STUDIES ON SOME BACTERIAL DISEASES IN OREOCHROMIS NILOTICUS WITH SPECIAL REFERENCES TO TREATMENT

he present research carried out to study the common bacterial infections in Oreochromis niloticus (Nile tilapia) in Manzala area at Dakahlia governorate and possible antimicrobial agents used for treatment. A total number of 400 fish were randomly collected from Manzala private farms at Dakahlia governorate and subjected to the clinical, bacteriological and histopathological examination. The highest prevalence of bacterial isolates during the whole period of examination of naturally infected O.niloticus was recorded for A.hydrophila (22.66%), followed by V.alginolyticus (19.01%), V.parahemolyticus (13.80%), Streptococcus spp. (12.24%), A.caviae (11.72%), V.cholera (10.16%), A.salmonicida (7.55%), while the lowest prevalence was recorded for Klebsiella oxytoca (2.86%). The seasonal highest total prevalence of bacterial isolates from examined naturally infected O. niloticus was recorded in spring (30.21%), followed by autumn (28.39%), then summer (22.40%) and the lowest prevalence was recorded in winter (19.01%). Histopathological findings of the tissue samples which collected from different organs of naturally infected O.niloticus revealed that spleen show marked hemosiderosis and sever hemorrhage, gills showsever congestion of lamellar capillaries with marked aneurysm, necrosis and hemorrhage of lamellar epithelium and liver show sever hydropic degeneration and necrosis of hepatocytes, Ciprofloxacin was the most effective antibiotic against all isolated bacterial strains

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Silver (I) N-Heterocyclic Carbene Complexes: A Winning and Broad Spectrum of Antimicrobial Properties

International Journal of Molecular Sciences ◽

10.3390/ijms22052497 ◽

2021 ◽

Vol 22 (5) ◽

pp. 2497

Author(s):

Filippo Prencipe ◽

Anna Zanfardino ◽

Michela Di Napoli ◽

Filomena Rossi ◽

Stefano D’Errico ◽

...

Keyword(s):

Bacterial Infections ◽

Antimicrobial Agents ◽

Antimicrobial Properties ◽

Resistance Mechanisms ◽

Heterocyclic Carbenes ◽

Significant Activity ◽

Bacterial Strains ◽

Development Of Resistance ◽

Starting Point ◽

Catalytic Chemistry

The evolution of antibacterial resistance has arisen as the main downside in fighting bacterial infections pushing researchers to develop novel, more potent and multimodal alternative drugs.Silver and its complexes have long been used as antimicrobial agents in medicine due to the lack of silver resistance and the effectiveness at low concentration as well as to their low toxicities compared to the most commonly used antibiotics. N-Heterocyclic Carbenes (NHCs) have been extensively employed to coordinate transition metals mainly for catalytic chemistry. However, more recently, NHC ligands have been applied as carrier molecules for metals in anticancer applications. In the present study we selected from literature two NHC-carbene based on acridinescaffoldand detailed nonclassicalpyrazole derived mono NHC-Ag neutral and bis NHC-Ag cationic complexes. Their inhibitor effect on bacterial strains Gram-negative and positivewas evaluated. Imidazolium NHC silver complex containing the acridine chromophore showed effectiveness at extremely low MIC values. Although pyrazole NHC silver complexes are less active than the acridine NHC-silver, they represent the first example of this class of compounds with antimicrobial properties. Moreover all complexesare not toxic and they show not significant activity againstmammalian cells (Hek lines) after 4 and 24 h. Based on our experimental evidence, we are confident that this promising class of complexes could represent a valuable starting point for developing candidates for the treatment of bacterial infections, delivering great effectiveness and avoiding the development of resistance mechanisms.

