Rapid emergence of antibacterial resistance by bacterial isolates from patients of gynecological infections in Punjab, Pakistan

Recent Developments in the Inhibition of Bacterial Adhesion as Promising Anti-Virulence Strategy

Infectious diseases caused by antimicrobial-resistant strains have become a serious threat to global health, with a high social and economic impact. Multi-resistant bacteria exhibit various mechanisms at both the cellular and microbial community levels. Among the different strategies proposed to fight antibiotic resistance, we reckon that the inhibition of bacterial adhesion to host surfaces represents one of the most valid approaches, since it hampers bacterial virulence without affecting cell viability. Many different structures and biomolecules involved in the adhesion of Gram-positive and Gram-negative pathogens can be considered valuable targets for the development of promising tools to enrich our arsenal against pathogens.

Antimicrobial Resistance of Escherichia coli From Aquaculture Farms and Their Environment in Zhanjiang, China

Antimicrobial resistance (AMR) has become a major concern worldwide. To evaluate the AMR of Escherichia coli in aquaculture farms of Zhanjiang, China, a total of 90 samples from the water, soil, and sediment of three aquaculture farms (farms I, II, and III) in Zhanjiang were collected, and 90 strains of E. coli were isolated for drug resistance analysis and AMR gene detection. The results indicated that the isolated 90 strains of E. coli have high resistance rates to penicillin, amoxicillin, ampicillin, tetracycline, compound sulfamethoxazole, sulfisoxazole, chloramphenicol, florfenicol, and rifampin (≥70%). Among these antimicrobial drugs, the resistance rate to rifampicin is as high as 100%. Among the isolated 90 strains of E. coli, all of them were resistant to more than two kinds of antimicrobial drugs, the number of strains resistant to nine kinds of drugs was the largest (19 strains), and the most resistant strain showed resistance to 16 kinds of antibacterial drugs. Regarding the AMR genes, among the three aquaculture farms, the most resistance genes were detected in farm II (28 species). The detection rate of bla_TEM, bla_CIT, bla_NDM, floR, OptrA, cmlA, aphA1, Sul2, oqxA, and qnrS in 90 isolates of E. coli was high (≥50%). The detection rate of carbapenem-resistant genes, such as bla_KPC, bla_IMP, and cfr, was relatively lower ( ≤ 30%), and the detection rate of mcr2 was the lowest (0). At least four AMR genes were detected for each strain, and 15 AMR genes were detected at most. Among them, the number of strains that carried 10 AMR genes was the largest (15 strains). Finally, a correlation analysis found that the AMR genes including bla_TEM, bla_CIT, floR, OptrA, cmlA, aac(3)-II, Sul2, ereA, ermB, oqxB, qnrA, mcr1, and mcr2 had a high correlation rate with drug resistance (≥50%). To summarize, the 90 strains of E. coli isolated from water, surrounding soil, and sediment samples showed resistance to multi-antimicrobial drugs and carried various antimicrobial resistance genes. Thus, it is essential to strengthen the rational use of antimicrobial drugs, especially the amide alcohol drugs, and control the AMR in the aquaculture industry of Zhanjiang, China.

Phytochemical content and potential health applications of pecan [Carya illinoinensis (Wangenh) K. Koch] nutshell

BACKGROUND

The pecan nutshell contains phytochemicals with various biological activities that are potentially useful in the prevention or treatment of diseases such as cancer, diabetes, and metabolic imbalances associated with heart diseases.

OBJECTIVE

To update this topic by means of a literature review and include those that contribute to the knowledge of the chemical composition and biological activities of pecan nutshell, particularly of those related to the therapeutic potential against some chronic degenerative diseases associated with oxidative stress.

METHOD

Exhaustive and detailed review of the existing literature using electronic databases.

CONCLUSION

The pecan nutshell is a promising natural product with pharmaceutical uses in various diseases. However, additional research related to the assessment of efficient extraction methods and characterization, particularly the evaluation of the mechanisms of action in new in vivo models, is necessary to confirm these findings and development of new drugs with therapeutic use.

