Different Classes Of Antibiotics Research Articles

Structure and function response of bacterial communities towards antibiotic contamination in hyporheic zone sediments

Bacterial communities are crucial for processing and degrading contaminants in hyporheic zones (HZ). However, the effects of antibiotics on HZ bacterial communities have seldom been addressed. Here, using MiSeq 16S amplicon sequencing technology, the effects of acute exposure to Enrofloxacin, Sulfathiazole, Tetracycline hydrochloride, and Penicillin V potassium on HZ bacterial communities were investigated. Results revealed that HZ sediment communities responded differently to different classes of antibiotics, reflecting the distinct selection stress of antibiotics on HZ bacterial communities. Besides, HZ communities from the locations with more severe antibiotic contamination backgrounds (∼150 μg kg−1) were more resistant towards antibiotic treatment. Compared with small/non-significant changes in HZ community diversity and composition treated with ng L−1∼ug L−1 level antibiotics compared to the control group, treatments with antibiotics over mg L−1 level significantly reduced the diversity and changed the structures of HZ bacterial communities, and enhanced the resistance of the community to antibiotics by enriching antibiotic resistant bacteria. The exposure to mg L−1 level antibiotics also changed community functions by restricting the growth of functional bacteria, such as ammonia oxidizing bacteria (AOB) Nitrosomonas, resulting in ammonia accumulation in sediments. The results implied that at field-relevant concentrations, there was no or minor effect of antibiotics on HZ bacterial community structure and functions, and only those areas with high antibiotic concentrations would have effects.

Changing Paradigms in Antibiotic Resistance in Salmonella Species with Focus on Fluoroquinolone Resistance: A 5-Year Retrospective Study of Enteric Fever in a Tertiary Care Hospital in Kolkata, India.

Enteric fever, a potentially fatal multisystem disease that is caused by Salmonella enterica serovar Typhi and Paratyphi, poses a significant risk in low- and middle-income countries. A retrospective study to understand the prevalence and evolving patterns of antibiotic resistance in Salmonella Typhi and Paratyphi was undertaken from June 2017 to June 2022. A total of 4051 blood samples were collected from patients attending inpatient and outpatient departments of the School of Tropical Medicine (Kolkata, India) hospital. Blood samples were cultured, and culture positive samples were further processed for identification using conventional and automated systems. Antibiotic susceptibility test was performed using both the Kirby-Bauer disc diffusion method and VITEK2 (bioMerieux). Forty-five (1.1%) Salmonella species were isolated among the number of total (n = 4051) samples that were tested. Out of the 45 Salmonella isolates, 35 were Salmonella Typhi (77.77%) and 10 were Salmonella Paratyphi A (22.23%). We found pronounced fluoroquinolone resistance of 100% in the recent years (2019–2022) in both of the S. Typhi and S. Paratyphi A isolates. We found that 1 Salmonella Typhi and 2 Salmonella Paratyphi A isolates were resistant against multiple antibiotics (cefixime, ceftriaxone, ciprofloxacin and nalidixic acid), and 1 multidrug-resistant (MDR) Salmonella Paratyphi A isolate was found in a recent study year (2020) and it showed resistance against different classes of antibiotics (cephalosporins, fluoroquinolones and carbapenems). There was no resistance that was detected to the 3rd generation cephalosporins in the final years of the study. The emergence of Salmonella isolates that are resistant to multiple antibiotics poses a serious health problem. The antimicrobial resistance patterns that were detected in the study thus warrant further studies to understand the antibiotic susceptibility and resistance pattern of Salmonella against the major classes of antibiotics.

The Emergence of the Genus Comamonas as Important Opportunistic Pathogens.