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Detection of SHV and TEM-type Extended spectrum β-lactamase in bacterial isolates recovered from clinical samples of patients attending military hospitals in South-South Nigeria

Zinc supplementation improves heme biosynthesis in rats exposed to lead ◽

10.18051/univmed.2019.v38.186-193 ◽

2019 ◽

Vol 38 (3) ◽

pp. 186

Author(s):

Helen Oroboghae Ogefere ◽

Samuel E. Iriah ◽

Ephraim Ehidiamen Ibadin

Keyword(s):

Antimicrobial Agents ◽

Clinical Laboratory ◽

Clinical Samples ◽

Bacterial Isolates ◽

Bacterial Strains ◽

Gram Negative ◽

Military Hospitals ◽

Extended Spectrum ◽

Phenotypic Method ◽

Antimicrobial Susceptibility Tests

Background Multi-drug resistant bacterial strains have been increasingly implicated in clinical infections worldwide and beta-lactamase production is one of the commonest mechanisms of resistance in these strains. This study investigated the prevalence of extended spectrum â-lactamase (ESBL)-producing isolates and determined the temoneira (TEM) and sulfhydryl variable (SHV) types implicated in two military hospitals in South-South Nigeria. Methods Three-hundred and eighty (380) consecutive non-duplicate bacterial isolates (Gram negative bacilli) recovered from clinical samples were identified following standard techniques. Antimicrobial susceptibility tests were performed for each isolate following the Clinical Laboratory Standards Institute guidelines. Bacterial isolates recovered which comprised Escherichia coli, Klebsiella spp, Proteus spp and Pseudomonas aeruginosa were screened for ESBL using a phenotypic method (double disc synergy test). All positive isolates were screened for TEM and SHV genes by PCR method. Results Sixty-five isolates (17.1%) were ESBL producing using phenotypic method, E. coli showed the highest ESBL prevalence (24.3%). One isolate was SHV positive (1.5%), 8 (12.3%) were TEM positive while 3 (4.6%) isolates harbored both SHV and TEM genes. Fluoroquinolone - ofloxacin showed marked activity against ESBL-producing isolates (90.8%) while the least active were ceftriaxone (9.2%), ceftazidime (3.1%) and ampicillin (1.5%). Conclusion This study demonstrated that 17.1% of Gram-negative bacilli were ESBL producers. Screening of clinical isolates for ESBL should be implemented. The findings of this study suggest the need for caution in the use of antimicrobial agents in order to curb the incidence of antimicrobial resistance.

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Investigation of the Biochemical and Ultrastructural Mechanisms Underlying the Antimicrobial Activity of Mimusops spp. Extracts

Baghdad Science Journal ◽

10.21123/bsj.2020.17.2.0452 ◽

2020 ◽

Vol 17 (2) ◽

pp. 0452

Author(s):

Mahmoud S.M. Mohamed ◽

Gehad Abdelmohsen ◽

Gouda T. M. Dawoud

Keyword(s):

Bacterial Infections ◽

High Performance ◽

Antimicrobial Agents ◽

Antimicrobial Effect ◽

Inhibition Zone ◽

Antibacterial Activities ◽

Ultrastructural Changes ◽

Bacterial Strains ◽

Leaf Extracts ◽

Traditional Medicines

Antibiotic resistance is the major growing threat facing the pharmacological treatment of bacterial infections. Therefore, bioprospecting the medicinal plants could provide potential sources for antimicrobial agents. Mimusops, the biggest and widely distributed plant genus of family Sapotaceae, is used in traditional medicines due to its promising pharmacological activities. This study was conducted to elucidate the antimicrobial effect of three unexplored Mimusops spp. (M. kummel, M. laurifolia and M. zeyheri). Furthermore, the mechanisms underlying such antibacterial activity were studied. The Mimusops leaf extracts revealed significant antibacterial activities against the five tested bacterial strains with a maximum inhibition zone diameter of 22.0 mm against B. subtilis compared with standard antibiotic ciprofloxacin. The minimal inhibitory and bactericidal concentration values against tested Gram-positive and Gram-negative bacterial strains ranged from 3.15-12.5 µg/ml. However, weak antifungal effect was recorded against Candida albicans with MIC value ˃25 µg/ml. The 1, 1-diphenyl-2-picrylhydrazyl (DPPH) assay showed that M. caffra was the best antioxidant (IC50=14.75±0.028 µg/ml), while M. laurifolia was the least one (IC50=34.22±0.014 µg/ml). The phenolics in plant leaves extracts were identified and quantified by high performance liquid chromatography (HPLC) which revealed the presence of seven phenolic acids and four flavonoids. The abundant phenolic compounds were rutin (5.216±0.067 mg/g dried wt.) and gallic acid (0.296±0.068 mg/g) followed by myricetin (0.317±0.091 mg/g) then kaempferol (0.113±0.049 mg/g) as flavonoids. The antibacterial mechanism of M. laurifolia extract, as a representative species, induces ultrastructural changes in the model bacterium Staphylococcus aureus with cell wall and plasma membrane lysis as revealed by transmission electron microscopy. Overall, Mimusops species (M. laurifolia, M. kummel and M. zeyheri) are promising natural alternative sources for antimicrobial agents.

