was revealed that statins are able to induce variable degrees of antibacterial activity withatorvastatin, and simvastatin being the more potent than rosuvastatin. Methicillin-sensitivestaphylococcus aureus (MSSA), methicillin-resistant staphylococcus aureus (MRSA),vancomycin-susceptible enterococci (VSE), vancomycin-resistant enterococcus (VRE),acinetobacter baumannii, staphylococcus epidermidis, and enterobacter aerogenes, weremore sensitive to both atorvastatin, and simvastatin compared to rosuvastatin. On the otherhand, escherichia coli, proteus mirabilis, and enterobacter cloacae were more sensitive toatorvastatin compared to both simvastatin and rosuvastatin. Furthermore, most clinicalisolates were less sensitive to statins compared to their corresponding standard strains.
Conclusion:
Our findings might raise the possibility of a potentially important antibacterial class effect forstatins especially, atorvastatin and simvastatin.
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Miliary tuberculosis occurred after immunosuppressive
drug in PNH patient with completely cured tuberculosis; a
case report
Paroxysmal nocturnal hemoglobinuria (PNH) is a clonal disorder that presents with hemolytic anemia, marrow failure and thrombophilia. During acute attacks, corticosteroid can alleviate the hemolytic paroxysm, but the prolonged administration induces serious toxicity including immunosupporession. So American thoracic society (ATS) for tuberculosis (TB) recommends prophylactic anti-TB medication in patients with a long-term steroid therapy. However, in the patient who was treated for active TB in the past, there are no guidelines of the test for determining patients who have latent TB infection (LTBI) and no recommendations of TB prophylaxis if there is no evidence of reactivation at present. A 40-year-old male patient presented with fever and aggravated weakness for a week. He was diagnosed with PNH a month ago and took corticosteroid for 3 weeks. In the past, he was diagnosed with pulmonary TB and completely cured after treatment. According to guideline, he was not indicated with TB prophylaxis. However, he caught miliary TB, progressed to acute respiratory distress syndrome. We experience this embarrassing case, and emphasize the need to investigate multicentral TB prevalence and to make the guidelines of anti-TB medication in subgroups of hematologic diseases including PNH.
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Isolation of antibacterial compounds from Quercus
dilatata L. through bioassay guided fractionation
Background:
Four medicinal plants (Chrozophora hierosolymitana Spreng, Chrysanthemum leucanthemumL., Ephedra gerardiana Wall. ex Stapf, and Quercus dilatata L.) used by indigenous healersto treat various infectious diseases were selected for the present study. The major objective ofthe present study was isolation and characterization of antimicrobial components from thecrude plant extracts using bioassay guided fractionation.
Methods:
Seven methanolic extracts of the four plants were screened to identify any antimicrobialagents present in them. The active crude plant extract was fractionated first by solventpartitioning and then by HPLC. Characterization of the active fractions was done by usingspectrophotometer.
Results:
All the seven methanolic extracts showed low antifungal activity, however, when theseextracts were tested for antibacterial activity, significant activity was exhibited by twoextracts. The extract of aerial parts of Q. dilatata was most active and therefore, was selectedfor further analysis. Initially fractionation was done by solvent-solvent partitioning and out ofsix partitioned fractions, ethanol fraction was selected on the basis of results of antibacterialactivity and phytochemical analysis. Further, fractionation was carried out by RP- HPLC andpurified active subfractions were characterized by comparing their absorption spectra withthat of the known natural products isolated from the plants of Quercus genus.Discussion and conclusionThe results suggest that this is the first report of the isolated antibacterial compounds fromthis genus.
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Bioassay-guided discovery of antibacterial agents: in
vitro screening of Peperomia vulcanica, Peperomia
fernandopoioana and Scleria striatinux
Background:
The global burden of bacterial infections is high and has been further aggravated byincreasing resistance to antibiotics. In the search for novel antibacterials, three medicinalplants: Peperomia vulcanica, Peperomia fernandopoioana (Piperaceae) and Scleria striatinux(Cyperaceae), were investigated for antibacterial activity and toxicity.