Comamonas spp. are non-fermenting Gram-negative bacilli. They were first discovered in 1894, and since then, twenty-four species have been characterized. The natural habitat of these bacteria is soil, wastewater/sludge, fresh water such as ponds and rivers, and the animal intestinal microbiome. They were also isolated from industrial settings, such as activated sludge and polluted soil, and from the hospital environment and clinical samples, such as urine, pus, blood, feces, and kidney. Comamonas spp. are associated with environmental bioremediation and are considered an important environmental bacterium rather than a human pathogen. However, in the 1980s, they became a concern when several human infections associated with these species were reported. Here, the Comamonas genus was examined in terms of its members, identification techniques, and pathogenicity. Seventy-seven infection cases associated with these microorganisms that have been discussed in the literature were identified and investigated in this project. All relevant information regarding year of infection, country of origin, patient information such as age, sex, underlying medical conditions if any, type of infection caused by the Comamonas species, antibiotic susceptibility testing, treatment, and outcomes for the patient were extracted from case reports. The findings suggest that even though Comamonas spp. are thought of as being of low virulence, they have caused harmful health conditions in many healthy individuals and even death in patients with underlying conditions. Antimicrobial treatment of infections associated with these species, in general, was not very difficult; however, it can become an issue in the future because some strains are already resistant to different classes of antibiotics. Therefore, these pathogens should be considered of such importance that they should be included in the hospital screening programs.

Assessment of antibiotic storage practices, knowledge, and awareness related to antibiotic uses and antibiotic resistance among household members in post-conflict areas of Pakistan: Bi-central study.

BackgroundThe storage of antimicrobials at home is frequently in-practice in various developing countries, resulting an irrational use, antibiotic resistance, and toxicities. This condition may worsen more in conflict zones where health facilities are limited. This study aimed to determine the storage and use of leftover antibiotics among households (HHs) along with knowledge and awareness about antibiotics and antibiotic resistance (ABR).MethodsA descriptive cross-sectional study design was employed. Members of HHs were invited to participate in the survey while using a convenient sampling technique. The data were obtained using a validated questionnaire and analyzed through SPSS.ResultsA total of 96 HHs were randomly selected from two districts (n = 50, n = 46), with most of the participants being men between the ages of 18 and 28 (n = 45, 46.9%) years. The majority of HHs (n = 32, 33.3%) had six to eight total family members, with one to two chronic diseases (n = 63, 65.6%), individual families (n = 60, 62.5%), and with (n = 35, 36.5%) LRTIs (lower respiratory tract infections). The HHs were aware of the word “antibiotic” (n = 59, 61.5%) and gave correct replies to amoxicillin as an antibiotic (n = 42, 43.8%); on the other hand, HHs also thought of paracetamol as an antibiotic (n = 45, 47.9%). They identified the most common brands of antibiotics easily, and a majority of them (n = 69, 71.9%) had never heard of ABR before and had lower levels of awareness. The most stored antibiotic at home (n=38, 39.6%) was azithromycin (J01FA10). In addition, they had multiple needless (1–2, n = 62, 64.6%; 3–4, n = 29, 30.2%) and antibiotics in their houses. Age had a strong association (p = 0.017, H = 12) affected the mean knowledge scores related to antibiotic use. Association of education levels (p = 0.001, H = 52.8) and occupation (p = 0.04, H = 10) with proper antibiotics use were found to be significant. However, family members with more than one chronic illness (p = 0.09, H = 0.8) showed a significant relationship with their awareness of antibiotics.ConclusionParticipants generally stored various antibiotics of different classes in their homes. Lack of knowledge related to the appropriate usage of antibiotics, use of leftover antibiotics, and awareness related to ABR were unknown to the participants.

Simulated Micro-, Lunar, and Martian Gravities on Earth-Effects on Escherichia coli Growth, Phenotype, and Sensitivity to Antibiotics.

Bacterial behavior has been studied under microgravity conditions, but very little is known about it under lunar and Martian gravitational regimes. An Earth-based approach was designed and implemented using inclined clinostats and an in-house-developed code to determine the optimal clinorotation angular speed for bacterial liquid cultures of 5 RPM. With this setup, growth dynamics, phenotypic changes, and sensitivity to antibiotics (minimum inhibitory concentration (MIC) of two different classes of antibiotics) for three Escherichia coli strains (including uropathogenic) were examined under simulated micro-, lunar, and Martian gravities. The results included increased growth under simulated micro- and lunar gravities for some strains, and higher concentrations of antibiotics needed under simulated lunar gravity with respect to simulated micro- and Martian gravities. Clinostat-produced results can be considered suggestive but not determinative of what might be expected in altered gravity, as there is still a need to systematically verify these simulation devices’ ability to accurately replicate phenomena observed in space. Nevertheless, this approach serves as a baseline to start interrogating key cellular and molecular aspects relevant to microbial processes on the lunar and Martian surfaces.

Clostridioides difficile Infection in Children-An Update.

