Spread Of Antibiotic Resistance Research Articles

Subinhibitory antibiotic concentrations promote the horizontal transfer of plasmid-borne resistance genes from Klebsiellae pneumoniae to Escherichia coli.

Horizontal gene transfer plays an important role in the spread of antibiotic resistance, in which plasmid-mediated conjugation transfer is the most important mechanism. While sub-minimal inhibitory concentrations (sub-MIC) of antibiotics could promote conjugation frequency, the mechanism by which sub-MIC levels of antibiotics affect conjugation frequency is not clear. Here, we used Klebsiella pneumoniae SW1780 carrying the multi-drug resistance plasmid pSW1780-KPC as the donor strain, to investigate the effects of sub-MICs of meropenem (MEM), ciprofloxacin (CIP), cefotaxime (CTX), and amikacin (AK) on conjugational transfer of pSW1780-KPC from SW1780 to Escherichia coli J53. Our results showed that the transfer frequencies increased significantly by treating SW1780 strain with sub-MIC levels of MEM, CIP, CTX and AK. Transfer frequencies at sub-MIC conditions in a Galleria mellonella were significantly higher than in vitro. To investigate gene expression and metabolic effects, RT-qPCR and LC-MS-based metabolome sequencing were performed. Transcript levels of T4SS genes virB1, virB2, virB4, virB8, and conjugation-related genes traB, traK, traE, and traL were significantly upregulated by exposure to sub-MICs of MEM, CIP, CTX, and AK. Metabolome sequencing revealed nine differentially regulated metabolites. Our findings are an early warning for a wide assessment of the roles of sub-MIC levels of antibiotics in the spread of antibiotic resistance.

Antibiotic Stewardship and Its Impact on Antibiotic Use at The Child Health Directorate of A Teaching Hospital In Ghana

Purpose: The study was intended to ascertain the existence of an antibiotic stewardship programme at the Child Health Directorate of Komfo Anokye Teaching Hospital (KATH) and assess the knowledge of health professionals about the importance of the antimicrobial stewardship programme. Again, it sort to assess the experience of participants with pharmacotherapy of infections and patient outcomes with generic and innovative brands of antibiotics. The third was to assess reporting on adverse reactions and storage conditions of the antibiotics.
 Design/Methodology/ Approach: This was a cross-sectional study involving health professionals who participated in the provision of infectious disease management services. 
 Findings: Eighty-eight (88) professionals were involved in the study, comprising nurses (n=51), medical doctors (n=21), pharmacists (n=8), biomedical scientists (n=5) and public health officers (n=3). No antibiotic stewardship programme existed. However, there was a protocol for antibiotic use that was not strictly adhered to. About 60 % of the participants had knowledge of the antibiotic stewardship programme and affirmed its importance. The majority (75 %, n=66) reported treatment failure with generic brands of antibiotics compared to innovator brands. Thirty-four percent of the participants (n=30) reported adverse drug reactions (ADRs) on antibiotic therapy to superiors instead of filling out ADR forms. Antibiotics were kept in inpatient bedside cabinets with no thermometers to monitor the storage temperature conditions.
 Research Limitations: The study was done in one Directorate in the hospital and thus cannot be generalized to reflect the situation in all teaching hospitals in Ghana.
 Practical implication: The evidence obtained highlighted the need for pragmatic antimicrobial stewardship (AMS) at the directorate to help optimize the management of childhood infections and minimize the emergence and spread of antibiotic resistance.
 Originality/Value. This was an original project designed to generate evidence to inform interventions to promote the responsible use of antimicrobials in children.

Nutrient Availability and Biofilm Polysaccharide Shape the Bacillaene-Dependent Antagonism of Bacillus subtilis against Salmonella Typhimurium.

