Effect of a probiotic and an antibiotic on the mobilome of the porcine microbiota

Introduction: To consider the growing health issues caused by antibiotic resistance from a "one health" perspective, the contribution of meat production needs to be addressed. While antibiotic resistance is naturally present in microbial communities, the treatment of farm animals with antibiotics causes an increase in antibiotic resistance genes (ARG) in the gut microbiome. Pigs are among the most prevalent animals in agriculture; therefore, reducing the prevalence of antibiotic-resistant bacteria in the pig gut microbiome could reduce the spread of antibiotic resistance. Probiotics are often studied as a way to modulate the microbiome and are, therefore, an interesting way to potentially decrease antibiotic resistance. Methods: To assess the efficacy of a probiotic to reduce the prevalence of ARGs in the pig microbiome, six pigs received either treatment with antibiotics (tylvalosin), probiotics (Pediococcus acidilactici MA18/5M; Biopower® PA), or a combination of both. Their faeces and ileal digesta were collected and DNA was extracted for whole genome shotgun sequencing. The reads were compared with taxonomy and ARG databases to identify the taxa and resistance genes in the samples. Results: The results showed that the ARG profiles in the faeces of the antibiotic and combination treatments were similar, and both were different from the profiles of the probiotic treatment (p < 0.05). The effects of the treatments were different in the digesta and faeces. Many macrolide resistance genes were detected in a higher proportion in the microbiome of the pigs treated with antibiotics or the combination of probiotics and antibiotics. Resistance-carrying conjugative plasmids and horizontal transfer genes were also amplified in faeces samples for the antibiotic and combined treatments. There was no effect of treatment on the short chain fatty acid content in the digesta or the faeces. Conclusion: There is no positive effect of adding probiotics to an antibiotic treatment when these treatments are administered simultaneously.

Prevalence and Genomic Investigation of Salmonella Isolates Associated with Watermelons and Their Environmental Reservoirs in Bejaia, Algeria

This study was conducted in Bejaia, Algeria, to determine the presence of Salmonella in fresh watermelon (n = 105), soil (n = 23), and irrigation water samples (n = 17) collected from two different farms. After isolation, antimicrobial susceptibility testing, serotype determination, multilocus sequence typing, antimicrobial resistance genes detection, and whole genome sequencing were performed. Twenty watermelon samples (19%) were contaminated with Salmonella, but none were found in the soil or irrigation water. Among the 20 Salmonella isolates, 2 serovars were identified (Salmonella Liverpool and Salmonella Anatum), belonging to sequence types ST1959 and ST64, respectively. Ten Salmonella isolates showed significant resistance to nalidixic acid, ofloxacin, and ciprofloxacin but were susceptible to all other antibiotics. The coexistence of point mutations (parC:p.T57S) in Quinolone Resistance-Determining Regions and the qnrB19 gene may contribute to quinolone resistance. The study identified 164 virulence genes in the Salmonella isolates. Our study found Salmonella in fresh watermelon during the preharvest season in Bejaia, Algeria. Our study indicates a relatively high prevalence of Salmonella on watermelon samples before harvest. Although we cannot directly compare our results with previous studies, it is crucial to recognize that the absence of comprehensive comparative data underscores the need for further research and surveillance.

Antibiotic Resistance Trends Among Enterobacteriaceae in Saudi Arabia: A Systematic Review

Antibiotic resistance is a global public health concern that poses a significant threat to the effective treatment of bacterial infections. Enterobacteriaceae, a family of gram-negative bacteria, are associated with a wide range of infections, including urinary tract infections, bloodstream infections, and respiratory tract infections. This systematic review aimed to examine the antibiotic resistance trend among Enterobacteriaceae in Saudi Arabia in the period between 2003 and 2023. Five databases (PubMed, Medline, Ovid, Scopus, and Cochrane) were searched using the keywords "Resistance AND Enterobacteriaceae AND Saudi Arabia" in the title and abstract. All papers assessing the prevalence of resistance among Enterobacteriaceae in Saudi Arabia were included in the systematic review. Out of 97 papers that were extracted through the database search, 22 articles were considered suitable for the systematic review. The articles included 17027 Enterobacteriaceae isolates, out of which 7592 isolates were identified as resistant bacteria. The studies included various resistant strains, such as Escherichia coli and Klebsiella pneumoniae, that were responsible for various clinical conditions, including urinary tract infections, blood infections, surgical site infections, and pneumonia. In addition, the review highlighted the dynamic nature of antibiotic resistance, with the identification of new resistant bacterial species and the emergence of resistance to newer antibiotic classes over the last decade. Continued surveillance, rational antibiotic use, and the development of alternative treatment options are crucial to address the evolving landscape of antibiotic resistance among Enterobacteriaceae bacteria in the country.

Preventing E. coli Biofilm Formation with Antimicrobial Peptide-Functionalized Surface Coatings: Recognizing the Dependence on the Bacterial Binding Mode Using Live-Cell Microscopy

Antimicrobial peptides (AMPs) can kill bacteria by destabilizing their membranes, yet translating these molecules' properties into a covalently attached antibacterial coating is challenging. Rational design efforts are obstructed by the fact that standard microbiology methods are ill-designed for the evaluation of coatings, disclosing few details about why grafted AMPs function or do not function. It is particularly difficult to distinguish the influence of the AMP's molecular structure from other factors controlling the total exposure, including which type of bonds are formed between bacteria and the coating and how persistent these contacts are. Here, we combine label-free live-cell microscopy, microfluidics, and automated image analysis to study the response of surface-bound Escherichia coli challenged by the same small AMP either in solution or grafted to the surface through click chemistry. Initially after binding, the grafted AMPs inhibited bacterial growth more efficiently than did AMPs in solution. Yet, after 1 h, E. coli on the coated surfaces increased their expression of type-1 fimbriae, leading to a change in their binding mode, which diminished the coating's impact. The wealth of information obtained from continuously monitoring the growth, shape, and movements of single bacterial cells allowed us to elucidate and quantify the different factors determining the antibacterial efficacy of the grafted AMPs. We expect this approach to aid the design of elaborate antibacterial material coatings working by specific and selective actions, not limited to contact-killing. This technology is needed to support health care and food production in the postantibiotic era.

Polyphenols and their nanoformulations as potential antibiofilm agents against multidrug-resistant pathogens

The emergence of multidrug-resistant (MDR) pathogens is a major problem in the therapeutic management of infectious diseases. Among the bacterial resistance mechanisms is the development of an enveloped protein and polysaccharide-hydrated matrix called a biofilm. Polyphenolics have demonstrated beneficial antibacterial effects. Phenolic compounds mediate their antibiofilm effects via disruption of the bacterial membrane, deprivation of substrate, protein binding, binding to adhesion complex, viral fusion blockage and interactions with eukaryotic DNA. However, these compounds have limitations of chemical instability, low bioavailability, poor water solubility and short half-lives. Nanoformulations offer a promising solution to overcome these challenges by enhancing their antibacterial potential. This review summarizes the antibiofilm role of polyphenolics, their underlying mechanisms and their potential role as resistance-modifying agents.

Genomic islands and their role in fitness traits of two key sepsis-causing bacterial pathogens

To survive and establish a niche for themselves, bacteria constantly evolve. Toward that, they not only insert point mutations and promote illegitimate recombinations within their genomes but also insert pieces of 'foreign' deoxyribonucleic acid, which are commonly referred to as 'genomic islands' (GEIs). The GEIs come in several forms, structures and types, often providing a fitness advantage to the harboring bacterium. In pathogenic bacteria, some GEIs may enhance virulence, thus altering disease burden, morbidity and mortality. Hence, delineating (i) the GEIs framework, (ii) their encoded functions, (iii) the triggers that help them move, (iv) the mechanisms they exploit to move among bacteria and (v) identification of their natural reservoirs will aid in superior tackling of several bacterial diseases, including sepsis. Given the vast array of comparative genomics data, in this short review, we provide an overview of the GEIs, their types and the compositions therein, especially highlighting GEIs harbored by two important pathogens, viz. Acinetobacter baumannii and Klebsiella pneumoniae, which prominently trigger sepsis in low- and middle-income countries. Our efforts help shed some light on the challenges these pathogens pose when equipped with GEIs. We hope that this review will provoke intense research into understanding GEIs, the cues that drive their mobility across bacteria and the ways and means to prevent their transfer, especially across pathogenic bacteria.

Antibiotic Resistance and Genetic Profiles of Vibrio parahaemolyticus Isolated from Farmed Pacific White Shrimp (Litopenaeus vannamei) in Ningde Regions

To better understand the antibiotic resistance, virulence genes, and some related drug-resistance genes of Vibrio parahaemolyticus in farmed pacific white shrimp (Litopenaeus vannamei) in Ningde regions, Fujian province, we collected and isolated a total of 102 strains of V. parahaemolyticus from farmed pacific white shrimp in three different areas of Ningde in 2022. The Kirby-Bauer disk method was used to detect V. parahaemolyticus resistance to 22 antibiotics, and resistant genes (such as quinolones (qnrVC136, qnrVC457, qnrA), tetracyclines (tet A, tetM, tetB), sulfonamides (sulI, sulII, sulIII), aminoglycosides (strA, strB), phenicols (cat, optrA, floR, cfr), β-lactams (carB), and macrolides (erm)) were detected by using PCR. The findings in this study revealed that V. parahaemolyticus was most resistant to sulfamoxazole, rifampicin, and erythromycin, with resistance rates of 56.9%, 36.3%, and 33.3%, respectively. Flufenicol, chloramphenicol, and ofloxacin susceptibility rates were 97.1%, 94.1%, and 92.2%, respectively. In all, 46% of the bacteria tested positive for multi-drug resistance. The virulence gene test revealed that all bacteria lacked the tdh and trh genes. Furthermore, 91.84% and 52.04% of the isolates were largely mediated by cat and sulII, respectively, with less than 5% resistance to aminoglycosides and macrolides. There was a clear mismatch between the antimicrobial resistance phenotypes and genotypes, indicating the complexities of V. parahaemolyticus resistance.