Methods:
Crude extracts of these plants were tested by the disc diffusion method against six bacterialtest organisms followed by bio-assay guided fractionation, isolation and testing of purecompounds. The minimum inhibitory (MIC) and minimum bactericidal (MBC)concentrations were measured by the microdilution method. The acute toxicity of the activeextracts and cytotoxicity of the active compound were performed in mice and mammaliancells, respectively.
Results:
The diameter of the zones of inhibition (DZI) of the extracts ranged from 7-13 mm onEscherichia coli and Staphylococcus aureus of which the methylene chloride:methanol [1:1]extract of Scleria striatinux recorded the highest activity (DZI = 13 mm). Twenty-nine purecompounds were screened and one, Okundoperoxide, isolated from S. striatinux, recorded aDZI ranging from 10-19 mm on S. aureus. The MICs and MBCs indicated that thePeperomias had broad-spectrum bacteriostatic activity. Toxicity tests showed thatOkundoperoxide may have a low risk of toxicity with an LC50 of 46.88 mug/mL.
Conclusions:
The antibacterial activity of these plants supports their use in traditional medicine. The purecompound, Okundoperoxide, may yield new antibacterial lead compounds followingmedicinal chemistry exploration.
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A rapid low-cost real-time PCR for the detection of
Klebsiella pneumonia carbapenemase genes
Background:
Klebsiella pneumonia carbapenemases (KPCs) are able to hydrolyze the carbapenems, whichcause many bacteria resistance to multiple classes of antibiotics, so the rapid dissemination ofKPCs is worrisome. Laboratory identification of KPCs-harboring clinical isolates would be akey to limit the spread of the bacteria. This study would evaluate a rapid low-cost real-timePCR assay to detect KPCs.
Methods:
Real-time PCR assay based on SYBR GreenIwas designed to amplify a 106 bp product of theblaKPC gene from the159 clinical Gram-negative isolates resistant to several classes of beta-lactam antibiotics through antimicrobial susceptibility testing. We confirmed the results ofreal-time PCR assay by the conventional PCR-sequencing. At the same time, KPCs of theseclinical isolates were detected by the modified Hodge test (MHT). Then we compared theresults of real-time PCR assay with those of MHT from the sensitivity and specificity.Moreover, we evaluated the sensitivity of the real-time PCR assay.
Results:
The sensitivity and specificity of the results of the real-time PCR assay compared with thoseof MHT was 29/29(100 %) and 130/130(100 %), respectively. The results of the real-timePCR and the MHT were strongly consistent (Exact Sig. (2-tailed) =1. 000; McNemar test).The real-time PCR detection limit was about 0.8 cfu using clinical isolates.
Conclusion:
The real-time PCR assay could rapidly and accurately detect KPCs -harboring strains withhigh analytical sensitivity and specificity.
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Inhibitory effect of Allium sativum and Zingiber
officinale extracts on clinically important drug
resistant pathogenic bacteria
Background:
Herbs and spices are very important and useful as therapeutic agent against manypathological infections. Increasing multidrug resistance of pathogens forces to findalternative compounds for treatment of infectious diseases.
Methods:
In the present study the antimicrobial potency of garlic and ginger has been investigatedagainst eight local clinical bacterial isolates. Three types of extracts of each garlic and gingerincluding aqueous extract, methanol extract and ethanol extract had been assayed separatelyagainst drug resistant Escherichia coli, Pseudomonas aeruginosa, Bacillus subtilis,Staphylococcus aureus, Klebsiella pneumoniae, Shigella sonnei, Staphylococcus epidermidisand Salmonella typhi. The antibacterial activity was determined by disc diffusion method.
