scholarly journals Antimicrobial activity of selected aminoglycoside and fluoroquinolone eye drops against Staphylococcus aureus isolated from the conjunctiva of a bacterial conjunctivitis patient

2021 ◽  
Vol 2 (2) ◽  
pp. 151-157
Author(s):  
Chigozie John Ekenze ◽  
Oyinyechi Lilian Umunnakwe ◽  
Timothy Olugbenga Ogundeko ◽  
Chioma Lilian Owunna ◽  
Florence Akuchi Mbatuegwu ◽  
...  

A comparative in vitro study was conducted to ascertain the efficacy of 4 selected antibiotic eye drops against Staphylococcus aureus strain isolated from the conjunctiva of a patient diagnosed of bacterial conjunctivitis, and were assayed on the basis of the zone of inhibition. One and two drops volume of the test drugs were inoculated (administered). Results for average inhibition zone for 1 and 2 drops volume was Levofloxacin (26.88 mm), Ciprofloxacin (25.0 mm), Tobramycin (12.5 mm), Gentamicin (7.5 mm) and Levofloxacin (33.12 mm), Ciprofloxacin (30.6 mm), Tobramycin (19.3 mm) and Gentamicin (17.5 mm) respectively with two drops having higher effect than one for Levofloxacin˃ Ciprofloxacin˃ Tobramycin˃ Gentamicin by way of order of susceptibility. The difference in the average zones of inhibition produced by equal volumes of gentamicin and tobramycin and that between ciprofloxacin and levofloxacin both not statistically significant (p˃0.05). Fluoroquinolones showed greater zones of inhibition than the aminoglycosides significantly with levofloxacin more efficacious than ciprofloxacin. One drop prescription is thus recommended. However, if two drops must be prescribed perhaps due to severity of symptoms as the clinician may deem necessary, the drugs should be administered in divided doses. Antimicrobial sensitivity test should be conducted in cases of ocular bacterial infections caused by Staphylococcus aureus while treatment with fluoroquinolone especially levofloxacin eye drops as the first line treatment is also suggested.

Author(s):  
Mohammed AbdulReda Yassen

Bacterial infections become a great health problems. The new antimicrobial agents are will reduce this problem. In this study, antimicrobial of activity of extract of Nigella sativa seed that used against Staphylococcus aureus isolates was evaluated. Started with an objective to appraisal the antibacterial potentials of ethanol extractofNigella sativaprepared in different concentrations (50,100, 200& 400 mg/ml) against Staphylococcus aureus and associated its activity with antibiotic concentration value Ciprofloxacin (5µg),Amoxicillin (25µg) & Penicillin (6µg) by determining the inhibition zone produced around the holes after growth on Muller-Hinton agar. This results showed activity of antibacterial of the Nigella sativa at differentconcentrationsand standard antibiotics exhibited various degrees of zones of inhibition in the culture media depending mainly upon the type of plant extract,concentration of extract in addition to the type of tested bacterial. Nearly all the Nigella sativa extracts were found to have significant activity (p<0.05) against all tested bacteria related with negative control. In the same time the current study was recorded that inhibition zones diameter against examined bacteria raised significantly difference (p<0.05) at extract concentration raised (400 mg / ml ). The MIC values ofethanolic extracts of Nigella sativaextended from 0.156 to 0.312 mg/ml against tested bacteria. Whereas the MBC values ranged 1.248 mg/ml.


2005 ◽  
Vol 62 (5) ◽  
pp. 383-387
Author(s):  
Marija Toskic-Radojicic ◽  
Zorka Nonkovic

Backgraund. Officinal basis for the antibiotic ointments according to the 4th Yugoslav Pharmacopoeia is a hydrophobic base containing only aliphatic hydrocarbons. The fact that antibiotics are predominantly not lipophylic raises the question about the suitability of that particular type of the base for the manufacturing of antibiotic ointments. Recent studies of the lipid analysis of the skin corneal layer indicated that lipids had shown the bilamellar organization in the skin intercorneal space. Such structural organization could be seen in the ambiphylic bases whose structure was based on carefully selected emulsifier couple, consisting of the lyotropic and thermotropic liquid crystals. The aim of this study was to test the velocity of antibiotics (klindamycin hydrochloride, erythromycin base and chloramphenicol) release from the hydrophobic ointment-type bases, and from ambiphylic bases of anionic and non-ionic types. Methods. Membrane-free agar diffusion test as the basic method for testing the release velocity in vitro and Staphylococcus aureus as the strain highly susceptible to the chosen antibiotics were used. All the analyzed samples were manufactured as the suspension-type ointments. Results. The highest growth inhibition zone of the Staphylococcus aureus strain for all three analyzed antibiotics was achieved from the non-ionogenic ambiphylic base; the clear growth inhibition zone area for Staphylococcus aureus strain in the preparations containing anionic ambiphylic base was smaller by 10-31.28%, and in the preparations containing aliphatic hydrocarbon-type base, the decrease was 11.46-31.28%, compared to the results achieved with the non-ionogenic ambiphylic base. Conclusion. The optimal release velocity for the analyzed antibiotics was achieved from the non-ionic ambiphylic base.