Flankophile: a bioinformatic pipeline for prokaryotic genomic synteny analysis

IMPORTANCE

The Flankophile pipeline enables the analysis and visualization of flanking regions of prokaryotic sequences of interest on large data sets in one step and in a consistent manner. A specific tool for flanking region analysis with automated visualization has not been developed before, and Flankophile will make flanking region analysis easier and accessible to more people. Flankophile will be especially useful in the field of genomic epidemiology of acquired antimicrobial resistance genes. Here, information from flanking region sequences can be instrumental in rejecting or supporting the possibility of a recent common source of the same resistance gene found in different samples.

Synthesis and Antibacterial Activity of Mono- and Bi-Cationic Pyridinium 1,2,4-Oxadiazoles and Triazoles

One of the main causes of mortality in humans continues to be infectious diseases. Scientists are searching for new alternatives due to the fast increase in resistance of some harmful bacteria to the frontline antibiotics. To effectively treat pathogenic infections, it is crucial to design antibiotics that can prevent the development of pathogenic resistance. For this purpose, a set of 39 quaternary pyridinium and bis-pyridinium salts with different lengths of side alkyl or fluorinated chains, heterocyclic spacers, and counter ions were tested on diverse reference bacterial ATCC (American Type Culture Collection) strains, such as S. aureus and E. coli. Subsequently, 6 out of the 39 pyridinium salts showing relevant MIC (Minimum Inhibitory Concentration) values were tested on clinically isolated, resistant strains of S. aureus, S. epidermids, S. haemolyticus, K. pneumoniae, A. baumannii, and P. aeruginosa. Additional tests have been performed to assess if the minimum concentration detected through MIC assay may limit the growth of biofilms.

Antibiotic resistance of Helicobacter pylori in Nanjing, China: a cross-section study from 2018 to 2023

Background

The increasing prevalence of antibiotic resistance in cases of Helicobacter pylori (H. pylori) infection has emerged as a significant global issue. This study offers a comprehensive examination of the alterations in drug resistance exhibited by H. pylori in the Nanjing region of China during the preceding five years. Another important objective is to investigate the influence of levofloxacin medication history on genotypic and phenotypic resistance.

Methods

This research screened 4277 individuals diagnosed with H. pylori infection between April 2018 and May 2023. The phenotype and genotypic resistance were evaluated using the Kirby-Bauer disk diffusion and PCR method.

Results

The most recent primary resistance rates for metronidazole, clarithromycin, levofloxacin, amoxicillin, furazolidone, and tetracycline were recorded at 77.23% (2385/3088), 37.24% (1150/3088), 27.72% (856/3088), 0.52% (16/3088), 0.19% (6/3088), and 0.06% (2/3088), respectively. For the recent five years, we observed a notable upsurge in the rate of metronidazole resistance and a slight elevation of clarithromycin and levofloxacin resistance. The documented resistance rates to single-drug, dual-drug, triple-drug, and quadruple-drug regimens were 35.39%, 28.32%, 25.72%, and 0.21%, respectively. The prevalence of multidrug-resistant strains escalated, rising from 37.96% in 2018 to 66.22% in 2023. The rate of phenotypic and genotypic resistance rate (57.10% and 65.57%) observed in strains obtained from patients without a levofloxacin treatment history was significantly lower than the rate in strains obtained from those with a history of levofloxacin treatment (88.73% and 94.74%). The prevailing gyrA mutations were primarily N87K (52.35%, 345/659), accompanied by D91N (13.96%, 92/659), and closely followed by D87G (10.77%, 71/659). For gyrA mutations, the 91-amino acid mutants exhibit a higher likelihood of discrepancies between phenotypic and genotypic resistance than the 87-amino acid mutants.

Conclusion

The extent of antibiotic resistance within H. pylori remains substantial within the Nanjing region. If levofloxacin proves ineffective in eradicating H. pylori during the initial treatment, its use in subsequent treatments is discouraged. The employment of levofloxacin resistance genotype testing can partially substitute conventional antibiotic sensitivity testing. Notably, predicting phenotypic resistance of levofloxacin through PCR requires more attention to the mutation type of gyrA to improve prediction accuracy.

Bacteriology and trends of antimicrobial resistance of Pseudomonas aeruginosa and methicillin-resistant Staphylococcus aureus in otitis media: A retrospective data analysis

OBJECTIVES

Otitis media (OM) has a high prevalence worldwide and the treatment is crucial because hearing loss in children can lead to growth disorders such as language development disorders. The aim of this study is to analyse the changes in bacterial strains and the trends of antibiotic susceptibility in otitis media with effusion (OME), chronic otitis media (COM) and cholesteatomatous otitis media (Chole OM).

DESIGN

This retrospective study involved 2926 patients diagnosed with OME, COM, or Chole OM between January 2000 and December 2020. The clinical data were collected and analysed through chart review from May 2021 to July 2021.

SETTING

Two tertiary medical centres.

PARTICIPANTS

The 2926 OM patients.

MAIN OUTCOMES AND MEASURES

An otorrhea sample was collected on the first day of their hospital visit. Middle ear fluid samples for bacterial culture and antibiotics susceptibility test were collected from patients during middle ear surgery, including ventilation tube insertion. In each type of OM, the distribution of bacterial strains in the 2000s and the 2010s was compared. In addition, changes in the detection rate of methicillin-resistant Staphylococcus aureus (MRSA) and Pseudomonas aeruginosa (PA) and trends in their antibiotic susceptibility over the last 10 years were analysed.

RESULTS

The most frequently detected bacterial strains in OME, COM and Chole OM over the study period were coagulase-negative Staphylococcus (CNS) (29.6%), MRSA (24.1%), and PA (20.1%). Compared to the 2000s, the proportion of non-typable Haemophilus influenzae in OME and MRSA in COM increased in the 2010s (27.4%-31.6% and 1.5%-29.5%, respectively). In total three types of OM, although there was no significant trend of change in detection rates of MRSA, PA, and multidrug resistant-P. aeruginosa (MDR-PA) during the last 10 years, resistance to the Quinolone class of MRSA and PA tended to increase (P < .05).

CONCLUSIONS

The composition of bacterial strains in each types of OM has changed over the past 20 years. Additionally, the antibiotic resistance of MRSA and PA has increased in the last decade. Therefore, when using empirical antibiotics in necessary situations, it is necessary to change to an appropriate antibiotic through a bacterial culture test and antimicrobial susceptibility test.

Antibiogram Profile and Detection of Resistance Genes in Pseudomonas aeruginosa Recovered from Hospital Wastewater Effluent

The nosocomial pathogen Pseudomonas aeruginosa (P. aeruginosa) is characterized by increased prevalence in hospital wastewater and is a public health concern. Untreated wastewater severely challenges human health when discharged into nearby aquatic ecosystems. The antibiogram profiles and resistance genes of P. aeruginosa were evaluated in this study. Wastewater effluents were obtained from a hospital within a six-month sampling period. After the samples were processed and analysed, P. aeruginosa was identified by polymerase chain reaction (PCR) by amplifying OprI and OprL genes. The Kirby-Bauer diffusion technique was employed to check the susceptibility profiles of P. aeruginosa which were further interpreted using CLSI guidelines. A total of 21 resistance genes were investigated among the isolates. The sum of 81 positive P. aeruginosa were isolated in this study. This study's mean count of Pseudomonas aeruginosa ranged from 2.4 × 105 to 6.5 × 105 CFU/mL. A significant proportion of the isolates were susceptible to imipenem (93%), tobramycin (85%), norfloxacin (85%), aztreonam (70%), ciprofloxacin (51%), meropenem (47%), levofloxacin (43%), and gentamicin (40%). Meanwhile, a low susceptibility was recorded for amikacin and ceftazidime. The overall multiple antibiotics resistance index (MARI) ranged from 0.3 to 0.9, with 75% of the multidrug-resistant isolates. The assessment of β-lactam-resistant genes revealed blaOXA-1 (3.7%) and blaSHV (2.4%). The frequency of carbapenem genes was 6.6% for blaIMP, 6.6% for blaKPC, 6.6% for blaoxa-48, 2.2% for blaNDM-1, 2.2% for blaGES, and 2.2% for blaVIM. Of the aminoglycoside genes screened, 8.6% harboured strA, 11.5% harboured aadA, and 1.5% harboured aph(3)-Ia(aphA1). Only one non-β-lactamase gene (qnrA) was detected, with a prevalence of 4.9%. The findings of this study revealed a high prevalence of multidrug-resistant P. aeruginosa and resistance determinants potentially posing environmental health risks.