Results:
All tested bacterial strains were most susceptible to the garlic aqueous extract and showedpoor susceptibility to the ginger aqueous extract. The (minimum inhibitory concentration)MIC of different bacterial species varied from 0.05 mg/ml to 1.0 mg/ml.
Conclusion:
In the light of several socioeconomic factors of Pakistan mainly poverty and poor hygieniccondition, present study encourages the use of spices as alternative or supplementarymedicine to reduce the burden of high cost, side effects and progressively increasing drugresistance of pathogens.
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Sensitivity pattern among bacterial isolates in neonatal septicaemia in Port Harcourt, Nigeria.
Background:
The organisms responsible for neonatal sepsis vary across geographical boundaries and with the time of illness thus periodic bacteriologic surveillance is a neccessity. The present study was therefore carried out to determine the common bacterial pathogens in Port Harcourt and their sensitivity pattern.
Methods:
Four hundred and six neonates were prospectively screened for sepsis over a 6 month period. Sensitivity of the bacterial isolates to different antibiotics was determined using Kirby-Bauer diffusion method.
Results:
Gram negative organisms predominated (75.1%) with Klebsiella pneumonia (58.2%) being the commonest. The quinolones were the most sensitive antibiotics to the commonly isolated organisms.
Conclusion:
Klebsiella pneumonia is the commonest organism responsible for neonatal sepsis in Port Harcourt. There is an overall decline in the antibiotic susceptibility to the commonly isolated bacterial pathogens.
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Successful salvage therapy with Daptomycin for osteomyelitis caused by methicillin-resistant Staphylococcus aureus in a renal transplant recipient with Fabry-Anderson disease
Daptomycin is licensed in adults for the management of Staphylococcus aureus methicillin-resistant infections, including bone and skin complicated infections. We describe for the first time its use in a renal transplant recipient for Fabry-Anderson Disease with right heel osteomyelitis. The patient was unresponsive to first-line Teicoplanin and second-line Tigecycline, whereas he was successfully treated with third-line Daptomycin monotherapy at 4 mg/Kg/qd for 4 weeks. Local debridement was performed in advance of each line of treatment.
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Antimicrobial activity of polyphenol-rich fractions from Sida alba L. (Malvaceae) against co-trimoxazol-resistant bacteria strains
Background:
The increased resistance of microorganisms to the currently used antimicrobials has lead to the evaluation of other agents that might have antimicrobial activity. Medicinal plants are sources of phytochemicals which are able to initiate different biological activities including antimicrobialsMaterials and methodsIn vitro antibacterial (MIC, MBC and time-kill studies) of polyphenol-rich fractions from Sida alba L. (Malvaceae) was assessed using ten bacteria strains (Gram-negative and Gram-positive).
Results:
All test bacteria were susceptible to the polyphenol-rich fractions. Time-kill results showed that after 5 h exposition there was no viable microorganism in the initial inoculum and the effect of polyphenol-rich fractions was faster on Enterococcus faecalis (Gram-positive bacterium) comparatively to the other bacteria strains.
Conclusion:
The data analysis indicates that the tested of polyphenol-rich fractions has significant effects when compared with the standard antibiotic. These results therefore justify the traditional use of sida alba L., alone or in combination with other herbs to treat bacterial infections.
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First Initial community-acquired meningitis due to Escherichia coli producing extended-spectrum beta-lactamase complicated with multiple aortic mycotic aneurysms
We report the first case of extended-spectrum beta-lactamase producing E. coli community-acquired meningitis complicated with multiple aortic mycotic aneurysms. Because of the acute aneurysm expansion with possible impending rupture on 2 abdominal CT scan, the patient underwent prompt vascular surgery and broad spectrum antibiotic therapy but he died of a hemorrhagic shock. Extended-spectrum beta-lactamase producing E. coli was identified from both blood and cerebrospinal fluid culture before vascular treatment. The present case report does not however change the guidelines of Gram negative bacteria meningitis in adults.
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