2020 ◽  
Vol 7 (Supplement_1) ◽  
pp. S622-S623
Author(s):  
Alisa W Serio ◽  
S Ken Tanaka ◽  
Kelly Wright ◽  
Lynne Garrity-Ryan

Abstract Background In animal models of Staphylococcus aureus infection, α-hemolysin has been shown to be a key virulence factor. Treatment of S. aureus with subinhibitory levels of protein synthesis inhibitors can decrease α-hemolysin expression. Omadacycline, a novel aminomethylcycline antibiotic in the tetracycline class of bacterial protein biosynthesis inhibitors, is approved in the United States for treatment of community-acquired bacterial pneumonia (CABP) and acute bacterial skin and skin structure infections (ABSSSI) in adults. This study was performed to determine the durability of inhibition and effect of subinhibitory concentrations of omadacycline on S. aureus hemolytic activity. Methods All experiments used the methicillin-sensitive S. aureus strain Wood 46 (ATCC 10832), a laboratory strain known to secrete high levels of α-hemolysin. Minimum inhibitory concentrations (MICs) of omadacycline and comparator antibiotics (tetracycline, cephalothin, clindamycin, vancomycin, linezolid) were determined. Growth of S. aureus with all antibiotics was determined and the percentage of hemolysis assayed. “Washout” experiments were performed with omadacycline only. Results S. aureus cultures treated with 1/2 or 1/4 the MIC of omadacycline for 4 hours showed hemolysis units/108 CFU of 47% and 59% of vehicle-treated cultures, respectively (Fig. 1A, 1B). In washout experiments, treatment with as little as 1/4 the MIC of omadacycline for 1 hour decreased the hemolysis units/108 CFU by 60% for 4 hours following removal of the drug (Table 1). Figure 1 Table 1 Conclusion Omadacycline inhibited S. aureus hemolytic activity in vitro at subinhibitory concentrations and inhibition was maintained for ≥ 4 hours after removal of extracellular drug (Fig. 2). The suppression of virulence factors throughout the approved omadacycline dosing interval, in addition to the in vitro potency of omadacycline, may contribute to the efficacy of omadacycline for ABSSSI and CABP due to virulent S. aureus. This finding may apply to other organisms and other virulence factors that require new protein synthesis to establish disease. Figure 2 Disclosures Alisa W. Serio, PhD, Paratek Pharmaceuticals, Inc. (Employee, Shareholder) S. Ken Tanaka, PhD, Paratek Pharmaceuticals, Inc. (Employee, Shareholder) Kelly Wright, PharmD, Paratek Pharmaceuticals, Inc. (Employee, Shareholder) Lynne Garrity-Ryan, PhD, Paratek Pharmaceuticals, Inc. (Employee, Shareholder)


2017 ◽  
Vol 83 (17) ◽  
Author(s):  
Domonique A. Carson ◽  
Herman W. Barkema ◽  
Sohail Naushad ◽  
Jeroen De Buck