In silico studies of alkaloids and their derivatives against N-acetyltransferase EIS protein from Mycobacterium tuberculosis

Antibiotic resistance against Mycobacterium tuberculosis (M.tb.) has been a significant cause of death worldwide. The Enhanced intracellular survival (EIS) protein of the bacteria is an acetyltransferase that multiacetylates aminoglycoside antibiotics, preventing them from binding to the bacterial ribosome. To overcome the EIS-mediated antibiotics resistance of M.tb., we compiled 888 alkaloids and derivatives from five different databases and virtually screened them against the EIS receptor. The compound library was filtered down to 87 compounds, which underwent additional analysis and filtration. Moreover, the top 15 most prominent phytocompounds were obtained after the drug-likeness prediction and ADMET screening. Out of 15, nine compounds confirmed the maximum number of hydrogen bond interactions and reliable binding energies during molecular docking. Additionally, the Molecular dynamics (MD) simulation of nine compounds showed the three most stable complexes, further verified by re-docking with mutated protein. The density functional theory (DFT) calculation was performed to identify the HOMO-LUMO energy gaps of the selected three potential compounds. Finally, our selected top lead compounds i.e., Alkaloid AQC2 (PubChem85634496), Nobilisitine A (ChEbi68116), and N-methylcheilanthifoline (ChEbi140673) demonstrated more favourable outcomes when compared with reference compounds (i.e., 39b and 2i) in all parameters used in this study. Therefore, we anticipate that our findings will help to explore and develop natural compound therapy against multi and extensively drug-resistant strains of M.tb.Communicated by Ramaswamy H. Sarma.

Finding Novel AMPs Secreted from the Human Microbiome as Potent Antibacterial and Antibiofilm Agents and Studying Their Synergistic Activity with Ag NCs

Due to the enhanced resistance of bacteria to antibiotics, researchers always try to find effective alternatives to treat drug-resistant bacterial infections. In this context, we have explored antimicrobial peptides (AMPs), which are a broad class of small peptide molecules, and investigated their efficacy as potent antibacterial and antibiofilm agents. AMPs can cause cell death either through disruption of the cell membrane or by inhibiting vital intracellular functions, by binding to RNA, DNA, or intracellular components upon transversion through the cell membrane. We attempted to find potent intracellular cationic AMPs that can demonstrate antibacterial activity through interaction with DNA. As a source of AMPs, we have utilized those that are secreted from the human microbiome with the anticipation that these will be non-toxic in nature. Out of the total 1087 AMPs, 27 were screened on the basis of amino acid length and efficacy to cross the cell membrane barrier. From the list of 27 peptides, 4 candidates were selected through the docking score of these peptides with the DNA binding domain of H2A proteins. Further, the molecular dynamics simulation analysis demonstrated that 2 AMPs, i.e., peptides 7 and 25, are having considerable membrane permeation and DNA binding ability. Further, the in vitro analysis indicated that both peptides 7 and 25 could exhibit potent antibacterial and antibiofilm activities. In order to further enhance the antibiofilm potency, the above AMPs were used as supplements to silver nanoclusters (Ag NCs) to get synergistic activity. The synergistic activity of Ag NCs was found to be significantly increased with both the above AMPs.

Hospital Pharmacists' Viewpoint on Quality Use of Antibiotics and Resistance: A Qualitative Exploration from a Tertiary Care Hospital of Quetta City, Pakistan

Suboptimal antibiotics use and the development of antibiotic resistance is a universal calamity. The theoretical model of therapeutic efficacy correlates quality use of antibiotics with healthcare practitioners' understanding of antibiotic use and resistance. Keeping this phenomenon in mind, we aimed to evaluate hospital pharmacists' understanding of antibiotic use and resistance at a public healthcare institute in Quetta city, Pakistan. This was a qualitative study that employed a semi-structured interview guide for data extraction. The phenomenology-based approach commissioned in-depth, face-to-face interviews with hospital pharmacists stationed at the surgical unit of Sandeman Provincial Hospital, Quetta. The interviews were audio taped followed by transcribed verbatim and were then analyzed for thematic contents by the standard content analysis framework. Although the saturation was reached after the 10th interview, we conducted two additional interviews for definite validation. Content analysis revealed five major themes: (1) Defining antibiotics, quality use of antibiotics and resistance, (2) antibiotic use: awareness and concern, (3) antimicrobial resistance: awareness and concern, (4) responding to antibiotic use and resistance, and (5) barriers to quality use of antibiotics and prevention of antibiotic resistance. The knowledge of quality use of antibiotics and resistance was promising, and the respondents were eager to address the drastic situation. The respondents were aware of the critical situation and provided valuable insights that can offer valued input while promoting the quality use of antibiotics in a developing country. The current study managed to identify an adequate understanding of antibiotic use and resistance among hospital pharmacists. Additionally, prospective concerns and possible predictors of antibiotic resistance were also highlighted. The current findings must be disseminated to the policymakers and prescribers to take prompt restorative actions to address antibiotic use and the development of antibiotic resistance in a developing country like Pakistan.

Understanding Health Worker and Community Antibiotic Prescription-Adherence Practices for Acute Febrile Illness: A Nested Qualitative Study in the Shai-Osudoku District of Ghana and the Development of a Training-and-Communication Intervention

BACKGROUND

The aim was to explore behavioral factors relating to the prescription and communication of prescription-adherence messages for patients with acute febrile illness, from which to develop a training-and-communication (T&C) intervention to be delivered as part of a clinical trial.

METHODS

The study undertook a content analysis of primary, qualitative data collection using in-depth interviews and focus group discussions, informed by the Capability, Opportunity, Motivation (COM-B) theory of behavior, the Theoretical Domains Framework (TDF), and Behavior Change Wheel (BCW) approach, in health facilities (39 health workers) and communities (66 community members) in the Shai-Osudoku District of Ghana.

RESULTS

Health workers perceive that prescribers' and dispensers' communication with patients is influenced by the following factors: patient's educational level, existing disease conditions, health worker's workload, patient's religion, language barrier between health worker and patient, outcome of laboratory results, and medicine availability. Community members' adherence to prescription was influenced by the availability of money and affordability of medicine (outside of provision by the national health insurance scheme), the severity of the condition, work schedule, and forgetfulness.

CONCLUSIONS

Our study contributes to knowledge on nesting qualitative methods in a clinical trial and reveals factors that affect the antibiotic prescription communication process. Tailored messages for patient-specific needs can shape antibiotic prescription adherence behavior and ultimately contribute to decreasing the incidence of antibiotic resistance.

Anti-Biofilm: Machine Learning Assisted Prediction of IC50 Activity of Chemicals Against Biofilms of Microbes Causing Antimicrobial Resistance and Implications in Drug Repurposing

Biofilms are one of the leading causes of antibiotic resistance. It acts as a physical barrier against the human immune system and drugs. The use of anti-biofilm agents helps in tackling the menace of antibiotic resistance. The identification of efficient anti-biofilm chemicals remains a challenge. Therefore, in this study, we developed 'anti-Biofilm', a machine learning technique (MLT) based predictive algorithm for identifying and analyzing the biofilm inhibition of small molecules. The algorithm is developed using experimentally validated anti-biofilm compounds with half maximal inhibitory concentration (IC₅₀) values extracted from aBiofilm resource. Out of the five MLTs, the Support Vector Machine performed best with Pearson's correlation coefficient of 0.75 on the training/testing data set. The robustness of the developed model was further checked using an independent validation dataset. While analyzing the chemical diversity of the anti-biofilm compounds, we observed that they occupy diverse chemical spaces with parent molecules like furanone, urea, phenolic acids, quinolines, and many more. Use of diverse chemicals as input further signifies the robustness of our predictive models. The three best-performing machine learning models were implemented as a user-friendly 'anti-Biofilm' web server (https://bioinfo.imtech.res.in/manojk/antibiofilm/) with different other modules which make 'anti-Biofilm' a comprehensive platform. Therefore, we hope that our initiative will be helpful for the scientific community engaged in identifying effective anti-biofilm agents to target the problem of antimicrobial resistance.

