1.Molecular characterization of mycotoxin-producing Aspergillus parasiticus and sensitivity pattern to different disinfectants
Zunira Mughis ; Muhammad Asad Ali ; Aftab Ahmad Anjum ; Muhammad Ovais Omer ; Mateen Abbas ; Maria Najeeb
Malaysian Journal of Microbiology 2022;18(5):524-532
Aims:
The study was aimed to isolate and characterize the mycotoxin-producing filamentous Aspergillus parasiticus from the feed samples. The sensitivity pattern of the isolates was assessed against different disinfectants.
Methodology and results:
Fifty different feed samples were screened for A. parasiticus isolation. Isolates were subjected to macroscopic and microscopic characterization. Polymerase chain reaction was performed to confirm the isolates at the genomic level. Mycotoxin producing potential of the isolates was assessed by thin-layer chromatography (TLC). To quantify the toxins, high performance liquid (HPLC) was employed. The antifungal potential of disinfectants was determined by the well diffusion method followed by minimum inhibitory concentration (MIC) calculation. Out of twenty isolates of A. parasiticus, 11(55%) isolates were observed positive for toxin production. Three toxigenic isolates (AspP2, AspP4 and AspP8) were selected to evaluate their susceptibility against disinfectants by well diffusion method. AspP2 produced maximum (5.90 ng/mL) toxin, followed by AspP4 (3.11 ng/mL) and AspP8 (18.47 ng/mL). Terralin showed maximum fungicidal activity with 29.66 ± 8.08 mm zone of inhibition at 0.42 μg/mL MIC. Hypochlorite and Instru Star showed 99% disinfection with 30, 60 and 90 min contact time (6 mean log reduction) for all A. parasiticus isolates. Alpha Guard inhibited growth after 15 min contact time for all the isolates.
Conclusion, significance and impact of study
This study provides data indicating the contamination of feed samples with mycotoxin-producing A. parasiticus isolates and their sensitivity against commercially available disinfectants. Use of these disinfectants in appropriate concentrations and time could help prevent the contamination of food, feed and healthcare settings with the fungal species.
Mycotoxins
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Aspergillus
2.Antibiotic resistance modulation of Clostridium perfringens type D using indigenous plants extracts
Iqra Ilyas ; Muhammad Asad Ali ; Aftab Ahmad Anjum ; Muhammad Nawaz ; Sehrish Firyal
Malaysian Journal of Microbiology 2024;20(no.1):58-66
Aims:
The study was aimed to explore the antimicrobial potential of ethanolic leaf extracts of Eucalyptus globulus, Moringa oliefera, Syzygium cumini and Citrus limon against antibiotic-resistant Clostridium perfringens type D (n=5).
Methodology and results:
Antibiotic resistance pattern of C. perfringens type D isolates against tetracycline, gentamicin, ceftriaxone, amoxicillin and streptomycin was evaluated by disc diffusion method. Well diffusion and micro broth dilution methods were used to determine the anti-bacterial activity, sub-inhibitory concentrations and antibiotic resistance modulating effects of the plant extracts. Ethanolic extract of E. globules was selected to evaluate its modulatory impact and subjected to GC-MS analysis to separate and identify the phytochemicals. The results showed that the isolates were resistant to gentamicin (0 ± 0.00 mm), streptomycin (0 ± 0.00 mm), tetracycline (13.2 ± 2.28 mm) and ceftriaxone (0 ± 0.00 mm) while sensitive to amoxicillin (23.8 ± 1.30 mm) and tetracycline (13.2 ± 2.28 mm). Eucalyptus globulus exhibited the maximum anti-bacterial activity with a zone of inhibition (ZOI) of 14.6 ± 0.54 mm and
minimum inhibitory concentration (MIC) (1500 ± 947.85 µg/mL). Other plant extracts (M. oliefera, S. cumini and C. limon) also showed anti-bacterial activity but couldn’t modulate the resistance. The activity of ceftriaxone associated with E. globulus extract was improved with 20.2 ± 0.20 mm ZOI at 78.125 µg/mL sub-inhibitory concentration.
Conclusion, significance and impact of study:
The study results indicate the possible use of the ethanolic extract of E. globulus alone or in combination with common antibiotics for the treatment of C. perfringens infections in small ruminants.