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Characterization and Rate of Killing of Conjugated Silver Nanoparticles Against Selected Clinical Bacterial Isolates

10.53365/nrfhh/145339 ◽

2022 ◽

Author(s):

Stephen Oloninefa ◽

Abalaka Moses Enemaduku ◽

Daniyan Saﬁya Yahaya ◽

Mann Abdullahi

Keyword(s):

Drug Delivery ◽

Silver Nanoparticles ◽

Bacterial Infections ◽

Antimicrobial Agents ◽

Silver Ions ◽

Multidrug Resistant ◽

Bacterial Isolates ◽

Target Sites ◽

Alternative Agent ◽

The Fourier Transform

The menace of drug resistance, bioavailability and drug delivery to the target sites has motivated researchers to search for new antimicrobial agents from medicinal plants and subsequently use them for the biosynthesis of silver nanoparticles for effective killing of bacteria challenging to kill using crude extracts. The biosynthesis of silver nanoparticles was done using aqueous extract (AQE) of Euphorbia heterophylla, while characterization and the killing rate of conjugated silver nanoparticles (CAgNPs) were carried out using standard methods. The maximum wavelength obtained for CAgNPs was 410.33 nm, while the size distribution was 237.8 d.nm. The Fourier Transform Infra-Red result showed O-H (3308.94 cm-1), which is responsible for stabilising and reducing silver ions, while the Transmission Electron Microscopy revealed the presence of monodispersed spherical shapes CAgNPs. The Energy Dispersive Spectroscopy confirmed the presence of silver. There were reductions in the clinical bacterial isolates exposed to CAgNPs as the exposure time increased. Escherichia coli was killed between 6-7 h while Salmonella typhimurium was killed at the seven has the value of 0.00 log10 CFU/ml was recorded respectively. However, there were increments in the populations of clinical bacterial isolates in control as the time of exposure increased. Therefore, the study suggests that the CAgNPs exhibit intense antimicrobial activity and the potential to be developed as an alternative agent to treat bacterial infections, curb multidrug-resistant bacterial infection, and promote speedy drug delivery to the target sites.

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Synthesis, Antimicrobial Evaluation and In silico Studies of Novel 2,4- disubstituted-1,3-thiazole Derivatives

Letters in Drug Design & Discovery ◽

10.2174/1570180815666180502120042 ◽

2018 ◽

Vol 16 (2) ◽

pp. 160-173 ◽

Cited By ~ 2

Author(s):

Mir Mohammad Masood ◽

Mohammad Irfan ◽

Shadab Alam ◽

Phool Hasan ◽

Aarfa Queen ◽

...

Keyword(s):