Molecular Characterization of Antibiotic Resistance Determinants in Klebsiella pneumoniae Isolates Recovered from Hospital Effluents in the Eastern Cape Province, South Africa

Klebsiella pneumoniae (K. pneumoniae) is an opportunistic bacteria responsible for many nosocomial and community-acquired infections. The emergence and spread of antibiotic resistances have resulted in widespread epidemics and endemic dissemination of multidrug-resistant pathogens. A total of 145 K. pneumoniae isolates were recovered from hospital wastewater effluents and subjected to antibiogram profiling. Furthermore, the antibiotic resistance determinants were assessed among phenotypic resistant isolates using polymerase chain reaction (PCR). The isolates showed a wide range of antibiotic resistance against 21 selected antibiotics under 11 classes, with the most susceptible shown against imipenem (94.5%) and the most resistant shown against ampicillin (86.2%). The isolates also showed susceptibility to piperacillin/tazobactam (89.0%), ertapenem (87.6%), norfloxacin (86.2%), cefoxitin (86.2%), meropenem (76.6%), doripenem (76.6%), gentamicin (76.6%), chloramphenicol (73.1%), nitrofurantoin (71.7%), ciprofloxacin (79.3%), amikacin (60.7%), and amoxicillin/clavulanic acid (70.4%). Conversely, resistance was also recorded against tetracycline (69%), doxycycline (56.6%), cefuroxime (46.2%), cefotaxime (48.3%), ceftazidime (41.4%). Out of the 32 resistance genes tested, 28 were confirmed, with [tetA (58.8%), tetD (47.89%), tetM (25.2%), tetB (5.9%)], [sul1 (68.4%), sul1I (66.6%)], and [aadA (62.3%), strA (26%), aac(3)-IIa(aacC2)^a (14.4%)] genes having the highest occurrence. Strong significant associations exist among the resistance determinants screened. About 82.7% of the K. pneumoniae isolates were multidrug-resistant (MDR) with a multiple antibiotics resistance index (MARI) range of 0.24 to 1.0. A dual presence of the resistant genes among K. pneumoniae was also observed to occur more frequently than multiple presences. This study reveals a worrisome presence of multidrug-resistant K. pneumoniae isolates and resistance genes in hospital waste effluent, resulting in higher public health risks using untreated surface water for human consumption. As a result, adequate water treatment and monitoring initiatives designed to monitor antimicrobial resistance patterns in the aquatic ecosystem are required.

Antibiotic resistance of Streptococcus pneumoniae in Vietnamese children with severe pneumonia: a cross-sectional study

Background

Streptococcus pneumoniae is the most common bacterium that causes community-acquired pneumonia (CAP) in children. The rate of S. pneumoniae resistance to antibiotics is increasing, particularly in patients with severe CAP. Therefore, the level of antibiotic resistance of S. pneumoniae causing severe CAP in Vietnamese children requires regular monitoring.

Methods

This was a cross-sectional descriptive study. Nasopharyngeal aspiration specimens from children were cultured, isolated, and examined for S. pneumoniae. Bacterial strains were assessed for antimicrobial susceptibility, and the minimum inhibitory concentration (MIC) was determined.

Results

Eighty-nine strains of S. pneumoniae were isolated from 239 children with severe CAP. The majority of isolates were completely non-susceptible to penicillin (1.1% intermediate, 98.9% resistant) and highly resistant to erythromycin (96.6%) and clarithromycin (88.8%); the rate of resistance to ceftriaxone was 16.9%, with the proportion of intermediate resistance at 46.0%; 100% of strains were susceptible to vancomycin and linezolid. For most antibiotics, MIC₅₀ and MIC₉₀ were equal to the resistance threshold according to the Clinical and Laboratory Standards Institute 2021; penicillin had an eight-fold increase in MIC₉₀ (64 mg/L) and ceftriaxone had a 1.5-fold increase in MIC₉₀ (6 mg/L).

Conclusion

Streptococcus pneumoniae isolates described in this study were resistant to many antibiotics. Penicillin should not be the first-line antibiotic of choice, and ceftriaxone at an enhanced dose should be used instead.

Nanotechnology-A Light of Hope for Combating Antibiotic Resistance

Antibiotic usage and resistance are major health concerns. Antibiotic resistance occurs when bacteria evolve to resist the effects of antibiotics, making it impossible to treat infections. The overuse and misuse of antibiotics are the main contributing factors, while environmental stress (such as heavy metals accumulation), unhygienic conditions, illiteracy, and unawareness also contribute to antibiotic resistance. The slow and costly development of new antibiotics has lagged behind the emergence of antibiotic-resistant bacteria, and the overuse of antibiotics leads to negative consequences. The current study used different literature resources to generate an opinion and find a possible solution to antibiotic barriers. Different scientific approaches have been reported to overcome antibiotic resistance. The most useful approach among these is nanotechnology. Nanoparticles can be engineered to disrupt bacterial cell walls or membranes, effectively eliminating resistant strains. Additionally, nanoscale devices enable the real-time monitoring of bacterial populations, allowing for the early detection of resistance emergence. Nanotechnology, along with evolutionary theory offers promising avenues in combating antibiotic resistance. Evolutionary theory helps us understand the mechanisms by which bacteria develop resistance, allowing us to anticipate and counteract their adaptive strategies. By studying the selective pressures that drive resistance, we can therefore design more effective interventions or traps. The synergy between the evolutionary theory and nanotechnology presents a powerful approach to combat antibiotic resistance, offering new avenues for the development of effective treatments and the preservation of our antibiotic arsenal.

An Evaluation of the Impact of Increasing the Awareness of the WHO Access, Watch, and Reserve (AWaRe) Antibiotics Classification on Knowledge, Attitudes, and Hospital Antibiotic Prescribing Practices

The study aims to determine the effect of enhancing knowledge and awareness of the WHO Access, Watch, and Reserve (AWaRe) antibiotics classification on hospital clinical staff's knowledge, attitudes and antibiotic prescribing practices. A pre-post-intervention study design was employed. The intervention was an educational activity that involved teaching physicians and pharmacists about the AWaRe classification and the risk of antibiotic resistance. A questionnaire was administered to clinical staff pre-and post-intervention. In the pre-interventional stage, 78.5% of participants stated they had not heard about the AWaRe classification of antibiotics. After receiving the intervention: the knowledge regarding the meaning and purpose of AWaRe classification of antibiotics increased from 39.1% to 75.4%; the percentage of participants who agreed with following the AWaRe classification of antibiotics in their practice increased from 21.7% to 58.5%; and the percentage of participants who agreed that AWaRe classification of antibiotics can suggest safe choices of antibiotics increased from 56.5% to 90.8%. Hospital antibiotic use of the Access group increased by 6.6% from pre- to post-intervention. The use of the Watch group and Reserve group decreased post-intervention by 1.7%, and 43.1%, respectively. This study showed important gaps in knowledge and attitudes towards AWaRe, highlighting the need for increasing the awareness of the AWaRe tool amongst healthcare practitioners to ensure rational use of antibiotics.

Whole-genome sequencing of multidrug resistance Salmonella Typhi clinical strains isolated from Balochistan, Pakistan

Introduction

Salmonella enterica serovar Typhi (S. Typhi) is a major cause of morbidity and mortality in developing countries, contributing significantly to the global disease burden.

Methods

In this study, S. Typhi strains were isolated from 100 patients exhibiting symptoms of typhoid fever at a tertiary care hospital in Pakistan. Antimicrobial testing of all isolates was performed to determine the sensitivity and resistance pattern. Three MDR strains, namely QS194, QS430, and QS468, were subjected to whole genome sequencing for genomic characterization.

Results and Discussion

MLST analysis showed that QS194, belonged to ST19, which is commonly associated with Salmonella enterica serovar typhimurium. In contrast, QS430 and QS468, belonged to ST1, a sequence type frequently associated with S. Typhi. PlasmidFinder identified the presence of IncFIB(S) and IncFII(S) plasmids in QS194, while IncQ1 was found in QS468. No plasmid was detected in QS430. CARD-based analysis showed that the strains were largely resistant to a variety of antibiotics and disinfecting agents/antiseptics, including fluoroquinolones, cephalosporins, monobactams, cephamycins, penams, phenicols, tetracyclines, rifamycins, aminoglycosides, etc. The S. Typhi strains possessed various virulence factors, such as Vi antigen, Agf/Csg, Bcf, Fim, Pef, etc. The sequencing data indicated that the strains had antibiotic resistance determinants and shared common virulence factors. Pangenome analysis of the selected S. Typhi strains identified 13,237 genes, with 3,611 being core genes, 2,093 shell genes, and 7,533 cloud genes. Genome-based typing and horizontal gene transfer analysis revealed that the strains had different evolutionary origins and may have adapted to distinct environments or host organisms. These findings provide important insights into the genetic characteristics of S. Typhi strains and their potential association with various ecological niches and host organisms.

Screening of Antibiotic and Virulence Genes from Whole Genome Sequenced Cronobacter sakazakii Isolated from Food and Milk-Producing Environments

The objective of this study was to use whole-genome sequencing (WGS) to screen for genes encoding for antibiotic resistance, fitness and virulence in Cronobacter sakazakii strains that had been isolated from food and powdered-milk-producing environments. Virulence (VGs) and antibiotic-resistance genes (ARGs) were detected with the Comprehensive Antibiotic Resistance Database (CARD) platform, ResFinder and PlasmidFinder tools. Susceptibility testing was performed using disk diffusion. Fifteen presumptive strains of Cronobacter spp. were identified by MALDI-TOF MS and ribosomal-MLST. Nine C. sakazakii strains were found in the meningitic pathovar ST4: two were ST83 and one was ST1. The C. sakazakii ST4 strains were further distinguished using core genome MLST based on 3678 loci. Almost all (93%) strains were resistant to cephalotin and 33% were resistant to ampicillin. In addition, 20 ARGs, mainly involved in regulatory and efflux antibiotics, were detected. Ninety-nine VGs were detected that encoded for OmpA, siderophores and genes involved in metabolism and stress. The IncFIB (pCTU3) plasmid was detected, and the prevalent mobile genetic elements (MGEs) were ISEsa1, ISEc52 and ISEhe3. The C. sakazakii isolates analyzed in this study harbored ARGs and VGs, which could have contributed to their persistence in powdered-milk-producing environments, and increase the risk of infection in susceptible population groups.

