Multifunctional in vitro, in silico and DFT analyses on antimicrobial BagremycinA biosynthesized by Micromonospora chokoriensis CR3 from Hieracium canadense.

Among the actinomycetes in the rare genera, Micromonospora is of great interest since it has been shown to produce novel therapeutic compounds. Particular emphasis is now on its isolation from plants since its population from soil has been extensively explored. The strain CR3 was isolated as an endophyte from the roots of Hieracium canadense, and it was identified as Micromonospora chokoriensis through 16S gene sequencing and phylogenetic analysis. The in-vitro analysis of its extract revealed it to be active against the clinical isolates of methicillin-resistant Staphylococcus aureus (MRSA) and Candida tropicalis (15 mm). No bioactivity was observed against Gram-negative bacteria, Escherichia coli ATCC 25922, and Klebsiella pneumoniae ATCC 706003. The Micromonospora chokoriensis CR3 extract was also analyzed through the HPLC-DAD-UV-VIS resident database, and it gave a maximum match factor of 997.334 with the specialized metabolite BagremycinA (BagA). The in-silico analysis indicated that BagA strongly interacted with the active site residues of the sterol 14-α demethylase and thymidylate kinase enzymes, with the lowest binding energies of - 9.7 and - 8.3 kcal/mol, respectively. Furthermore, the normal mode analysis indicated that the interaction between these proteins and BagA was stable. The DFT quantum chemical properties depicted BagA to be reasonably reactive with a HOMO-LUMO gap of (ΔE) of 4.390 eV. BagA also passed the drug-likeness test with a synthetic accessibility score of 2.06, whereas Protox-II classified it as a class V toxicity compound with high LD50 of 2644 mg/kg. The current study reports an endophytic actinomycete, M. chokoriensis, associated with H. canadense producing the bioactive metabolite BagA with promising antimicrobial activity, which can be further modified and developed into a safe antimicrobial drug.

Limosilactobacillus fermentum IKP 111 reduces pathogen load and improves immunity of broilers when challenged with Salmonella enteritidis.

In this study, we checked the effectiveness of L. fermentum IKP 111 in treating S. enteritidis infection in an in vivo study. Its oral administration to broiler chicks significantly reduced the colonization of S. enteritidis in the gut and there was a lower bacterial count of S. enteritidis in the droppings after infection. The administration of the probiotic L. fermentum IKP 111 also led to increase in weight gain in the broiler chicks as well as their immunomodulation against avian influenza virus (AIV) and Newcastle disease virus (NDV) as compared to the chicks challenged only with S. enteritidis. Our study provides evidence that the probiotic strain L. fermentum IKP 111 could be an alternate for controlling S. enteritidis infection while enhancing the gut health as well as the immune response of broiler chickens against viral infections.

One Health Assessment of Bacillus anthracis Incidence and Detection in Anthrax-Endemic Areas of Pakistan.

Anthrax, a severe zoonotic disease, is infrequently reported in anthrax-endemic regions of Pakistan. Despite clinical reports indicating its presence, particularly cutaneous anthrax, there is insufficient laboratory evidence regarding disease occurrence and environmental persistence. The present study aimed to confirm Bacillus anthracis presence, accountable for animal mortality and human infection, while exploring environmental transmission factors. Between March 2019 and July 2021, a total of 19 outbreaks were documented. Of these, 11 affected sheep/goats in Zhob district and 8 affected cattle/sheep in Bajour Agency. Clinical signs suggestive of Bacillus anthracis outbreak were observed in 11 animals. Blood and swab samples were collected for confirmation. The study followed a One Health approach, analyzing animal, environmental (soil/plant), and human samples. Of the 19 outbreaks, 11 were confirmed positive for anthrax based on growth characteristics, colony morphology, and PCR. Soil and plant root samples from the outbreak areas were collected and analyzed microscopically and molecularly. Cutaneous anthrax was observed in six humans, and swab samples were taken from the lesions. Human serum samples (n = 156) were tested for IgG antibodies against PA toxin and quantitative analysis of anthrax toxin receptor 1 (ANTXR1). Bacillus anthracis was detected in 65 out of 570 (11.40%) soil samples and 19 out of 190 (10%) plant root samples from the outbreak areas. Four out of six human samples from cutaneous anthrax lesions tested positive for Bacillus anthracis. Human anthrax seroprevalence was found to be 11% and 9% in two districts, with the highest rates among butchers and meat consumers. The highest ANTXR1 levels were observed in butchers, followed by meat consumers, farm employees, meat vendors, veterinarians, and farm owners. These findings highlight the persistence of anthrax in the region and emphasize the potential public health risks.