In Silico ◽

Bacterial Infections ◽

Antimicrobial Agents ◽

Docking Studies ◽

Bacterial Strains ◽

Thiazole Derivatives ◽

Standard Drug ◽

Hek 293 ◽

In Silico Studies

Background: 2,4-disubstituted-1,3-thiazole derivatives (2a–j), (3a–f) and (4a–f) were synthesized, characterized and screened for their potential as antimicrobial agents. In the preliminary screening against a panel of bacterial strains, nine compounds showed moderate to potent antibacterial activity (IC50 = 13.7-90.8 μg/ml). Methods: In the antifungal screening, compound (4c) displayed potent antifungal activity (IC50 = 26.5 µg/ml) against Candida tropicalis comparable to the standard drug, fluconazole (IC50 = 10.5 µg/ml). Based on in vitro antimicrobial results, compounds 2f, 4c and 4e were selected for further pharmacological investigations. Hemolytic activity using human red blood cells (hRBCs) and cytotoxicity by MTT assay on human embryonic kidney (HEK-293) cells revealed non-toxic nature of the selected compounds (2f, 4c and 4e). To ascertain their possible mode of action, docking studies with the lead inhibitors (2f, 4c and 4e) were performed using crystal structure coordinates of bacterial methionine aminopeptidases (MetAPs), an enzyme involved in bacterial protein synthesis and maturation. Results: The results of in vitro and in silico studies provide a rationale for selected compounds (2f, 4c and 4e) to be carried forward for further structural modifications and structure-activity relationship (SAR) studies against these bacterial infections. Conclusion: The study suggested binding with one or more key amino acid residues in the active site of Streptococcus pneumoniae MetAP (SpMetAP) and Escherichia coli MetAP (EcMetAP). In silico physicochemical properties using QikProp confirmed their drug likeliness.

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PREVALENCE OF CTX-M-PRODUCING GRAM-NEGATIVE UROPATHOGENS IN SOKOTO, NORTH-WESTERN NIGERIA

International Journal of Pharmacy and Pharmaceutical Sciences ◽

10.22159/ijpps.2020v12i1.35863 ◽

2019 ◽

pp. 21-25

Author(s):

NUHU TANKO ◽

R. O. BOLAJI ◽

B. O. OLAYINKA ◽

O. B. B. EUGENE

Keyword(s):

Bacterial Infections ◽

Antimicrobial Agents ◽

Klebsiella Oxytoca ◽

Enterobacter Aerogenes ◽

Edwardsiella Tarda ◽

Diffusion Method ◽

Gram Negative ◽

Extended Spectrum Beta Lactamase ◽

Amoxicillin Clavulanate ◽

Synergy Test

Objective: Infections of the urinary tract remains one of the most common bacterial infections with many implicated organisms being Gram-negative, which are increasingly resistant to antimicrobial agents. The aim of the study was to evaluate the resistance of ESBL producing Gram-negative enterobacteriaceae to commonly prescribed antibiotics and the prevalence of CTX-M genes from these isolates using polymerase chain reaction (PCR). Methods: The isolates were collected from urine over a period of 4 mo and studied, and were identified using Microgen Identification Kit (GN-ID). Susceptibility testing was performed by the modified Kirby Bauer disc diffusion method, and results were interpreted according to Clinical and Laboratory Standard Institute (CLSI). Extended-Spectrum Beta-Lactamase (ESBL) production was detected by the double-disc synergy test (DDST). Molecular characterization was based on the isolates that were positive for the phenotypic detection of ESBL. Results: Sixty one (61) isolates of Gram-negative uropathogens were identified. Of these, 19 (31.2%) were E. coli, 15 (24.6%) were Salmonella arizonae, Klebsiella pneumoniae were 7 (11.5%), Klebsiella oxytoca were 3 (4.9%), Enterobacter gergoviae were 6 (9.8%), 4 (6.6%) were Citrobacter freundii, 4 (6.6%) were Serratia marscence, and 1 (1.6%) were Enterobacter aerogenes, Proteus mirabilis, and Edwardsiella tarda each. Analysis of the bacterial susceptibility to antibiotics revealed most of them to be generally resistant to cotrimoxazole (73.3%), nalidixic acid (66.7%), norfloxacin (53.5%), ciprofloxacin (50.5%), gentamicin (48.6%), amoxicillin/clavulanate (45%), and the least resistant was displayed in nitrofurantoin (30%). Of the 15 ESBL producers, 11 (73.3%) were harbouring bla CTX-M genes. Conclusion: The study revealed a high susceptibility to nitrofurantoin, whereas susceptibility to cotrimoxazole was lowest. It further portrays a high prevalence of enterobacteriaceae isolates harbouring bla CTX-M genes in Sokoto metropolis.