Revealing the Second and the Third Causes of AgNPs Property to Restore the Bacterial Susceptibility to Antibiotics

The increase in bacterial resistance to antibiotics is a global problem for public health. In our previous works, it was shown that the application of AgNPs in cow mastitis treatment increased S. aureus and S. dysgalactiae susceptibility to 31 antibiotics due to a decrease in the bacterial efflux effect. The aim of the present work was to shed light on whether the change in adhesive and anti-lysozyme activities caused by AgNPs also contribute to the restoration of bacterial susceptibility to antibiotics. In vivo sampling was performed before and after cow mastitis treatments with antibiotics or AgNPs. The isolates were identified, and the adhesive and anti-lysozyme activities were assessed. These data were compared with the results obtained for in vitro pre-treatment of reference bacteria with AgNPs or antibiotics. The present study revealed that bacterial treatments in vitro and in vivo with AgNPs: (1) decrease the bacterial ability to adhere to cells to start an infection and (2) decrease bacterial anti-lysozyme activity, thereby enhancing the activity of lysozyme, a natural "antibiotic" present in living organisms. The obtained data contribute to the perspective of the future application of AgNPs for recovering the activity of antibiotics rapidly disappearing from the market.

Human Salmonellosis: A Continuous Global Threat in the Farm-to-Fork Food Safety Continuum

Salmonella is one of the most common zoonotic foodborne pathogens and a worldwide public health threat. Salmonella enterica is the most pathogenic among Salmonella species, comprising over 2500 serovars. It causes typhoid fever and gastroenteritis, and the serovars responsible for the later disease are known as non-typhoidal Salmonella (NTS). Salmonella transmission to humans happens along the farm-to-fork continuum via contaminated animal- and plant-derived foods, including poultry, eggs, fish, pork, beef, vegetables, fruits, nuts, and flour. Several virulence factors have been recognized to play a vital role in attaching, invading, and evading the host defense system. These factors include capsule, adhesion proteins, flagella, plasmids, and type III secretion systems that are encoded on the Salmonella pathogenicity islands. The increased global prevalence of NTS serovars in recent years indicates that the control approaches centered on alleviating the food animals' contamination along the food chain have been unsuccessful. Moreover, the emergence of antibiotic-resistant Salmonella variants suggests a potential food safety crisis. This review summarizes the current state of the knowledge on the nomenclature, microbiological features, virulence factors, and the mechanism of antimicrobial resistance of Salmonella. Furthermore, it provides insights into the pathogenesis and epidemiology of Salmonella infections. The recent outbreaks of salmonellosis reported in different clinical settings and geographical regions, including Africa, the Middle East and North Africa, Latin America, Europe, and the USA in the farm-to-fork continuum, are also highlighted.

Colistin resistance mechanisms in Gram-negative bacteria: a Focus on Escherichia coli

Multidrug-resistant (MDR) Escherichia coli strains have rapidly increased worldwide, and effective antibiotic therapeutic options are becoming more restricted. As a polymyxin antibiotic, colistin has a long history of usage, and it is used as a final line of treatment for severe infections by Gram-negative bacteria (GNB) with high-level resistance. However, its application has been challenged by the emergence of E. coli colistin resistance. Hence, determining the mechanism that confers colistin resistance is crucial for monitoring and controlling the dissemination of colistin-resistant E. coli strains. This comprehensive review summarizes colistin resistance mechanisms in E. coli strains and concentrates on the history, mode of action, and therapeutic implications of colistin. We have mainly focused on the fundamental mechanisms of colistin resistance that are mediated by chromosomal or plasmid elements and discussed major mutations in the two-component systems (TCSs) genes and plasmids that transmit the mobilized colistin resistance resistant genes in E. coli strains.

Rapid determination of Proteus mirabilis susceptibility to antibiotics using infrared spectroscopy in tandem with random forest

Bacterial infections cause serious illnesses that are treated with antibiotics. Currently used methods for detecting bacterial antibiotic susceptibility consume 48-72 h, leading to overuse of antibiotics. Thus, many bacterial species have acquired resistance to a broad range of available antibiotics. There is an urgent need to develop efficient methods for rapid determination of bacterial susceptibility to antibiotics. The combination of machine learning and Fourier-transform infrared (FTIR) spectroscopy has generated a promising diagnostic approach in medicine and biology. Our main goal is to examine the potential of FTIR spectroscopy to determine the susceptibility of urinary tract infection-Proteus mirabilis to a specific range of antibiotics, within about 20 min after 24 h culture and identification. We measured the infrared spectra of 489 different P. mirabilis isolates and used random forest to analyze this spectral database. A classification success rate of ~84% was achieved in differentiating between the resistant and sensitive isolates based on their susceptibility to ceftazidime, ceftriaxone, cefuroxime, cefuroxime axetil, cephalexin, ciprofloxacin, gentamicin, and sulfamethoxazole antibiotics in a time span of 24 h instead of 48 h.

Antibacterial and anti-biofilm activities of Disaspidin BB against Staphylococcus epidermidis

Introduction

Staphylococcus epidermidis infections are an important concern in worldwide, especially when associated with biofilms, and resistance of this agent to many drugs makes the situation even worse. We investigated the inhibitory effect of Disaspidin BB obtained from plant extracts and purifications on clinical S. epidermidis strains and their biofilms, and preliminarily investigated its mechanism of of its anti-biofilm activity.

Methods and Results

The broth dilution method was used to determine the minimum inhibitory concentrations (MIC) of Disaspidin BB on 11 clinical S. epidermidis strains (MIC value of 0.63 ~ 2.5 μg/ml). SEP-05 was found to be erythromycin-resistant (MIC value>8 μg/ml) and Disaspidin BB sensitive with an MIC value of 0.63 μg/ml. The time-kill curve assay indicated that the antibacterial activity of Disaspidin BB against SEP-05 with concentration dependence. The metabolic activity and total biomass of the drug-treated SEP-05 biofilm in each stage were significantly inhibited by the crystalline violet and XTT assay, and the scavenging effect of Disaspidin BB on SEP-05 biofilm was also confirmed by SEM observation. The results of real-time quantitative PCR showed that subinhibitory concentrations Disaspidin BB can inhibit biofilm formation by affecting the expression level of key genes (aap, atlE, icaA, luxS, recA) in SEP-05 biofilm formation. In addition, the content of polysaccharides, proteins and extracellular DNA in biofilm matrix after the intervention of Disaspidin BB was significantly reduced, and it was tentatively determined that the ability of SEP-05 biofilm formation and its stability were thus disturbed.

Discussion

The results show that Disaspidin BB has promising antibacterial effect on erythromycin-resistant S. epidermidis and significant scavenging effect on its biofilm, which provides a theoretical basis for the further development of BB as a new drug for the treatment of skin infections caused by S. epidermidis.

Research of Antibiotic Residues and Bacterial Strain's Antibiotic Resistance Profile in the Liquid Effluents Evacuated in Nature by Two CHUs and a Mixed WWTP of Ouagadougou (Burkina Faso)

Background

In Burkina Faso, suspicions have been raised that hospital liquid effluents are a source of microbiological contaminants in surface waters of urban and peri-urban areas. This study aimed to determine the antibiotic residues and the antibiotic resistance phenotype of potential pathogenic bacteria in the hospital liquid effluents discharged into nature by the CHUs Bogodogo, Yalgado Ouédraogo and the WWTS of Kossodo.

Methods

Fifteen samples of liquid effluents discharged into nature were collected. Antibiotic residues were identified by HPLC. A wavelength of 254 nm for the UV detector was set. Antibiotic testing was realized according to CASFM 2019 recommendations.

Results

Three molecules including Amoxicillin, Chloramphenicol and Ceftriaxone were detected in 13 samples. The strains characterized were 06 E. coli, 09 Pseudomonas spp, 05 Staphylococcus aureus and 04 Salmonella spp. Thus, none of the strains was resistant to Imipenem, but they were resistant to Amoxiclav with rates of 83.33% (E. coli), 88.88% (Pseudomonas spp) and 100% (Staphylococcus aureus and Salmonella spp).

Conclusion

Ouagadougou hospital liquid effluents discharged into nature are contaminated with antibiotic residues and potential pathogenic bacteria.

Designing Functionally Substituted Pyridine-Carbohydrazides for Potent Antibacterial and Devouring Antifungal Effect on Multidrug Resistant (MDR) Strains

The emergence of multidrug-resistant (MDR) pathogens and the gradual depletion of available antibiotics have exacerbated the need for novel antimicrobial agents with minimal toxicity. Herein, we report functionally substituted pyridine carbohydrazide with remarkable antimicrobial effect on multi-drug resistant strains. In the series, compound 6 had potent activity against four MDR strains of Candida spp., with minimum inhibitory concentration (MIC) values being in the range of 16-24 µg/mL and percentage inhibition up to 92.57%, which was exceptional when compared to broad-spectrum antifungal drug fluconazole (MIC = 20 µg/mL, 81.88% inhibition). Substitution of the octyl chain in 6 with a shorter butyl chain resulted in a significant anti-bacterial effect of 4 against Pseudomonas aeruginosa (ATCC 27853), the MIC value being 2-fold superior to the standard combination of ampicillin/cloxacillin. Time-kill kinetics assays were used to discern the efficacy and pharmacodynamics of the potent compounds. Further, hemolysis tests confirmed that both compounds had better safety profiles than the standard drugs. Besides, molecular docking simulations were used to further explore their mode of interaction with target proteins. Overall results suggest that these compounds have the potential to become promising antimicrobial drugs against MDR strains.