Genomic Diversity and Evolution of SARS-CoV-2 Lineages in Pakistan.

The emergence of SARS-CoV-2 variants has posed a challenge to disease control efforts worldwide. This study explored the genomic diversity and phylogenetic relationship of SARS-CoV-2 variants reported in Pakistan. Our objective was to understand the transmission dynamics of different lineages within the country. We retrieved and analyzed spike protein sequences from Pakistan and compared them with reference sequences reported worldwide. Our analysis revealed the clustering of Pakistan-origin isolates in nine different clades representing different regions worldwide, suggesting the transmission of multiple lineages within the country. We found 96 PANGO lineages of SARS-CoV-2 in Pakistan, and 64 of these corresponded to 4 WHO-designated variants: Alpha, Beta, Delta, and Omicron. The most dominant variants in Pakistan were Alpha (B.1.1.7), Beta (B.1.351), Delta (B.1.617.2, AY.108), and Omicron (BA.2.75, BA.5.2), and the N-terminal domain and receptor binding regions were the most hypervariable regions of the spike gene. Compared to the reference strain, characteristic substitutions were found in dominant variants. Our findings emphasize the importance of continuously monitoring and assessing nucleotide and residue substitutions over time to understand virus evolutionary trends better and devise effective disease control interventions.

Fatty acid based antimicrobials from Streptomyces sp. SORS-24, an endophyte isolated from Sonchus oleraceus.

Due to the rise in bacterial resistance towards various therapeutic agents, interest is now developing towards fatty acid based antimicrobials because of their non-specific mode of action. A strain SORS 24 isolated from Sonchus oleraceus (Sow thistle) showed significant activity against Escherichia coli ATCC 25922 (25 mm), Chlorella vulgaris (20 mm), Bacillus subtilis DSM 10 (ATCC 6051) and Pseudomonas sp. (15 mm). It displayed an LC50 value of 10 µg/ml against Artemia salina (Brine shrimp) nauplii and an EC50 value of 0.8 µg/ml in the (DPPH) diphenylpicrylhydrazyl antioxidant assay. The strain also displayed genotoxicity against a PolA deficient strain, E. coli K-12 AB 3027 (15 mm). Mass spectrometry (HPLC-MS) showed that the strain produced oleamide (9-Octadecenamide) and erucamide (13-Docosenamide). Both of the purified fatty acid amides showed prominent activity against B. subtilis DSM 10 (ATCC 6051) (20 mm) and E. coli ATCC 25922 (15 mm). Significant genotoxicity was observed against E. coli K-12 AB 3027 (15 mm). The 16S gene sequencing revealed that the strain belonged to species, Streptomyces tanashiensis. As far as our understanding, this is the first report of this species producing these fatty acid based antimicrobials.

Pharmacokinetics of thymoquinone in layer chickens following oral and intravenous administration.

Thymoquinone (TQ) is the major constituent of Nigella sativa and known to possess a variety of pharmacological effects. This study was designed to evaluate the pharmacokinetic profile of TQ following oral (PO) and intravenous (IV) administration in layer chickens. The layer chickens were equally divided into two groups (six chickens in each group, total 12 chickens), and TQ was administered via PO and IV routes. For PO route, the dose was 20 mg/kg b.w. and for IV route, 5 mg/kg b.w. was administered, respectively. A sensitive and accurate High-Performance Liquid Chromatography (HPLC) technique was validated for the quantification of TQ from plasma. The limit of detection (LOD) and limit of quantification (LOQ) were 0.02 µg/ml and 0.05 µg/ml, respectively with >80% recovery. Maximum plasma concentration (Cmax ) following PO and IV administration was 8.805 and 4.497 µg/ml, respectively, while time to reach at maximum concentration (Tmax ) was 1 and 0.1 hr, respectively. The elimination half-lives were recorded as 1.02 and 0.978 hr, whereas the mean residence times were 1.79 and 1.036 hr following both PO and IV administration, respectively. The 85% PO bioavailability was indicative that TQ could be used for various therapeutic purposes in layer chickens.