Clostridioides difficile Infection in Children-An Update.

Clinicoradiological correlation of Endotracheal secretion culture in each case of suspected VAP: a need of the present to combat drug-resistance

Background: Ventilator-associated pneumonia (VAP) in intensive care unit (ICU)-admitted patients is a life-threatening event, caused by a diverse range of microbes having varied susceptibility to different classes of antibiotics. Materials and Methods: We enrolled patients admitted in trauma ICU on mechanical ventilation for >48 h. Modified clinical pulmonary infection score (≥6) having a significant bacterial count (≥105 cfu/ml) in endotracheal (ET) secretions was used to diagnose VAP. Subsequently, we did antibiotic susceptibility testing by the modified Kirby–Bauer method, and the results were interpreted per Clinical and Laboratory Standards Institute guidelines. Results: We enrolled 389 patients in this study. Amongst these, we noted VAP events in 87 patients with an incidence of 15.62/1000 days of ventilators. Gram-negative rods were the predominant microbes causing VAP. Acinetobacter baumannii-calcoaceticus complex (n = 30) followed by Klebsiella pneumoniae (n = 27) and Pseudomonas aeruginosa (n = 19) was the predominant isolate. All nine isolated Staphylococcus aureus strains were methicillin-resistant S. aureus (MRSA). About 48.72% (38/78) of the Gram-negative microbes were meropenem sensitive. All strains of A. baumanii and P. aeruginosa were sensitive to polymyxin B, whereas all isolated MRSA strains were sensitive to vancomycin and linezolid. In addition, drug-resistant epidemiological important bacterial pathogens were also isolated from ET secretions. Conclusion: VAP is caused by a diverse group of multidrug-resistant microorganisms; however, drug-resistant microbes also colonise the in situ ET tubes. Therefore, accurate diagnosis of VAP and its differentiation from ET tube colonisation is a need of present times as appropriate treatment of actual VAP cases will reduce the burden of drug-resistant microbes in ICU settings.

ANTIBIOTIC RESISTANCE PATTERN OF BACTERIAL PATHOGENS ISOLATED FROM PUS IN A TERTIARY CARE HOSPITAL OF CENTRAL INDIA

Pyogenic infections are commonly caused by various microorganisms and mixed infections that require antibiotic therapy. Emergence of antimicrobial drug resistance among susceptible individuals due to injudicious use of antibiotics has made the treatment of wound infections very difcult. This study was undertaken to determine the antibiotic resistance pattern among aerobic bacteria isolated from pus samples. A total of 312 pus samples were received in the Department of Microbiology, GMCH Nagpur from January to March 2021. The pus isolates were identied and processed by standard bacteriological techniques. The Antimicrobial Susceptibility Testing (AST) was performed by Kirby-Bauer disc diffusion technique and the drugs used were in accordance with Clinical and Laboratory Standards Institute (CLSI) guidelines 2020.Out of total 312 pus samples, 182 (58.33%) yielded signicant bacterial growth. The most prevalent pathogen isolated were Klebsiella pneumoniae 60 (19.23%) followed by Escherichia coli 42 (13.46%). Further, the study shows that Methicillin Resistant Staphylococcus Aureus (MRSA) and Inducible Clindamycin Resistance (ICR) were 29.41% and 11.76% respectively; moreover 70% isolates were Multi Drug Resistant (MDR). Therefore, this study indicates the prevalence of resistance to different classes of antibiotics in bacterial isolates and highlights the need for effective surveillance, regular reporting and antibiogram-guided antibiotic prescription.

Prospective study for utilization review for multiple antibiotics prescribed in the specialty department in tertiary care teaching hospital

<p><strong>Background:</strong> The aim of the work was a prospective study of utilization review for multiple antibiotics prescribed in the specialty department in a tertiary care teaching hospital.</p><p><strong>Methods: </strong>A prospective study was conducted for 6 months in specialty department in a tertiary care teaching hospital.</p><p><strong>Results: </strong>In the 6 months duration of the study, a total number of 96 prescriptions were analyzed. The 77 prescriptions were prescribed with Beta-lactam antibiotics. and remaining prescriptions were prescribed with 2, 3 and 4-5 different classes of antibiotics.</p><p><strong>Conclusions: </strong>The result obtained from our study is for judgment use of antibiotics will reduce the burden of multi-drug resistance and thereby enable better patient management and limit patient morbidity and mortality.<strong></strong></p>

Antibiotic Consumption Patterns in European Countries Are Associated with the Prevalence of Parkinson's Disease; the Possible Augmenting Role of the Narrow-Spectrum Penicillin.