3.Antibacterial potential of indigenous medicinal plants against methicillin-resistant Staphylococcus aureus isolated from septic wounds
Sana Saif ; Humaira Majeed Khan ; Aftab Ahmad Anjum ; Tehreem Ali ; Allah Bukhsh ; Rabia Manzoor ; Syed Muhammad Faheem Ahmad
Malaysian Journal of Microbiology 2022;18(4):389-397
Aims:
This study was aimed to screen indigenous medicinal plants for their antibacterial potential against methicillin-resistant Staphylococcus aureus (MRSA).
Methodology and results:
Three indigenous plants (Nigella sativa, Zingiber officinale and Calotropis procera) and thymoquinone were screened for antibacterial activity against MRSA, isolated from septic wounds of patients admitted to Mayo Hospital Lahore, Pakistan. Isolated bacteria were screened for methicillin and cefoxitin resistance by the Kirby-Bauer method, followed by mecA gene-specific polymerase chain reaction (PCR). Confirmed MRSA was processed for antibacterial activity of plant extracts and thymoquinone followed by cytotoxicity assay of plant extract having least minimum inhibitory concentration (MIC) value. Out of total samples (n=100), S. aureus (29%), MRSA (26%) and vancomycin-resistant S. aureus (VRSA) (21.7%) isolates were recovered based on morphology, biochemical profile and antibiotic susceptibility testing. Nigella sativa showed the highest antibacterial activity (10.06 ± 6.53 mm) against MRSA followed by Z. officinale (4.06 ± 3.72 mm) and C. procera (3.65 ± 3.33 mm) in comparison to standard thymoquinone (17.93 ± 10.14 mm). The least MIC value recorded was for Z. officinale at 36.89 ± 3.75 μg/mL. Zingiber officinale was the most effective antibacterial agent, followed by N. sativa and C. procera and non-toxic for eukaryotic cells at all tested concentrations (1500 μg/mL to 2.92 μg/mL).
Conclusion, significance and impact of study
It was concluded that Z. officinale may be used as an effective alternative for treating septic wound infection in local or topical preparations. As pathogenic S. aureus is becoming life-threatening among antibiotic-resistant bacteria and traditional plants are in used for centuries to treat septic wound infections.
Plants, Medicinal
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Methicillin-Resistant Staphylococcus aureus--isolation &
;
purification
;
4.Biofuel production potential of indigenous isolates of Scenedesmus sp. from lake water in Pakistan
Muhammad Imran Najeeb ; Mansur-ud-Din Ahmad ; Aftab Ahmad Anjum ; Azhar Maqbool ; Muhammad Asad Ali ; Muhammad Nawaz ; Tehreem Ali ; Rabia Manzoor
Malaysian Journal of Microbiology 2022;18(4):380-388
Aims:
This paper presents the report on biodiesel and biogas production at a laboratory scale from Scenedesmus strain.
Methodology and results:
Previously isolated and identified Scenedesmus were grown in 10 Liter flask using BG-11 media at 16 h light and 8 h dark cycle. Oven-dried biomass (20 g) from 16-day-old culture of Scenedesmus was finely grounded and subjected to lipids extraction by chloroform-methanol-NaCl mixture. Microalgal lipids (6 mL) were subjected to transesterification by using NaOH leading to the production of 5 mL biodiesel and 4 mL of glycerin. Biodiesel was rich in methyl esters of linoleic acid, phosphorothioc acid and dodecanoic acid, as shown by gas chromatography-mass spectrometry (GC-MS) analysis. Oven-dried microalgae (2 g) without lipid extraction and leftover biomass (2 g) after lipid extraction were subject to biogas production through anaerobic digestion. Biogas (34, 27 and 19 mL) were recorded respectively in oven-dried whole biomass; lipid extracted biomass and control over a period of 15 days of anaerobic digestion.
Conclusion, significance and impact of study
It was concluded that water bodies are rich in diverse algae, especially Scenedesmus sp., and this algae can be cultured to produce biodiesel and biogas. But the lipid accumulation potential of microalgae requires special treatment and lipid extraction methods are not up to the mark, which is a major bottleneck in biofuel production from microalgae.
Biofuels
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Scenedesmus--isolation &
;
purification