In silico study and biological screening of benzoquinazolines as potential antimicrobial agents against methicillin-resistant Staphylococcus aureus, carbapenem-resistant Klebsiella pneumoniae, and fluconazole-resistant Candida albicans

Globally, antibiotic-resistant pathogens have become a serious threat to public health. The use of drugs having structures different from those applied in the clinical treatments of bacterial infections is a well-known potential solution to the antibiotic resistance crisis. Benzo-[g]-quinazolines were identified by our research group as a new class of antimicrobial agents. Herein, to follow-up the research on such compounds, three benzo-[g]-quinazolines (1-3) were studied, as in vitro antibacterial candidates against methicillin-resistant Staphylococcus aureus (MRSA), carbapenem-resistant Klebsiella pneumoniae, and fluconazole-resistant Candida albicans, as well. The minimum inhibitory concentration (MIC) assay for benzoquinazolines was carried out via the calorimetric broth microdilution method using the XTT assay in comparison with vancomycin, ciprofloxacin, and ketoconazole as reference drugs. The target compounds 1-3 revealed high variation in their activity against the examined resistant microbial strains. Benzoquinazoline 3 exhibited a more potent effect against the resistant strains compared with the reference drugs. A docking study was performed to identify the interactions between the benzoquinazolines 1-3 and ligand proteins (OXA-48 carbapenemase, β-lactamase, and sterol 14-alpha demethylase (CYP51)) at the active sites. Benzoquinazolines 1-3 showed very weak cytotoxicity against human lung fibroblast normal cells (WI-38). The targets showed promising antimicrobial effects against the three resistant strains. These findings may inform future inhibitor discoveries targeting penicillin-binding proteins.

Phytochemicals: A Promising Weapon in the Arsenal against Antibiotic-Resistant Bacteria

The extensive usage of antibiotics and the rapid emergence of antimicrobial-resistant microbes (AMR) are becoming important global public health issues. Many solutions to these problems have been proposed, including developing alternative compounds with antimicrobial activities, managing existing antimicrobials, and rapidly detecting AMR pathogens. Among all of them, employing alternative compounds such as phytochemicals alone or in combination with other antibacterial agents appears to be both an effective and safe strategy for battling against these pathogens. The present review summarizes the scientific evidence on the biochemical, pharmacological, and clinical aspects of phytochemicals used to treat microbial pathogenesis. A wide range of commercial products are currently available on the market. Their well-documented clinical efficacy suggests that phytomedicines are valuable sources of new types of antimicrobial agents for future use. Innovative approaches and methodologies for identifying plant-derived products effective against AMR are also proposed in this review.

Sortase A (SrtA) inhibitors as an alternative treatment for superbug infections

Virulence factor, sortase A (SrtA), has crucial roles in the pathogenesis of Gram-positive superbugs. SrtA is a bacterial cell membrane enzyme that anchors crucial virulence factors to the cell wall surface of Gram-positive bacteria. SrtA is not necessary for bacterial growth and viability and is conveniently accessible in the cell membrane; therefore, it is an ideal target for antivirulence drug development. In this review, we focus on antimicrobial resistance (AMR)-expressing bacteria and SrtA as a potential target for overcoming AMR. The mechanism of action of SrtA and its inhibition by various types of inhibitors, such as synthetic small molecules, peptides, and natural products, are provided. Future SrtA research perspectives for alternative drug development to antibiotics are also proposed.

Rising prevalence of multidrug-resistant uropathogenic bacteria from urinary tract infections in pregnant women

Objectives

This study aimed to determine the prevalence of urinary tract infections (UTI) in pregnant women and characterise the uropathogenic bacterial strains associated with symptomatic and asymptomatic bacteriuria in Lahore, Pakistan.

Methods

Between December 2018 and June 2019, we analysed the uropathogenic bacterial strains from midstream urine samples in 80 pregnant women. The age of the pregnant women ranged from 19 to 45 years, and they resided in urban and rural areas. We also recorded socioeconomic factors in this cohort. The isolated strains were phenotypically identified and evaluated for multiple drug resistance (MDR) patterns against recommended antimicrobial drugs.

Results

Of the 80 pregnant women, 65 had UTI, reflecting an 81% prevalence of UTI in women during pregnancy. The majority of participants aged 24–35 years, were multipara, and were in their third trimester. Results showed that 67 uropathogenic bacterial strains belonged to Escherichia (31%), Klebsiella (23%), Pseudomonas (16%), Streptococcus (4%), Enterococcus (4%), Staphylococcus (4%), and Proteus (3%) genera, as identified using biochemical characterisation. The highest overall resistance of Escherichia was seen against amoxicillin, pipemidic acid, and ampicillin; for Klebsiella against pipemidic acid, ampicillin, and cefotaxime; and for Pseudomonas against ciprofloxacin and cefotaxime. The three strains with the highest MDR were identified using 16S rRNA as Pseudomonas aeruginosa strain UA17, Escherichia coli strain UA32, and Klebsiella pneumoniae strain UA47.

Conclusion

In this study, the MDR uropathogenic strains showed the highest resistance pattern. The alarming signs of MDR uropathogenic infections are infrequently addressed and thus, urgent attention to this matter is essential.