Fatty acids and their amide derivatives from endophytes: new therapeutic possibilities from a hidden source.

Fatty acid and their amide derivatives are natural self-defense agents in plants. They have been observed to be broadly bioactive against a variety of disease agents. The mechanism of action understood so far being their targeting the protein synthesis and causing leakage of the intracellular components. Owing to their broad bioactivity, the fatty acids and their amides as therapeutics can cover a wide range of indications such as cancer, bacterial infections, parasitic infection, inflammations, diabetes and obesity to name a few. The microorganisms residing inside the healthy plant tissues are a unique niche for exploration of novel bioactive compounds. The recent identification of fatty acid amide derivatives as well as prior reports from endophytes have drawn fresh attention to this unique source for their isolation. Hence, they represent an exciting opportunity for the development of new therapeutic agents against existing disease causative agents. In this paper, we will discuss the production of fatty acids and amide derivatives by plants and their associated endophytes. Their reported bioactivities establishing their potential benefit as possible therapeutic agents will also be examined.

Endophyte bioprospecting in South Asian medicinal plants: an attractive resource for biopharmaceuticals.

From the last several years, there has been an increasing interest in plant-associated bacteria commonly referred to as endophytes that reside asymptomatically in the internal plant tissues. This interest peaked since the last two decades due to the recognition that endophytes within medicinal plants have the capability to mimic and produce the bioactive metabolites of the host plant. A number of medicinal plants have been used for centuries by the people of South Asia to cure various diseases and this has led to abundant usage experience. Relating to prior ethanopharmacological experiences, scientists have searched for medicinal plants that could be valued sources for endophytes yielding novel metabolites of pharmaceutical importance. This review is therefore an effort to encompass the most recent efforts in the exploration of medicinal plants of South Asia and their endophytes.

Rare actinomycetes Nocardia caishijiensis and Pseudonocardia carboxydivorans as endophytes, their bioactivity and metabolites evaluation.

Two strains identified as Nocardia caishijiensis (SORS 64b) and Pseudonocardia carboxydivorans (AGLS 2) were isolated as endophytes from Sonchus oleraceus and Ageratum conyzoides respectively. The analysis of their extracts revealed them to be strongly bioactive. The N. caishijiensis extract gave an LC50 of 570 µg/ml(-1) in the brine shrimp cytotoxicity assay and an EC50 of 0.552 µg/ml(-1) in the DPPH antioxidant assay. Antimicrobial activity was observed against Methicillin resistant Staphlococcus aureus (MRSA) and Escherichia coli ATCC 25922 (14 mm), Klebsiella pneumoniae ATCC 706003 (13 mm), S. aureus ATCC 25923 (11 mm) and Candida tropicalis (20 mm). For the extract of P. carboxydivorans the EC50 was 0.670 µg/ml(-1) and it was observed to be more bioactive against Bacillus subtilis DSM 10 ATCC 6051 (21 mm), C. tropicalis (20 mm), S. aureus ATCC 25923 (17 mm), MRSA (17 mm), E. coli K12 (W1130) (16 mm) and Chlorella vulgaris (10 mm). The genotoxicity testing revealed a 20 mm zone of inhibition against the polA mutant strain E. coli K-12 AB 3027 suggesting damage to the DNA and polA genes. The TLC and bioautography screening revealed a diversity of active bands of medium polar and nonpolar compounds. Metabolite analysis by HPLC-DAD via UV/vis spectral screening suggested the possibility of stenothricin and bagremycin A in the mycelium extract of N. caishijiensis respectively. In the broth and mycelium extract of P. carboxydivorans borrelidin was suggested along with α-pyrone. The HPLC-MS revealed bioactive long chained amide derivatives such as 7-Octadecenamide, 9, 12 octadecandienamide. This study reports the rare actinomycetes N. caishijiensis and P. carboxydivorans as endophytes and evaluates their bioactive metabolites.

