In silico Targeting, inhibition and analysis of polyketide synthase enzyme in Aspergillus ssp

Aflatoxins are toxic and carcinogenic components produced by some Aspergillus species such as Aspergillus flavus. Polyketide synthases enzyme (PKS) plays a central role in aflatoxin s biosynthesis of in Aspergillus flavus, especially the product template (PT) domain, which controls the aldol cyclization of the polyketide forerunner during the biosynthesis of the aflatoxin pathway process. Here, we apply the in silico approaches to validate 623 natural components obtained from the South African Natural Compound Database (SANCDB), to distinguish the PT domain s prospected inhibitors. From the 623 compounds, docking results showed that there are 330 different compounds with energy binding lower than the natural substrate (palmitic acid or PLM) of the Product Templet domain (PT). Three factors were selected to determine the best 10 inhibiting components; 1) energy binding, 2) the strengthen chemical interactions, 3) the drug-likeness. The top ten inhibiting components are kraussianone 6, kraussianone 1, neodiospyrin, clionamine D, bromotopsentin, isodiospyrin, spongotine A, kraussianone 3, 14β-Hydroxybufa-3,5,20,22-tetraenolide and kraussianone 7. The chemical interactions between 3HRQ domain and the natural substrate in the active site amino acids are highly similar to the 3HRQ with the top ten components, but the main differences are in the binding energy which is the best in the top ten ligands. Those ten components give successful inhibition with PT domain which will lead to the formula to be used for inhibition and control aflatoxin contamination of agriculture crop yields and lessen the degree of harming and sicknesses that are coming about because of acquiring measures of aflatoxin.

Does elective orthopaedic surgery in pandemic era increase risk of developing COVID-19? A combined analysis of retrospective and prospective study at Cipto Mangunkusumo Hospital, Jakarta, Indonesia

BACKGROUND

To date, no recommendations have been published on when and how to start again carrying out elective, non-urgent surgery on COVID-19-negative patients after the epidemic peak has been reached in a given country or region and the pressure on healthcare facilities, healthcare workers and resources has been released by so far that elective surgery procedures can be safely and ethically programmed again. This study aims to investigate whether elective orthopaedic surgery will increase the risk of developing COVID-19.

MATERIALS AND METHODS

This was a combined retrospective and prospective studies performed at a national tertiary hospital in Jakarta, Indonesia. Subjects were patients who underwent elective orthopaedic surgeries at our institution from April to May 2020. Those who were previously infected with COVID-19 from polymerase chain reaction (PCR) reverse transcriptase (RT) examination obtained via nasopharynx and oropharynx swab, as well as those who were reluctant to participate were excluded from the study.

RESULTS

A total of 35 subjects (mean age 32.89 ± 17.42) were recruited. Fifteen (42.9%) subjects were male, and 20 subjects (57.1%) were female. Mean duration of surgery was 240 min with the longest and shortest duration of 690 and 40 min, respectively. General anaesthesia was performed in the majority of cases in 18 surgeries (51.4%) with local anaesthesia as the least in 2 surgeries (5.7%). Length of stay of our study was 6 days of average. None of the patients developed symptoms suggestive of COVID-19 infection.

CONCLUSION

We found that elective orthopaedic surgery may not be associated with increased cases of COVID-19 cases. However, our study was limited by short duration of follow-up. Further studies are required in order to investigate the affect of undergoing elective surgery and the number of COVID-19 cases.