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Graphene Matrices as Carriers for Metal Ions against Antibiotic Susceptible and Resistant Bacterial Pathogens

Coatings ◽

10.3390/coatings11030352 ◽

2021 ◽

Vol 11 (3) ◽

pp. 352

Author(s):

Anthony J. Slate ◽

Nathalie Karaky ◽

Grace S. Crowther ◽

Jonathan A. Butler ◽

Craig E. Banks ◽

...

Keyword(s):

Antimicrobial Activity ◽

Metal Ions ◽

Bacterial Infections ◽

Antimicrobial Agents ◽

Therapeutic Option ◽

Bacterial Strains ◽

Graphene Foam ◽

Coating Method ◽

Resistant Strains ◽

Specific Metal

Due to the ever-increasing burden of antimicrobial-resistant (AMR) bacteria, the development of novel antimicrobial agents and biomaterials to act as carriers and/or potentiate antimicrobial activity is essential. This study assessed the antimicrobial efficacy of the following ionic metals, silver, gold, palladium, platinum, zinc, and gallium alone and in combination with graphene matrices (which were coated via a drop casting coating method). The graphene foam was utilized as a carrier for the ionic metals against both, antibiotic susceptible and resistant bacterial strains of Acinetobacter baumannii,Staphylococcus aureus, Klebsiella pneumoniae and Pseudomonas aeruginosa. Ionic gold, palladium and platinum demonstrated the greatest antimicrobial activity against the susceptible and resistant strains. Scanning electron microscopy (SEM) visualized cellular ultrastructure damage, when the bacteria were incubated upon the graphene foam alone. This study suggests that specific metal ions applied in combination with graphene foam could present a potential therapeutic option to treat AMR bacterial infections. The application of the graphene foam as a potential carrier could promote antimicrobial activity, provide a sustained release approach and reduce possible resistance acquisition. In light of this study, the graphene foam and ionic metal combinations could potentially be further developed as part of a wound dressing.

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Synergistic Effect of the Combination of Commercial Essential Oils with Standard Antibiotics: In vitro Evaluation

Biological Sciences - PJSIR ◽

10.52763/pjsir.biol.sci.63.3.2020.242.252 ◽

2020 ◽

Vol 63 (3) ◽

pp. 242-252

Author(s):

Aneela Mehboob ◽

Tanveer Abbas

Keyword(s):

Staphylococcus Aureus ◽

Antibacterial Activity ◽

Essential Oils ◽

Bacterial Infections ◽

Antimicrobial Agents ◽

Nigella Sativa ◽

Citrus Limon ◽

Bacterial Strains ◽

Lavandula Angustifolia

The aim of this investigation was to determine the antibacterial activity of essential oils and to assess the outcomes produced by the combinations of antibiotics and essential oils. To execute this research, gold standard and conventional methods were used. Antibacterial potency of five essential oils namely Citrus limon, Elettaria cardamomum, Lavandula angustifolia, Nigella sativa and Prunus dulcis were tested against Escherichia coli, Serratia fonticola, Serratia liquefaciens, Citrobacter freundii and Staphylococcus aureus recouped from street foods of Karachi. Among five of them, Citrus limon and Lavandula angustifolia were the most potent essential oils showing highest antibacterial activity in their undiluted form with the exception of Staphylococcus aureus but their mix at different concentrations successfully inhibited the growth of Staphylococcus aureus and Serratia fonticola. Synergistic outcomes were achieved against all the tested bacterial strains from the mix of essential oils and antibiotics, however antagonistic results were also obtained. This exploration underpins the application of essential oils alone and in combinations with antimicrobial agents to improve the affectability of ineffective drugs and aides in the advancement of new antimicrobial drugs to treat bacterial infections utilizing therapeutic plants.