Parkinson’s disease: Parkinson’s disease (PD) is the second-most common neurodegenerative disease, affecting at least 0.3% of the worldwide population and over 3% of those over 80 years old. According to recent research (2018), in 2016, 6.1 million (95% uncertainty interval (UI) 5.0–7.3) individuals had Parkinson’s disease globally, compared with 2.5 million (2.0–3.0) in 1990. The pandemic-like spreading of PD is considered a slow-moving disaster. Most recent studies indicated the possible role of an altered microbiome, dysbiosis, in the development of PD, which occurs long before the clinical diagnosis of PD. Antibiotics are considered as major disruptors of the intestinal flora and we have hypothesized that, as different classes of antibiotics might induce different dysbiosis, certain classes of antibiotics could trigger the PD-related dysbiosis as well. Comparative analyses were performed between the average yearly antibiotic consumption of 30 European countries (1997–2016) and the PD prevalence database (estimated for 2016). We divided the time frame of antibiotic consumption of 1997–2016 into four subsections to estimate the possible time lapse between antibiotic exposure and the prevalence, prevalence change, and PD-related death rates estimated for 2016. Our results indicated that countries with high consumption of narrow-spectrum penicillin experienced a higher increase in PD prevalence than the others. Countries reporting a decline in PD from 1990 to 2016 demonstrated a reduction in the consumption of narrow-spectrum penicillin in this period.

A water-stable zwitterionic Zn(II) coordination polymer as a luminescent sensor for the nitrofurazone antibiotic in milk

The abuse of antibiotics has become a global problem because it has caused many serious environmental problems and threatened human health. Therefore, the selective and sensitive detection of antibiotic residues is important. In this work, a novel coordination polymer, {[ZnL1.5(H2O)]·(ClO4)2·3H2O} (CP 1), was constructed under hydrothermal conditions using a zwitterionic organic ligand (1,1′(2,3,5,6-tetramethyl-1,4-phenylene)bis(methylene)bis(4- carboxypyridin-1-ium)chloride (H2LCl2)). CP 1 was characterized by single-crystal X-ray diffraction, powder X-ray diffraction, FT-IR spectroscopy, elemental analysis and thermal gravimetric analysis. Among the different classes of antibiotics, CP 1 can selectively and efficiently recognize the nitrofurazone (NZF) antibiotic with low limit of detection (0.012 μM). CP 1 showed good selectively, strong anti-interference and powerful recyclability in the detection of the NZF antibiotic. As a sensitive sensor, CP 1 can detect NZF in milk, and a perfect recovery (97.40 %–103.05 %) was acquired. Additionally, the fluorescence quenching mechanism was attributed to fluorescence resonance energy transfer and photoinduced electron transfer.

Management of clinical infections of Escherichia coli by new β-lactam/β-lactamase inhibitor combinations.

Escherichia coli (E. coli) is an important member of Enterobacteriaceae family involved in severe infections. The increased rate of resistance towards different classes of antibiotics limits their treatment options. The aim of this study was to assess the in vitro activity of classical and novel combinations of β-lactam/β-lactamase inhibitor against E. coli clinical isolates. 140 clinical isolates of E. coli were collected from clinical specimens from Gastrointestinal Surgery Center (GISC) in Egypt. Extended spectrum β-lactamase (ESBL) was detected by double disk synergy test. Furthermore, the minimum inhibitory concentrations (MICs) for five different combinations were determined using the broth microdilution method including: amoxicillin/clavulanate and ampicillin/sulbactam as an example for classical combinations and cefoperazone/sulbactam, ceftazidime/avibactam, and cefepime/enmetazobactam as an example for new combinations. The percentage of ESBL production among the tested isolates was 46.4%. Isolates were highly resistant to classical β-lactam/β-lactamase inhibitor combinations, where (40.7%) and (42.9%) of isolates were resistant to amoxicillin/clavulanate and ampicillin/sulbactam, respectively. While new β-lactam/β-lactamase inhibitor combinations had promising inhibitory action. The addition of novel β-lactamase inhibitors restored the susceptibility of isolates, where (94.3%) of isolates became susceptible to ceftazidime/avibactam combination, followed by cefoperazone/sulbactam (89.2%) and cefepime/enmetazobactam (85.7%). The synergistic effect seems to be effective where ceftazidime and avibactam were synergistic in 80% of isolates. The antibacterial activity of some antimicrobial agents can be enhanced by the addition of new β-lactamase inhibitors. Further in vivo investigation is needed to confirm their therapeutic efficacy against local isolates.