Lack of Clinical Benefit of Implantoplasty to Improve Implant Survival Rate

The objective of this study was to compare postsurgical outcomes of resective treatment for peri-implantitis with and without implant surface modification (implantoplasty [IP]). This was accomplished by a retrospective analysis with data from patients with ≥1 implant who were surgically treated for peri-implantitis by resective therapy. Patients were divided into 2 groups regarding treatment approach: IP (test) and no IP (control). Retrospective data were obtained after implant placement (T0) and the day of peri-implantitis surgical treatment (T1). Patients were then recalled (≥1 y after T1) for clinical and radiographic examination (T2). The findings were conclusive. A total of 41 patients (68 implants; mean ± SD follow-up, 41.6 ± 24.4 mo) were included in this study. The survival rate at the implant level was 90% in the test group and 81.6% in the control group ( P > 0.05). Multilevel regression analysis showed that the probability of implant failure was influenced by marginal bone loss (MBL) at T1 and not surgical modality. For example, peri-implantitis defects ≥50% and 25% to 50% MBL were 18.6 and 8.86 times more likely to lose the implant, respectively, when compared with <25% MBL. Nonetheless, MBL changes were similar in the test and control groups ( P = 0.592). Similarly, changes in bleeding on probing, probing pocket depth, and suppuration at T2 did not differ between groups ( P > 0.05). Multilevel regression analysis indicated that clinical improvement of these parameters was influenced by the number of supportive peri-implant therapy visits ( P < 0.01). The results demonstrate little difference between the procedures. Regardless of the implant surface modification (IP) being performed or not, the survival rate of implants treated for peri-implantitis was primarily influenced by the amount of bone loss at the time of treatment. Other clinical parameters (MBL, probing pocket depth, bleeding on probing, suppuration) were influenced by the frequency of supportive peri-implant therapy visits and not by the IP procedure (ClinicalTrials.gov NCT04259840).

Acaricidal activity of the essential oils from Citrus hystrix (Rutaceae) and Cymbopogon citratus (Poaceae) on the cattle tick Rhipicephalus (Boophilus) microplus larvae (Acari: Ixodidae)

Rhipicephalus (Boophilus) microplus serves as an important ectoparasite of livestock and a vector of several pathogens resulting in diseases, subsequently affecting the agricultural field as well as the economy. The extensive use of synthetic acaricides is known to cause resistance over time and therefore a much safer, effective and environmentally friendly alternative to overcome tick infestation should be implemented. Larval immersion tests (LIT) were done to evaluate the effects of Citrus hystrix (Family: Rutaceae) and Cymbopogon citratus (Family: Poaceae) essential oils (EOs) for their individual and combined (1:1) acaricidal activity against the cattle tick. Results showed that LC₅₀ and LC₉₀ values in 24 and 48 hours for Cit. hystrix EO were 11.98% and 24.84%, and 10.95% and 21.71% respectively. LC50 and LC90 values for Cym. citratus EO were 1.21% and 6.28%, and 1.05% and 6.12% respectively. The mixture of EOs from two plants in 1:1 ratio (Cit. hystrix 50%: Cym. citratus 50%) was found to exhibit antagonistic effect (synergistic factor < 1). The 24 hours and 48 hours LC₅₀ and LC₉₀ values for combined EOs were 1.52% and 2.84%, and 1.50% and 2.76% respectively. Individual and combined essential oils were subjected to qualitative analysis using gas chromatography-mass spectrometry (GC-MS) to screen the chemical components present in EOs. Our results showed that the combination of Cit. hystrix and Cym. citratus at 1:1 ratio resulted in an antagonistic effect and the use of Cym. citratus alone is more toxic to R. (B.) microplus, making it a better alternative to chemical based acaricide.

Antimicrobial resistance of Staphylococcus species isolated from Lebanese dairy-based products

The study evaluated the antimicrobial resistance of molecularly characterized strains of Staphylococcus aureus and S. saprophyticus isolated from 3 Lebanese dairy-based food products that are sometimes consumed raw: kishk, shanklish and baladi cheese. Suspected Staphylococcus isolates were identified initially using standard biochemical tests, then strains that were confirmed by polymerase chain reaction (29 S. aureus and 17 S. saprophyticus) were evaluated for their susceptibility to different antimicrobials. The highest levels of contamination with staphylococci were in baladi cheese. Resistance rates ranged from 67% to gentamicin to 94% to oxacillin and clindamycin. The results suggest that these locally made dairy-based foods may act as vehicles for the transmission of antimicrobial-resistant Staphylococcus spp.

Osteonecrosis of the jaw: a rare and devastating side effect of bisphosphonates

Evidence has emerged that bisphosphonate use in cancer patients is associated with osteonecrosis of the jaw. This form of osteonecrosis has been termed bisphosphonate induced osteonecrosis of the jaw (BIONJ). BIONJ is commonly precipitated by a tooth extraction in patients treated with long term, potent, high dose intravenous bisphosphonates for the management of myeloma, breast or prostate cancer. The overall prevalence of BIONJ is about 5% in patients with these malignancies. Current evidence shows that the risk of BIONJ in non-cancerous patients, such as those with osteoporosis, is very low and appears to be comparable with that of the general population. Prescribing physicians need to encourage cancer patients to see their dentists before the initiation of bisphosphonate treatment, and regularly thereafter.