Effective Therapeutic Options for Melioidosis: Antibiotics versus Phage Therapy

Melioidosis, also known as Whitmore's disease, is a potentially fatal infection caused by the Gram-negative bacteria Burkholderia pseudomallei with a mortality rate of 10-50%. The condition is a "glanders-like" illness prevalent in Southeast Asian and Northern Australian regions and can affect humans, animals, and sometimes plants. Melioidosis received the epithet "the great mimicker" owing to its vast spectrum of non-specific clinical manifestations, such as localised abscesses, septicaemia, pneumonia, septic arthritis, osteomyelitis, and encephalomyelitis, which often lead to misdiagnosis and ineffective treatment. To date, antibiotics remain the backbone of melioidosis treatment, which includes intravenous therapy with ceftazidime or meropenem, followed by oral therapy with TMP-SMX or amoxicillin/clavulanic acid and supported by adjunctive treatment. However, bacteria have developed resistance to a series of antibiotics, including clinically significant ones, during treatment. Therefore, phage therapy has gained unprecedented interest and has been proposed as an alternative treatment. Although no effective phage therapy has been published, the findings of experimental phage therapies suggest that the concept could be feasible. This article reviews the benefits and limitations of antibiotics and phage therapy in terms of established regimens, bacterial resistance, host specificity, and biofilm degradation.

Heavy Metal (Arsenic) Induced Antibiotic Resistance among Extended-Spectrum β-Lactamase (ESBL) Producing Bacteria of Nosocomial Origin

Antimicrobial resistance (AMR) is a leading cause of treatment failure for many infectious diseases worldwide. Improper overdosing and the misuse of antibiotics contributes significantly to the emergence of drug-resistant bacteria. The co-contamination of heavy metals and antibiotic compounds existing in the environment might also be involved in the spread of AMR. The current study was designed to test the efficacy of heavy metals (arsenic) induced AMR patterns in clinically isolated extended-spectrum β-lactamase (ESBL) producing bacteria. A total of 300 clinically isolated ESBL-producing bacteria were collected from a tertiary care hospital in Lahore, Pakistan, with the demographic characteristics of patients. After the collection of bacterial isolates, these were reinoculated on agar media for reidentification purposes. Direct antimicrobial sensitivity testing (AST) for bacterial isolates by disk diffusion methods was used to determine the AST patterns with and without heavy metal. The heavy metal was concentrated in dilutions of 1.25 g/mL. The collected bacterial isolates were isolated from wounds (n = 63, 21%), urine (n = 112, 37.3%), blood (n = 43, 14.3%), pus (n = 49, 16.3%), and aspirate (n = 33, 11%) samples. From the total 300 bacterial isolates, n = 172 were Escherichia coli (57.3%), 57 were Klebsiella spp. (19%), 32 were Pseudomonas aeruginosa (10.6%), 21 were Proteus mirabilis (7%) and 18 were Enterobacter spp. (6%). Most of the antibiotic drugs were found resistant to tested bacteria. Colistin and Polymyxin-B showed the highest sensitivity against all tested bacteria, but when tested with heavy metals, these antibiotics were also found to be significantly resistant. We found that heavy metals induced the resistance capability in bacterial isolates, which leads to higher AMR patterns as compared to without heavy metal tested isolates. The results of the current study explored the heavy metal as an inducer of AMR and may contribute to the formation and spread of AMR in settings that are contaminated with heavy metals.

Molecular Characteristics and Antibiotic Resistance of Staphylococcus aureus Isolated from Patient and Food Samples in Shijiazhuang, China

Staphylococcus aureus (S. aureus) is a common opportunistic and zoonotic pathogen in the world and could easily cause human infections and food contaminations. This study investigated the sequence typing and resistance profiles of S. aureus isolates from patient and food samples in Shijiazhuang, China. A total of 101 S. aureus isolates were distributed into six clonal complexes (CCs) and 16 singletons. A total of 86 patient isolates were distributed into six clonal CCs and 12 singletons, including a new ST. CC59, CC5, CC22, and CC398 were the predominant CCs of patient isolates. A total of 15 foodborne S. aureus isolates were distributed into 3 CCs and 4 STs, and CC1 was the most prevalent CC. Moreover, 101 S. aureus isolates had high resistance to penicillin and low resistance to chloramphenicol and rifampicin. A total of 39 strains of methicillin-resistant Staphylococcus aureus (MRSA) were detected in this study, including thirty-eight strains of patient isolates (44.2%, 38/86) and one strain of food isolates (6.7%, 1/15). MRSA-ST5, MRSA-ST59, and MRSA-ST239 were the predominant MRSA isolates in hospitals. The present study explained the relationship between S. aureus isolated from patient and food samples and indicated the risks of S. aureus in infectious diseases.

Applying the Kirkpatrick model to evaluate dental students' experience of learning about antibiotics use and resistance

INTRODUCTION

"Antibiotic resistance" is of main concern in global health and that it could hinder the achievement of sustainable development goals. One of the reported contributing factors is the irrational prescribing behaviour of healthcare professionals including dentists. Efforts to design and evaluate effective educational programmes for undergraduate dental students about appropriate prescribing behaviour during their early educational years could mitigate the risk of antibiotic resistance.

MATERIALS AND METHODS

A total of 322 students participated in the study. Their knowledge of antibiotics and antibiotic resistance was assessed. Students received a specially designed, interactive educational programme. The success of the programme was assessed after the educational sessions and 2 years later using Kirkpatrick's four-level evaluation model.

RESULTS

This study is the first study to use Kirkpatrick model to evaluate an educational programme for dental students. The results of the first level of evaluation showed an overall satisfaction score of 82.1%. The second level revealed an increase in the percentage of correct answers after the educational sessions from 68.3% to 80%, and significant agreement with responsible antibiotics usage (p-value = .020, Effect size = 0.121). The third level showed that the percentage of correct answers 2 years later was 87.5%. The fourth level confirmed the success of the programme as 88.9% of participants reported using the knowledge gained from the programme when prescribing antibiotics.

CONCLUSIONS

Our study emphasises the success of the used educational programme and highlights the need for educational interventions in the under graduate dental curriculum.

Public Knowledge, Attitudes, and Practices Towards Antibiotic Use and Antimicrobial Resistance in the Western Region of Saudi Arabia

Introduction Antimicrobial resistance (AMR) is one of the major concerns for global health. Inappropriate use of antibiotics is speeding up the process of AMR. The aim of this study was to assess the knowledge, attitude, and practices (KAP) of the population of the western region of Saudi Arabia towards antibiotic use and AMR. Methods A cross-sectional study was conducted using an online questionnaire via social media platforms. It consisted of four parts: first, the participant's sociodemographic characteristics. Second, an assessment of the knowledge of antibiotic use and AMR. The third and fourth parts are to evaluate the attitude and practices towards antibiotic use and AMR. Results From a total of 501 participants, 379 (75.6%) were females, and 354 (70.7%) of the participants had a college degree. Regarding the overall knowledge of antibiotics and AMR, 277 (55.29%) of the respondents had poor knowledge. In addition, 443 (88.42%) of the participants also reported having an inadequate attitude. Moreover, inadequate practices related to the use of antibiotics were also reported among 305 (60.89%) of the participants. Factors associated with the level of knowledge are gender, age, educational level, and occupational status. Regarding occupation, being in a medical job was associated with a better knowledge of antibiotics and AMR than other occupations. Conclusion Our study revealed poor overall knowledge, attitudes, and practices toward antibiotics and AMR among participants. Conducting educational health campaigns for the public that aim to promote awareness and enhance good practices, emphasizing the role of health care providers in health education for the public, and enforcing strict regulations to control the non-prescription dispensing of antibiotics will help to combat this issue. However, future research on this topic is required.

Antibiotics' Sustainability: Another Issue in the Fight against Antimicrobial Resistance

The spread of antimicrobial resistance (AMR) is still a major threat to global health that is likely to worsen also as a consequence of the COVID-19 pandemic. For this reason, there is an urgent need to develop new compounds and novel alternative treatments. Furthermore, the new lines of action must consider the issue of antibiotics' sustainability. Within this persrective, we have highlighted the main points on which actions in this perspective are possible.

The neonatal intestinal resistome and factors that influence it - a systematic review

BACKGROUND

The intestinal microbiome provides a reservoir for antibiotic resistance genes (ARGs). The neonatal microbiome is more susceptible to disturbance from external factors than the established microbiome.

OBJECTIVES

In this review, we systematically summarise studies which investigated the intestinal resistome in neonates.

DATA SOURCES

MEDLINE and Embase databases were searched.

STUDY ELIGIBILITY CRITERIA

We included original studies which investigated ARGs in stool or rectal swabs in neonates using molecular diagnostics.

METHODS OF DATA SYNTHESIS

Two authors independently extracted data. Data was summarised in tables.