Larvicidal potential of Asteraceae family endophytic actinomycetes against Culex quinquefasciatus mosquito larvae.

Pakistan is blessed with plants of Asteraceae family with known medicinal background used for centuries by Hakims (traditional physicians). Keeping in mind the background of their anti-larval potential, a total of 21 endophytic actinomycetes were isolated from four Asteraceae plants and screened against the first and fourth instar stages of Culex quinquefasciatus Say mosquito larvae. Of the 21 isolates, 6 of them gave strong larvicidal activity (80-100% mortality) in the screening results and 4 isolates gave a potent larvicidal activity (100% mortality) at the fourth instar stage. These isolates belonged to different species within the actinomycetes group, namely Streptomyces albovinaceus and Streptomyces badius. This communication reports the larvicidal potential of endophytic actinomycetes residing within the native Asteraceae plants in Pakistan. The study suggests further exploration through large-scale productions leading to the identification of the larvicidal compounds.

Biotechnological potential of endophytic actinomycetes associated with Asteraceae plants: isolation, biodiversity and bioactivities.

Endophytic actinomycetes from five Asteraceae plants were isolated and evaluated for their bioactivities. From Parthenium hysterophorus, Ageratum conyzoides, Sonchus oleraceus, Sonchus asper and Hieracium canadense, 42, 45, 90, 3, and 2 isolates, respectively, were obtained. Of the isolates, 86 (47.2 %) showed antimicrobial activity. Majority of the isolates were recovered from the roots (n = 127, 69.7 %). The dominant genus was Streptomyces (n = 96, 52.7 %), while Amycolatopsis, Pseudonocardia, Nocardia and Micromonospora were also recovered. Overall, 36 of the 86 isolates were significantly bioactivity while 18 (20.9 %) showed strong bioactivity. In total, 52.1 and 66.6 % showed potent cytotoxicity and antioxidant activities. The LC50 for 15 strains was <20 µg/ml. Compared to the ascorbate standard (EC50 0.34 µg/ml), all isolates gave impressive results with notable EC50 values of 0.65, 0.67, 0.74 and 0.79 µg/ml.

Screening of endophytic Streptomycetes isolated from Parthenium hysterophorus L. against nosocomial pathogens.

Parthenium hysterophorus L. is an obnoxious weed of the family asteraceae recognized for its detrimental effects and significant economic losses to agriculture. In this study 42 endophytic streptomycetes strains were isolated from its roots and leaves. The isolates were identified by morphological, microscopic, biochemical and physiological characterization as members of genus Streptomyces. In 16S rRNA gene sequencing the selected isolates exhibited maximum similarity with Streptomyces rochei (99%), Streptomyces litmocidini (99%), Streptomyces enissocaesili (99%), Streptomyces djakartensis (99%), Streptomyces olivaceus (99%), Streptomyces spp (99%), Streptomyces plicatus (99%), Streptomyces geysiriensis (99%) and Streptomyces vinaceusdrappus (99%). In biological screening the crude extracts of 12 strains exhibited significant antimicrobial activity against multi drug resistant nosocomial pathogens including Pseudomonas, Enterobacter, Bacillus, Escherichia coli, Staphlococcus aureus and Candida albicans. In chemical screening by thin layer chromatography (TLC) the extracts exhibited an impressive diversity of the bioactive secondary metabolites. Additionally high performance liquid chromatography (HPLC-UV) chromatographs revealed many impressive peaks of unidentified bioactive metabolites. As such this is a first study reporting the isolation, identification and screening of endophytic Streptomyces from the invasive weed. The results provide an insight into an untapped endophytic environment yet to be explored which might be a promising source of lead antimicrobial agents.