Antimicrobial resistance of Listeria monocytogenes isolated from dairy-based food products

In this study Listeria monocytogenes (L. monocytogenes) was isolated from three traditionally consumed Lebanese dairy-based food products. One hundred and sixty four samples (45 samples of Baladi cheese, 36 samples of Shankleesh and 83 of Kishk) were collected from the Bekaa Valley in the Northeast region of Lebanon. Suspected Listeria colonies were selected and initially identified by using standard biochemical tests. Initial identification of the positive L. monocytogenes colonies was confirmed at the molecular level by Polymerase Chain Reaction (n=30) and the confirmed isolates were evaluated for their susceptibility to 10 commonly used antimicrobials. All of the 30 isolates were confirmed to be L. monocytogenes yielding a PCR product of approximately 660 base pairs (bp). L. monocytogenes was detected in 26.67%, 13.89% and 7.23% of the Baladi cheese, Shankleesh and Kishk samples, respectively. The highest resistance in L. monocytogenes isolates was noted against oxacillin (93.33%) followed by penicillin (90%). The results provide an indication of the contamination levels of dairy-based foods in Lebanon and highlight the emergence of multi-drug resistant Listeria in the environment.

Ticks (Ixodidae) and other ectoparasites in Ulu Muda Forest Reserve, Kedah, Malaysia

A survey of ticks and other ectoparasites was carried out during a national biodiversity scientific expedition at Ulu Muda Forest Reserve, Kedah, Malaysia from 23-29 March 2003. A total of 161 animals comprising 20 species of birds, 16 species of bats, six species of non-volant small mammals and 12 species of reptiles were examined for ticks and other ectoparasites. From these animals, nine species in five genera of ticks, 10 species in two families of Mesostigmatid mites and five species of chiggers were collected. Three of the ectoparasitic species found, Dermacentor auratus, Ixodes granulatus and Leptotrombidium deliense are of known public health importance. This survey produced the first list of ticks and other ectoparasites in the forest reserve and the third study of ectoparasites in Kedah. Fourteen species of these ectoparasites are new locality records.

A survey of ectoparasites in Gunung Stong Forest Reserve, Kelantan, Malaysia

A survey of ticks and other ectoparasites was carried out during a national biodiversity scientific expedition at Gunung Stong Forest Reserve, Kelantan, Malaysia from 23-29 May 2003. A total of 272 animals comprised of 12 species of birds, 21 species of bats, 7 species of rodents and 2 species of insects were examined for ticks and other ectoparasites. From these animals, 5 species in 4 genera of ticks; 7 species in 2 families of Mesostigmatid mites and 5 species of chiggers were collected. Among the ectoparasites found were Ixodes granulatus and Leptotrombidium deliense, which are of known medical importance. A tick island consisting of 10 nymphal stages of Dermacentor spp was observed feeding on Rattus tiomanicus.

Laboratory evaluation of five pesticides for control of Leptotrombidium fletcheri (Acari: Trombiculidae)

Five pesticides were evaluated against laboratory colonies of Leptotrombidium fletcheri (Womersly and Heaslip) by the Pasteur pipet technique. The pesticides were dieldrin (LC50 = 3.6 ppm, LC99 = 18.2 ppm), bromopropylate (LC50 = 9.2 ppm, LC99 = 239.6 ppm), dicofol (LC50 = 27.8 ppm, LC99 = 118.1 ppm), fenthion (LC50 = 15.4 ppm, LC99 = 29.7 ppm), and malathion (LC50 = 84.7 ppm, LC99 = 313.9 ppm). Dieldrin was the most toxic. Dicofol was recommended for further evaluation in field trials.

Postpartum spontaneous rupture of ovarian artery aneurysm

A case of spontaneous rupture of a right ovarian artery aneurysm after delivery is presented. Search of the literature revealed 3 similar cases of spontaneous rupture during early peurperium and 1 case of spontaneous rupture of an ovarian artery on the third postpartum day with no abnormal findings of the vessel at the site of rupture.