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Pharmacological Exploitation of Non-Steroidal Anti-inflammatory Drugs as Potential Sources of Novel Antibacterial Agents

Anti-Infective Agents ◽

10.2174/2211352516666181008114542 ◽

2019 ◽

Vol 17 (2) ◽

pp. 81-92

Author(s):

Ebrahim M. Yimer ◽

Ousman A. Mohammed ◽

Seid I. Mohammedseid

Keyword(s):

Antimicrobial Resistance ◽

Bacterial Infections ◽

Antibacterial Agents ◽

Antimicrobial Agents ◽

Bacterial Strains ◽

Antiinflammatory Drugs ◽

Potential Sources ◽

Inflammatory Drugs ◽

Anti Inflammatory ◽

Therapeutic Alternatives

The ever-increasing threat of bacterial infections and antimicrobial resistance calls for a global effort to deal with this problem. This fast and universal dissemination of antimicrobialresistant bacterial strains resulted in the diminution of therapeutic alternatives for various infectious diseases. Besides, the unaffordability of efficacious antimicrobials coupled with the occurrence of unpleasant adverse effects calls for the exploration of alternative agents with possible antibacterial effect. All these challenges of microbes have posed new drives to the scientific communities. Researchers are now assessing the possible alternative antimicrobial agents for fighting bacterial infections and antimicrobial resistance. Therefore, this review emphasizes on the role of nonsteroidal anti-inflammatory agents as potential sources of novel antibacterial agents on which preliminary studies and randomized controlled trials had been performed. The review also deals with the possible antibacterial mechanism of actions and the likely effects of non-steroidal antiinflammatory drugs when combined along with conventional antibacterial agents.

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Magnitude of Biofilm Formation and Antimicrobial Resistance Pattern of Bacteria Isolated from Urinary Catheterized Inpatients of Jimma University Medical Center, Southwest Ethiopia

International Journal of Microbiology ◽

10.1155/2019/5729568 ◽

2019 ◽

Vol 2019 ◽

pp. 1-9 ◽

Cited By ~ 4

Author(s):

Netsanet Awoke ◽

Tesfaye Kassa ◽

Lule Teshager

Keyword(s):

Biofilm Formation ◽

Antimicrobial Agents ◽

Medical Center ◽

Bacterial Isolates ◽

Bacterial Strains ◽

Southwest Ethiopia ◽

Gram Negative ◽

Antimicrobial Susceptibility Pattern ◽

Study Participants ◽

Jimma University

Biofilm formation is one of the features of most bacteria. Catheterization in medicine is a source of highly resistant bacterial infections, and those bacteria respond poorly to antimicrobial therapy. Bacterial biofilm features were not described from catheterized inpatients in Ethiopia as its formation is known to afford antimicrobial resistance and challenge patient management. The aim of this study was to isolate catheter-associated urinary bacterial pathogens, their biofilm formation, and antimicrobial susceptibility pattern among inpatients of Jimma University Medical Center (JUMC) in Southwest Ethiopia. A prospective cross-sectional study was conducted among urinary catheterized inpatients of JUMC from February to August 2016. A total of 143 study participants were enrolled consecutively in this study. Urine samples were collected from catheterized patients and processed using a standard bacteriological protocol for isolation and identification. Evaluation ofin vitrobiofilm formation and antimicrobial susceptibility pattern of uropathogenic bacteria was done using microtiter plates and disk diffusion method, respectively. Data were cleaned, coded, and entered into SPSS version 20 for analysis. All statistical test values ofp<0.05were considered statistically significant. From all study participants, mean age was 44 years. Sixty bacterial strains were recovered from 57 urinary catheterized inpatients among which 54 of them were monomicrobial (94.7%). The remaining six bacterial strains were recovered from three study participants each with two bacterial isolates. The predominant bacterial isolates were Gram-negative bacteria withE. coliturning out first. About 80% of bacterial isolates were biofilm formers. The majority of the bacteria were resistant to commonly prescribed antimicrobial agents. In conclusion, the majority of bacterial uropathogen isolates were Gram-negative, biofilm formers, and resistant to commonly prescribed antimicrobial agents. Relatively ciprofloxacin, nitrofurantoin, and amikacin were highly effective against most isolated bacteria.

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