Prevalence of Plasmid-Mediated Quinolone Resistance (PMQRs) Determinants and Whole Genome Sequence Screening of PMQR-Producing E. coli Isolated from Men Undergoing a Transrectal Prostate Biopsy.

Fluoroquinolones (FQs) are recommended as prophylaxis for men undergoing transrectal prostate biopsy (TRUS-Bx). Recent studies suggest a significant share of FQ-resistant rectal flora in post-TRUST-Bx infections. Methods: 435 Enterobacterales isolates from 621 patients attending 12 urological departments in Poland were screened by PCR for PMQR genes. PMQR-positive isolates were tested for quinolone susceptibility and investigated by whole genome sequencing (WGS) methods. Results: In total, 32 (7.35%) E. coli strains with ciprofloxacin MIC in the range 0.125–32 mg/L harbored at least one PMQR gene. qnrS and qnrB were the most frequent genes detected in 16 and 12 isolates, respectively. WGS was performed for 28 of 32 PMQR-producing strains. A variety of serotypes and sequence types (STs) of E. coli was noticed. All strains carried at least one virulence gene. AMR genes that encoded resistance against different classes of antibiotics were identified. Additionally, five of 13 ciprofloxacin-susceptible E. coli had alterations in codon 83 of the GyrA subunits. Conclusion: This study provides information on the common presence of PMQRs among E. coli, which may explain the cause for development of post-TRUS-Bx infections. High numbers of virulence and antimicrobial resistance genes detected show a potential for analysed strains to develop infections.

Characterization of Sequence Types and Mechanisms of Resistance to Tigecycline Among Acinetobacter baumannii Isolated from Children.

The present study aimed to investigate the mechanisms of resistance to tigecycline and to determine sequence types of Acinetobacter baumannii isolates recovered from children, using the Multilocus Sequence Typing (MLST). A total of 74 A. baumannii isolates were recovered from patients at one of the children's hospital in Tehran, Iran. Antimicrobial susceptibility testing of the isolates was performed for different classes of antibiotics and minimum inhibitory concentrations of colistin and tigecycline were determined using broth microdilution method and E-test strips, respectively. The presence of ISAba1, AbaR, tet(39), and tetX and the expressions of adeB, adeG, and adeJ efflux pump genes were measured using Polymerase Chain Reaction (PCR) and quantitative real-time PCR (RT-PCR), respectively. The diversity of mutations across the regulatory genes of RND efflux pumps (adeRS, adeL, and adeN) and trm gene were determined using their PCR amplification and DNA sequencing in tigecycline-resistant isolates. In addition, STs of tigecycline-resistant isolates were determined using MLST method. Three A. baumannii isolates were resistant to tigecycline. Several amino acid substitutions were identified in AdeRS, AdeN, and Trm but no alteration was found in AdeL. Nevertheless, adeB, adeG, and adeJ overexpression were observed in 1, 2, and 1 isolates, respectively. The tigecycline-resistant isolates belonged to ST1720 and ST2285. This is the first study reporting on ST2285 in A. baumannii populations. Among 74 isolates, two tigecycline susceptible isolates carried tet(39) gene but no tetX gene was detected. We concluded that mutations in regulatory genes of RND efflux pumps and the trm gene may play some important role in A. baumannii resistance to tigecycline.