RESULTS

Our search identified 2,701 studies, of which 23 (22 cohorts) were included. The studies show that the neonatal intestine harbours a high abundance and variety of ARGs, even in the absence of direct antibiotic exposure. The most-commonly found ARGs confer resistance to aminoglycosides, beta-lactams, macrolides, tetracyclines or multi-drug resistance. There is evidence that ARGs can be transferred from mothers to neonates. Interestingly, however, compared to mothers, neonates are reported to have a higher abundance of ARGs. One likely reason for this is the bacterial phylogenetic composition with a high abundance of Gammaproteobacteria in neonatal stool. Factors that have been associated with a higher abundance of ARGs are intrapartum and neonatal antibiotic use. Breastfeeding and neonatal probiotic use have been associated with a lower abundance of ARGs. Antibiotics during pregnancy, delivery mode or sex are reported to have little effect. However, this might be because studies were underpowered and because it is difficult to account for effect modifiers.

DISCUSSION

The neonatal intestine seems to have a lower colonisation resistance, which could make it easier for antibiotic-resistant populations to establish themselves. Future studies will help in the development of evidence-based interventions to modulate the abundance of ARGs in neonates, for example, by the use of pre- and probiotics and bacteriophages.

Bacteriophage and Bacterial Susceptibility, Resistance, and Tolerance to Antibiotics

Bacteriophages, viruses that infect and replicate within bacteria, impact bacterial responses to antibiotics in complex ways. Recent studies using lytic bacteriophages to treat bacterial infections (phage therapy) demonstrate that phages can promote susceptibility to chemical antibiotics and that phage/antibiotic synergy is possible. However, both lytic and lysogenic bacteriophages can contribute to antimicrobial resistance. In particular, some phages mediate the horizontal transfer of antibiotic resistance genes between bacteria via transduction and other mechanisms. In addition, chronic infection filamentous phages can promote antimicrobial tolerance, the ability of bacteria to persist in the face of antibiotics. In particular, filamentous phages serve as structural elements in bacterial biofilms and prevent the penetration of antibiotics. Over time, these contributions to antibiotic tolerance favor the selection of resistance clones. Here, we review recent insights into bacteriophage contributions to antibiotic susceptibility, resistance, and tolerance. We discuss the mechanisms involved in these effects and address their impact on bacterial fitness.

Human Serum Alters the Metabolism and Antibiotic Susceptibility of Staphylococcus aureus

Staphylococcus aureus is a common source of hospital-acquired bacterial infections, where the emergence of antibiotic resistance is a serious human health concern. Most investigations into S. aureus virulence and antibiotic resistance have relied on in vitro cultivation conditions and optimized media formulations. However, S. aureus can survive and adapt to a hostile host environment or antibiotic treatments by rapidly adjusting its metabolic activity. To assess this metabolic response, S. aureus strains susceptible and nonsusceptible to daptomycin were cultivated in medium supplemented with 55% serum to more closely approximate in vivo conditions. Growth analyses, MIC testing, and NMR-based metabolomics determined that serum decreased daptomycin susceptibility and altered metabolism in S. aureus. Both S. aureus strains exhibited altered amino acid biosynthesis and catabolism, enhanced fermentation, and a modified salt tolerance response. The observation that growth conditions defined an adaptive metabolic response to antibiotics by S. aureus may be a critical consideration for designing an effective drug discovery study.

Inhibitors of Bacterial Extracellular Vesicles

Both Gram-positive and Gram-negative bacteria can secrete extracellular vesicles (EVs), which contain numerous active substances. EVs mediate bacterial interactions with their hosts or other microbes. Bacterial EVs play a double-edged role in infections through various mechanisms, including the delivery of virulence factors, modulating immune responses, mediating antibiotic resistance, and inhibiting competitive microbes. The spread of antibiotic resistance continues to represent a difficult clinical challenge. Therefore, the investigation of novel therapeutics is a valuable research endeavor for targeting antibiotic-resistant bacterial infections. As a pathogenic substance of bacteria, bacterial EVs have gained increased attention. Thus, EV inhibitors are expected to function as novel antimicrobial agents. The inhibition of EV production, EV activity, and EV-stimulated inflammation are considered potential pathways. This review primarily introduces compounds that effectively inhibit bacterial EVs and evaluates the prospects of their application.

Enteral broad-spectrum antibiotics antagonize the effect of fecal microbiota transplantation in preterm pigs

Preterm infants are at risk of multiple morbidities including necrotizing enterocolitis (NEC). Suspected NEC patients receive intravenous antibiotics (AB) to prevent sepsis, although enteral AB is arguably more effective at reducing NEC but is rarely used due to the risk of AB resistance. Fecal microbiota transplantation (FMT) has shown protective effects against NEC in animal experiments, but the interaction between AB and FMT has not been investigated in neonates. We hypothesized that administration of enteral AB followed by rectal FMT would effectively prevent NEC with negligible changes in AB resistance and systemic immunity. Using preterm piglets, we examined host and gut microbiota responses to AB, FMT, or a sequential combination thereof, with emphasis on NEC development. In a saline-controlled experiment, preterm piglets (n = 67) received oro-gastric neomycin (50 mg/kg/d) and amoxicillin-clavulanate (50/12.5 mg/kg/d) (hereafter AB) for four days after cesarean delivery, and were subsequently given rectal FMT from healthy suckling piglet donors. Whereas AB protected the stomach and small intestine, and FMT primarily protected the colon, the sequential combination treatment surprisingly provided no NEC protection. Furthermore, minor changes in the gut microbiota composition were observed in response to either treatment, although AB treatment decreased species diversity and increased AB resistance among coliform bacteria and Enterococci, which were both partly reversed by FMT. Besides, enteral AB treatment suppressed cellular and functional systemic immune development, which was not prevented by subsequent FMT. We discovered an antagonistic relationship between enteral AB and FMT in terms of NEC development. The outcome may depend on choice of AB compounds, FMT composition, doses, treatment duration, and administration routes, but these results challenge the applicability of enteral AB and FMT in preterm infants.

High frequency of antimicrobial resistance and virulence gene in Shigella species isolated from pediatric patients in an Iranian Referral Hospital

BACKGROUND

Shigella is a main cause of gastroenteritis and it is responsible for 5 to 10 % of diarrhea through the world. The aims of this study were to assess the antibiotic susceptibility pattern and the presence of 3 common virulence genes (sigA, virF, invE) of Shigella strains isolated from patients with gastroenteritis in Children's Medical Center Hospital, Tehran, Iran.

METHODS

Over a period of 15 months, all Shigella species collected from the patients with gastroenteritis were entered to the study. Susceptibility testing of all isolates towards different antibiotics was performed using the disk diffusion method and the prevalence of virulence genes was detected by polymerase chain reaction (PCR) technology.

RESULTS

Among a total of 183 Shigella strains, 128 Shigella sonnei (70%) and 55 S. flexneri (30%) were isolated. The resistance rate to the antibiotics in S. sonnei strains was higher than S. flexneri. The most sensitive antibiotics for S. flexneri strains were gentamicin (98%), amikacin (85%) and ciprofloxacin (82%), while high resistance rate to trimethoprim-sulfamethoxazole (96%), ampicillin (96%), nalidixic acid (64%) and cefotaxime (60%) was observed. The frequency of invE, virF and sigA gene in S. flexneri strains was 89 %, 93 % and 56 %, respectively; whereas they found in 93 %, 96 %, and 100 % of S. sonnei strains, respectively. SigA gene was identified significantly higher in the S. sonnei strains (100%). There was no significant difference between the presence of virF and invE genes among Shigella strains.

CONCLUSION

The high presence of sigA gene in S. sonnei strains plays an important role in its pathogenesis, and the high frequency of invE and virF genes showed that this classical pathway regulating the expression of Shigella virulence factor genes could play a key role in the pathogenesis of this bacterium.

Escherichia coli resistance patterns, empiric and targeted antibiotic prescriptions in children: a single center experience

BACKGROUND AND AIM

Antibiotic resistance represents one of the major public health issues, due to the potential future ineffectiveness of available antibiotics. However, epidemiological studies on E. coli antibiotic resistance patterns in the pediatric population are limited.

METHODS

We conducted a retrospective analysis on children younger than 18 years of age admitted to the Department of Pediatrics from April 2016 to April 2018 with E. coli isolation on biological materials.

RESULTS

205 subjects were included in the study (mean age 1.6 years). We found an overall low rate of resistance of E. coli isolates to Amoxicil-lin/Clavulanate (20%), Cephalosporins (6.3%) and Aminoglycosides (6.3%), while no isolates were resistant to Carbapenems. Presence of invasive devices and intensive care admissions were as-sociated with resistance to Cephalosporines (P < 0.001; OR 9.21, 95% CI 2.7 - 31.39) and Amino-glycosides (P < 0.004; OR 5.42, 95% CI 1.71 - 17.15), while no factors associated with resistance to the other antibiotics were found.

CONCLUSIONS

Aminoglycosides and Cephalosporins were frequently used as empiric therapy, whereas targeted therapies aimed at sparing these classes of antibiotics once antibiograms were available have not always been established. These data may inform local antimicrobial stewardship and guide the development of programs aiming at a better use of antibiotics.