ABSTRACT Non-aureus staphylococci (NAS), the bacteria most commonly isolated from the bovine udder, potentially protect the udder against infection by major mastitis pathogens due to bacteriocin production. In this study, we determined the inhibitory capability of 441 bovine NAS isolates (comprising 26 species) against bovine Staphylococcus aureus. Furthermore, inhibiting isolates were tested against a human methicillin-resistant S. aureus (MRSA) isolate using a cross-streaking method. We determined the presence of bacteriocin clusters in NAS whole genomes using genome mining tools, BLAST, and comparison of genomes of closely related inhibiting and noninhibiting isolates and determined the genetic organization of any identified bacteriocin biosynthetic gene clusters. Forty isolates from 9 species (S. capitis, S. chromogenes, S. epidermidis, S. pasteuri, S. saprophyticus, S. sciuri, S. simulans, S. warneri, and S. xylosus) inhibited growth of S. aureus in vitro, 23 isolates of which, from S. capitis, S. chromogenes, S. epidermidis, S. pasteuri, S. simulans, and S. xylosus, also inhibited MRSA. One hundred five putative bacteriocin gene clusters encompassing 6 different classes (lanthipeptides, sactipeptides, lasso peptides, class IIa, class IIc, and class IId) in 95 whole genomes from 16 species were identified. A total of 25 novel bacteriocin precursors were described. In conclusion, NAS from bovine mammary glands are a source of potential bacteriocins, with >21% being possible producers, representing potential for future characterization and prospective clinical applications. IMPORTANCE Mastitis (particularly infections caused by Staphylococcus aureus) costs Canadian dairy producers $400 million/year and is the leading cause of antibiotic use on dairy farms. With increasing antibiotic resistance and regulations regarding use, there is impetus to explore bacteriocins (bacterially produced antimicrobial peptides) for treatment and prevention of bacterial infections. We examined the ability of 441 NAS bacteria from Canadian bovine milk samples to inhibit growth of S. aureus in the laboratory. Overall, 9% inhibited growth of S. aureus and 58% of those also inhibited MRSA. In NAS whole-genome sequences, we identified >21% of NAS as having bacteriocin genes. Our study represents a foundation to further explore NAS bacteriocins for clinical use.


2017 ◽  
Vol 10 (2) ◽  
pp. 152-157 ◽  
Author(s):  
Grazielle Millo ◽  
Apa Juntavee ◽  
Ariya Ratanathongkam ◽  
Natsajee Nualkaew ◽  
Peerapattana, Jomjai ◽  
...  

ABSTRACT Aim This study evaluated the in vitro antibacterial effects of the formulated Punica granatum (PG) gel against Streptococcus mutans, Streptococcus sanguinis, and Lactobacillus casei. Materials and methods The PG extract was dissolved in water at 500 mg/mL. High performance liquid chromatography (HPLC) was used for identification and quantification of chemical marker punicalagin. Minimum bactericidal concentration (MBC) and time-kill assay (TKA) were investigated. Antibacterial activities of the formulated PG gel, 2% chlorhexidine (CHX) gel and blank gel were tested by measuring the zones of inhibition through agar well diffusion method. Results The HPLC results showed presence of punicalagin at 2023.58 ± 25.29 μg/mL in the aqueous PG extract and at 0.234% (w/w) in the formulated PG gel. The MBC for S. mutans, S. Sanguinis, and L. casei were 250, 125, and 500 mg/mL respectively. The TKA of 500 mg/mL aqueous PG extract showed total inhibition of S. mutans, S. Sanguinis, and L. casei at 6, 1, and 24 hours contact time respectively. Agar well diffusion revealed that for S. mutans, CHX gel > PG gel > blank gel; for S. sanguinis, CHX gel = PG gel > blank gel; for L. casei, CHX gel > PG gel = blank gel. Comparison of the PG gel potency showed that S. sanguinis = S. mutans > L. casei. Conclusion The PG gel equivalent to 0.234% punicalagin (w/w) inhibited S. mutans and S. sanguinis but not L. casei within 24 hours incubation period and has the potential to be used for caries prevention. How to cite this article Millo G, Juntavee A, Ratanathongkam A, Nualkaew N, Peerapattana J, Chatchiwiwattana S. Antibacterial Inhibitory Effects of Punica Granatum Gel on Cariogenic Bacteria: An in vitro Study. Int J Clin Pediatr Dent 2017;10(2):152-157.


2008 ◽  
Vol 16 (4) ◽  
pp. 275-279 ◽  
Author(s):  
Evandro Watanabe ◽  
Juliane Maria Guerreiro Tanomaru ◽  
Andresa Piacezzi Nascimento ◽  
Fumio Matoba-Júnior ◽  
Mario Tanomaru-Filho ◽  
...  

2016 ◽  
Vol 65 (10) ◽  
pp. 1171-1181 ◽  
Author(s):  
Bartłomiej Micota ◽  
Beata Sadowska ◽  
Anna Podsędek ◽  
Małgorzata Paszkiewicz ◽  
Dorota Sosnowska ◽  
...  

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