Studies on photocatalytic removal of antibiotics, ciprofloxacin and sulfamethoxazole, by Fe3O4-ZnO-Chitosan/Alginate nanocomposite in aqueous systems

An ultraviolet-light-induced antibiotic degradation system based on nano-ZnO and Fe3O4 and chitosan/alginate nanocomposite bead assembly has been developed using a facile green-synthesis approach. In this study Camellia sinensis extract was used as reducing agent to facilitate the formation of the nanoparticles. The Fe3O4-ZnO-CS/SA nanocomposite was employed to degrade ciprofloxacin (CIP) and sulfamethoxazole (SMX) under UV-C light irradiation, and 94.77% and 93.31% degradation was achieved respectively within 180 min with the optimized conditions [pH of 4.0, antibiotic concentration of 10 mg/L, and Fe3O4-ZnO-CS/SA nanocomposite weight of 10 g and 15 g for CIP and SMX respectively]. For both the antibiotics, the pseudo-first-order model fitted well with the reaction kinetics data, while the Langmuir isotherm model showed a better fit compared to the Freundlich and Temkin models. Analyzing various characterization data reaction mechanism for CIP and SMX degradation was proposed. In addition, possible degradation pathways of CIP and SMX were proposed based on the intermediates detected by HR-LCMS analysis. Furthermore, the trapping experiments showed that superoxide (1O2) and hydroxyl (OH) radicals play major role in the photodegradation of CIP and SMX. The effects of ionic strength, natural organics and various natural water systems on degradation efficacy was investigated. The degraded products were found to show less toxicity to a model organism, a fresh water alga, compared to the parent compounds. This work provides a simple strategy to integrate CS/SA with nano-ZnO and Fe3O4 to construct effective nanocomposite photocatalyst for the degradation of different classes of antibiotics.

Antimicrobial resistance in fish pathogens and alternative risk mitigation strategies

AbstractThe discovery of antimicrobial agents, particularly antibiotics, is one of the most important milestones in the history of therapeutics. Since their discovery, antibiotics have been widely used in human medicine, veterinary, agriculture and aquaculture sectors. Many of the antibiotics used in human and veterinary medicine are also being used in the aquaculture sector either for therapy or as prophylactic agents. However, there is increasing awareness and concern for the indiscriminate use of antibiotics and the consequent emergence of antimicrobial resistance in the aquaculture settings. An aquatic environment, especially if it is eutrophic, provides a suitable niche for many bacterial pathogens to survive and multiply. Although there are limited reports of large‐scale outbreaks in the aquaculture sector directly caused by antibiotic resistant fish pathogens, the presence of transferable plasmids, transposons and integrons in fish pathogens such as Aeromonas spp., Edwardsiella spp. and Vibrio spp. is a cause of concern. Thus, the need to study the resistance determinants found in these transmissible elements to different classes of antibiotics carried by fish pathogens and, their dissemination is highly relevant.

Whole-Genome Sequencing of ST2 A. baumannii Causing Bloodstream Infections in COVID-19 Patients.

A total of 43 A. baumannii strains, isolated from 43 patients affected by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and by bacterial sepsis, were analyzed by antimicrobial susceptibility testing. All strains were resistant to almost three different classes of antibiotics, including carbapenems and colistin. The whole-genome sequencing (WGS) of eight selected A. baumannii isolates showed the presence of different insertion sequences (ISs), such as ISAba13, ISAba26, IS26, ISVsa3, ISEc29, IS6100 and IS17, giving to A. baumannii a high ability to capture and mobilize antibiotic resistance genes. Resistance to carbapenems is mainly mediated by the presence of OXA-23, OXA-66 and OXA-82 oxacillinases belonging to OXA-51-like enzymes. The presence of AmpC cephalosporinase, ADC-25, was identified in all A. baumannii. The pathogenicity of A. baumannii was exacerbated by the presence of several virulence factors. The multi-locus sequence typing (MLST) analysis showed that all strains belong to sequence type 2 (ST) international clone.

Plant Alkylbenzenes and Terpenoids in the Form of Cyclodextrin Inclusion Complexes as Antibacterial Agents and Levofloxacin Synergists.