Pharmacodynamics of Linezolid Plus Fosfomycin Against Vancomycin-Resistant Enterococcus faecium in a Hollow Fiber Infection Model

The optimal therapy for severe infections caused by vancomycin-resistant Enterococcus faecium (VREfm) remains unclear, but the combination of linezolid and fosfomycin may be a good choice. The 24-h static-concentration time-kill study (SCTK) was used to preliminarily explore the pharmacodynamics of linezolid combined with fosfomycin against three clinical isolates. Subsequently, a hollow-fibre infection model (HFIM) was used for the first time to further investigate the pharmacodynamic activity of the co-administration regimen against selected isolates over 72 h. To further quantify the relationship between fosfomycin resistance and bacterial virulence in VREfm, the Galleria mellonella infection model and virulence genes expression experiments were also performed. The results of SCTK showed that the combination of linezolid and fosfomycin had additive effect on all strains. In the HFIM, the dosage regimen of linezolid (12 mg/L, steady-state concentration) combined with fosfomycin (8 g administered intravenously every 8 h as a 1 h infusion) not only produced a sustained bactericidal effect of 3∼4 log₁₀ CFU/mL over 72 h, but also completely eradicated the resistant subpopulations. The expression of virulence genes was down-regulated to at least 0.222-fold in fosfomycin-resistant strains compared with baseline isolate, while survival rates of G. mellonella was increased (G. mellonella survival ≥45% at 72 h). For severe infections caused by VREfm, neither linezolid nor fosfomycin monotherapy regimens inhibited amplification of the resistant subpopulations, and the development of fosfomycin resistance was at the expense of the virulence of VREfm. The combination of linezolid with fosfomycin produced a sustained bactericidal effect and completely eradicated the resistant subpopulations. Linezolid plus Fosfomycin is a promising combination for therapy of severe infections caused by VREfm.

Prevalence and Resistance Patterns of Pediatric Urinary Tract Infections in Bahrain

Background

Urinary tract infections (UTI) are a commonly encountered infection in the pediatric age group. Knowledge of the causative pathogens and their antimicrobial resistance patterns in specific geographical locations is important to provide optimum care. The aim of this study is to describe the prevalence and the antimicrobial resistance patterns of the pathogens causing UTI in the pediatric age group in one tertiary inpatient Pediatric unit in Bahrain.

Methods

This is a retrospective cross-sectional study, conducted at King Hamad University Hospital (KHUH), Bahrain. The inclusion criteria consisted of patients ≤ 14 years of age admitted to the Pediatrics department at KHUH with bacteriologically proven UTI between the months of January 2018 and May 2021. Patients who were identified to have chronic urinary tract conditions or neurodevelopmental problems involving the urinary tract were excluded from the study. Electronic medical records were used to collect data regarding the isolated pathogens and sensitivity testing results.

Results

A total of 242 cases with positive culture were included. The most common bacteria causing UTI in this sample were successively Escherichia coli (68.60%), Klebsiella pneumoniae (10.30%), Proteus mirabilis (4.69%) and Pseudomonas aeruginosa (3.31%) (p<0.01). E. coli was most resistant to cefazolin (94%), followed by ampicillin (62.68%), whilst it was most sensitive to nitrofurantoin (98.96%) followed by amikacin (98.43%) (p<0.01). K. pneumoniae showed the highest rate of resistance to ampicillin (95.24%) followed by cefazolin (83.33%), meanwhile having the highest sensitivity rate to amikacin (95.24%), followed by ciprofloxacin (90.48%). P. mirabilis had the highest resistance to cefazolin (100%) followed by nitrofurantoin (87.50%), while having the highest sensitivity to piperacillin/tazobactam (100%).

Conclusion

E. coli is the most common cause of UTI in the pediatric population and it was found to be most sensitive to nitrofurantoin and amikacin whilst being relatively resistant to cefazolin and ampicillin. Similarities between our study and previous studies around the world were found when comparing the antibiotics resistance patterns. Nevertheless, it is our recommendation that empirical antibiotic selection should be tailored to the local data collected from the region.

Exploring Undergraduate Pharmacy Students Perspectives Towards Antibiotics Use, Antibiotic Resistance, and Antibiotic Stewardship Programs Along With the Pharmacy Teachers' Perspectives: A Mixed-Methods Study From Pakistan

Background: Antibiotic resistance (ABR) is one of the major issues around the globe. Timely education and awareness of pharmacy students regarding the appropriate use of antibiotics, ABR, and antimicrobial stewardships are required.

Methods: The present study was first conducted in 12 (public and private sector) universities among undergraduate pharmacy students (UGPS) (n = 414) irrespective of their study year through a validated questionnaire, and the insights of pharmacy teachers were taken through in-depth semi-structured interviews in the second phase. For the quantitative data, different statistical methods were used, and data were presented in tabulated form, whereas inductive thematic interpretation was used to categorize themes and derive conclusions from qualitative evidence.

Results: The majority of the students were males (n = 223, 54%) with the mean age group 19–23 years, and 20 faculty members were interviewed with a mean duration of 15 min. Students have good knowledge about antibiotics use and the majority purchased antibiotics through prescription (n = 277, 66.9%) during the last month and strongly agreed to stop unnecessary household storage (n = 183 44.2%). Most of the students have heard the terminologies related to antimicrobial resistance through social media while unaware (n = 104, 25.1%) of a Pakistan national action plan against AMR (antimicrobial resistance). Overall, respondents have a somewhat good understanding of the ABR. Regular use of antibiotics without consultation of a physician can lead to ABR and some wrong answers were observed (162, 39.1%; p > 0.05). The majority of the students (n = 198, 47.8%) and teachers believe that the current pharmacy syllabus must be swiftly updated with the new subjects related to ABR and AMS (antimicrobial stewardship) in Pakistan. The UGPS have emphasized (n = 220, 53.1%; Median = 1, IQR = 2) establishing a link between academia and hospitals. The ABR issue has been highlighted by pharmacy faculty members, who have urged students to take practical efforts toward ABR and AMS knowledge.

Conclusion: The UGPS knowledge related to ABR and AMS must be updated. Students at the undergraduate level must get training in order to encourage the sensible use of antibiotics. Courses on ABR and AMS should be included in present pharmacy curricula.

Retrospective Analysis of Antimicrobial Susceptibility of Uropathogens Isolated from Pediatric Patients in Tertiary Hospital at Al-Baha Region, Saudi Arabia

Introduction: Prompt diagnosis and initiation of treatment are essential in preventing long-term renal scarring. However, increasing antibiotic resistance may delay the initiation of appropriate therapy. Methodology: A retrospective chart review was performed for patients admitted to the pediatric department with urinary tract infection (UTI) diagnosis in a large tertiary care hospital in Al Baha, Saudi Arabia, from May 2017 to April 2018. The study included children of both sexes under the age of 14 years. Results: Out of 118 urinary bacterial samples, Escherichia coli was the main etiologic agent in the community- and hospital-acquired infections. The infection rate was higher in girls (68.64%) than in boys (31.36%). The commonest isolates were Escherichia coli (44.07%), extended-spectrum beta-lactamase-producing Escherichia coli (11.86%), Klebsiella pneumoniae (9.32%), Enterococcus faecalis (7.63%), methicillin-resistant Staphylococcus epidermidis (4.24%), and coagulase-negative Staphylococci (3.39%). The current study demonstrates that nitrofurantoin (19%) was the most commonly prescribed medication in the inpatient and outpatient departments, followed by trimethoprim/sulfamethoxazole (16%), amoxicillin/clavulanic acid (15%), cefuroxime (10%), azithromycin (8%), ceftriaxone (7%), and ciprofloxacin (4%), while amikacin, amoxicillin, ampicillin, cefepime, imipenem, phenoxymethylpenicillin were prescribed less commonly due to the high resistance rate. Conclusion: The microbial culture and sensitivity of the isolates from urine samples should be routine before starting antimicrobial therapy. Current knowledge of the antibiotic susceptibility patterns of uropathogens in specific geographical locations is essential for choosing an appropriate empirical antimicrobial treatment rather than reliance on recommended guidelines.

Monitoring Antibiotic Use in Public Health Care Facilities of South Indian Union Territory: A Step to Promote Rational Use of Antibiotics

Introduction

Antimicrobial resistance is a serious problem to solve for the public health authorities at the global level, particularly in developing countries like India. One of the possible reasons for antimicrobial resistance could be the inappropriate or overuse of antibiotics. The Indian government started the National Action Plan on Antimicrobial Resistance to promote rational use of antibiotics in our country. This study was conducted with the objective to monitor antibiotic use in public health facilities of Puducherry which is a union territory of south India.

Methods

Total 900 prescriptions were prospectively collected from the 10 public health facilities (nine primary health centres and one outpatient department of tertiary care hospital) over the period of one year to analyse antibiotic use. 

Results

We found that 36.66 % of prescriptions contained at least one antibiotic. Our result shows that antibiotics were more commonly prescribed from the access category. Upper respiratory tract infections was the most common indication for which antibiotic was prescribed in primary health centres. In the tertiary care teaching hospital, half of the antibiotics were prescribed for cough, followed by pharyngitis (20 %).

Conclusions

A high proportion of antibiotics were prescribed for viral infections. Using antibiotics unnecessary can increase the cost of treatment as well as risk of antibiotic resistance. The Department of Medical Services, Puducherry should take initiative to ensure the successful implantation of the National Action Plan on Antimicrobial Resistance. Data of this study can be used to provide educational intervention for all drug stake holders such as physicians, pharmacists and policy makers to promote rational use of antibiotics.