Allylpolyalkoxybenzenes (APABs) and terpenoids from plant essential oils exhibit a range of remarkable biological effects, including analgesic, antibacterial, anti-inflammatory, antioxidant, and others. Synergistic activity with antibiotics of different classes has been reported, with inhibition of P-glycoprotein and impairment of bacterial cell membrane claimed as probable mechanisms. Clearly, a more detailed understanding of APABs’ biological activity could help in the development of improved therapeutic options for a range of diseases. However, APABs’ poor solubility in water solutions has been a limiting factor for such research. Here, we found that complex formation with β-cyclodextrins (CD) is an efficient way to transform the APABs into a water-soluble form. Using a combination of spectroscopic (FTIR, NMR, UV) methods, we have estimated the binding constants, loading capacity, and the functional groups of both APABs and monoterpenes involved in complex formation with CD: ethylene, aromatic, methoxy and hydroxy groups. In the presence of a molar excess of CD (up to 5 fold) it was possible to achieve the complete dissolution of APABs and terpenoids in an aqueous medium (at 90–98% encapsulation) higher by 10–1000 times. Further, we have demonstrated that CD-APABs, if used in combination with levofloxacin (Lev), can be antagonistic, indifferent, additive, or synergistic, mostly depending on the concentration ratio: at high Lev concentration with the addition of APAB is typically neutral or even antagonistic; while at a Lev concentration below MIC, the addition of CD-APAB is either additive or synergistic (according to FICI criteria). An over three-fold increase in Lev antibacterial activity was observed in combination with eugenol (EG), as per the growth inhibition diameter measurement in agar. Interestingly, a synergistic effect could be observed with both Gram-positive and Gram-negative bacteria. So, obviously, the APAB-CD and terpenoid-CD mechanism of action is not limited to their interaction with the bacterial membrane, which has been shown earlier for CDs. Further research may open new prospects for the development of adjuvants to improve the therapeutic regimens with existing, as well as with new anti-infective drugs.

Draft genome analysis of a multidrug-resistant Pseudomonas aeruginosa CMPL223 from hospital wastewater in Dhaka, Bangladesh

Multidrug-resistant (MDR) clones of Pseudomonas aeruginosa can cause complicated infections in human. The emergence of ST664 of MDR P. aeruginosa has been reported in Nepal, Iran and China. Here, we present the draft genome analysis of a MDR P. aeruginosa CMPL223 isolated from hospital wastewater in Bangladesh to understand antimicrobial resistance trends and pathogenicity. Cetrimide agar was used for isolation of P. aeruginosa. Polymerase chain reaction (PCR) was carried out for detection of biofilm and integron related genes. Bacterial susceptibility to antibiotics was determined by disc diffusion method. Sequencing of whole genomic DNA was performed using Illumina iSeq 100 platform. Following quality checking of raw reads, assembly and annotation of sequences, a wide array of in silico tools were used for characterization of draft genome. The isolate was a strong biofilm former, carried integron 1 in chromosomal DNA, and was predicted to be pathogenic. It belongs to sequence type ST664 and O7 serogroup. The assembled genome contained 12 acquired antimicrobial resistant (AMR) genes, 2 prophage regions, 240 virulence genes, 71 drug targets, 142 insertion sequences, and 1 CRISPR (Clustered Regularly Interspaced Short Palindromic Repeats) array. The isolate was resistant to 21 out of 23 antibiotics, except colistin and imipenem. Comprehensive Antibiotic Resistance Database and ResFinder revealed that bacteria harboured blaOXA-50, blaOXA-796, blaPDC-374, fosA, tet(G), sul1, catB7, aph(3')-iib and ant(4')-IIb genes, conferring resistance to different classes of antibiotics. The results of in vitro characterization were consistent with the possible expression of detected antibiotic resistant genes through in silico analysis. Our data suggested the emergence of MDR P. aeruginosa ST664, which needs control measures for limiting its dissemination.

Anti-virulence therapeutic strategies against bacterial infections: recent advances.

The emergence and increasing prevalence of multidrug-resistant pathogens has become a major global healthcare problem. According to the World Health Organization if these trends continue, mortality from infection in 2050 will be higher than that from cancer. Microorganisms have various resistance mechanisms against different classes of antibiotics that emphasize the need for discovery of new antimicrobial compounds to treat bacterial infections. An interesting and new strategy for disarming pathogens is antivirulence therapy by blocking bacterial virulence factors or pathogenicity. Therefore, the use of these new pathoblockers could reduce the administration of broad-spectrum antimicrobials and prevalence of resistant strains. This review provides an overview of the antivirulence strategies published studies between years 2017 and 2021. Most antivirulence strategies focused on adhesins, toxins and bacterial communication. Additionally, targeting two-component systems and ncRNA elements were also examined in some studies. These new strategies have the potential to replace traditional antimicrobial agents and can be used to treat infections, especially infections caused by resistant pathogens, by targeting virulence factors.