Salmonella enterica is one of the most common foodborne pathogens and, due to the spread of antibiotic resistance, new antimicrobial strategies are urgently needed to control it. In this study, we explored the probiotic potential of Bacillus subtilis PS-216 and elucidated the mechanisms that underlie the interactions between this soil isolate and the model pathogenic strain S. Typhimurium SL1344. The results reveal that B. subtilis PS-216 inhibits the growth and biofilm formation of S. Typhimurium through the production of the pks cluster-dependent polyketide bacillaene. The presence of S. Typhimurium enhanced the activity of the PpksC promoter that controls bacillaene production, suggesting that B. subtilis senses and responds to Salmonella. The level of Salmonella inhibition, overall PpksC activity, and PpksC induction by Salmonella were all higher in nutrient-rich conditions than in nutrient-depleted conditions. Although eliminating the extracellular polysaccharide production of B. subtilis via deletion of the epsA-O operon had no significant effect on inhibitory activity against Salmonella in nutrient-rich conditions, this deletion mutant showed an enhanced antagonism against Salmonella in nutrient-depleted conditions, revealing an intricate relationship between exopolysaccharide production, nutrient availability, and bacillaene synthesis. Overall, this work provides evidence on the regulatory role of nutrient availability, sensing of the competitor, and EpsA-O polysaccharide in the social outcome of bacillaene-dependent competition between B. subtilis and S. Typhimurium. IMPORTANCE Probiotic bacteria represent an alternative for controlling foodborne disease caused by Salmonella enterica, which constitutes a serious concern during food production due to its antibiotic resistance and resilience to environmental stress. Bacillus subtilis is gaining popularity as a probiotic, but its behavior in biofilms with pathogens such as Salmonella remains to be elucidated. Here, we show that the antagonism of B. subtilis is mediated by the polyketide bacillaene and that the production of bacillaene is a highly dynamic trait which depends on environmental factors such as nutrient availability and the presence of competitors. Moreover, the production of extracellular polysaccharides by B. subtilis further alters the influence of these factors. Hence, this work highlights the inhibitory effect of B. subtilis, which is condition-dependent, and the importance of evaluating probiotic strains under conditions relevant to the intended use.

Knowledge, Attitude, and Behavior about Antimicrobial Use and Resistance among Medical, Nursing and Pharmacy Students in Jordan: A Cross Sectional Study.

The present study aimed to survey medical, nursing and pharmacy students' knowledge, attitude and practice regarding antimicrobial use and resistance. Additionally, the study assessed the teaching and assessment activities received regarding antibiotic use. A cross sectional online survey was distributed to undergraduate students currently in clinical studies in their degree program. A total of 716 medicine, nursing and pharmacy undergraduate students were included. Respondents scored more than 76% on knowledge on effective use, unnecessary use and associated side effects of antibiotics, and 65.2% regarding knowledge on the spread of antibiotic resistance. Some participants (21.0%) agreed or strongly agreed that there has been good promotion of prudent antimicrobial use. Students were aware (13.1%), unaware (29.1%), or unsure (57.8%) that there is a national action plan relating to antimicrobial resistance. A total of 62.8% of the respondents strongly agreed or agreed that they have a key role in helping control antibiotic resistance. Participants reported that they require more information about resistance to antibiotics (53.9%), medical conditions for which antibiotics are used (51.7%) and how to use antibiotics (51.0%). Discussion of clinical cases and vignettes and small group teaching were reported as very useful or useful teaching strategies (79.9% and 74.2%, respectively). The findings from this study determined the current situation in relation to education on prudent antimicrobial use for undergraduates and highlighted areas for informing better curriculum design.

The inactivation of antibiotic-resistant bacteria and the damage of antibiotic-resistant genes using an electrified carbon nanotube membrane-NaClO system

The inactivation of antibiotic-resistant bacteria (ARB) and damage of antibiotic resistance genes (ARGs) in aquatic environments have become major concerns worldwide in controlling the rapid spread of antibiotic resistance. In this study, an electrified carbon nanotube membrane (ECM) was combined with chlorine disinfection (denoted as ECM-NaClO system) to treat the sulphonamide resistance bacteria (HLS-6) and tetracycline resistance bacteria (TOP-10F) in water samples. The ECM-NaClO system effectively inactivated the HLS-6 and TOP-10F by damaging the cell membrane and increasing amounts of intracellular reactive oxygen species (ROS). In addition, the absolute abundances of the sulphonamide resistance gene (sul1) and tetracycline resistance gene (tetA) in the effluent decreased by 3.5 and 1.7 logs, respectively. Furthermore, the absolute abundance of mobile genetic elements (intI1) decreased by 4.1–4.7 logs. The ROS probe compound degradation and quenching experiments revealed that the •OH generated via the 2-electron oxygen reduction reaction played a dominant role in the damage of sul1 gene, while •O2– generated through the activation of NaClO was a key contributor to the damage of tetA gene. Hence, the ECM-NaClO system is a potential method to inactivate ARB and damage ARGs in water and sewage treatment plants.

Knowledge, attitudes, and behavior regarding antibiotics, antibiotic use, and antibiotic resistance in students and health care professionals of the district of Barranquilla (Colombia): A cross-sectional survey

ObjectiveTo evaluate the knowledge, attitudes and behavior regarding antibiotics, use of antibiotics, and antibiotic resistance in students and health care professionals of the district of Barranquilla, Colombia. Study designDescriptive, cross-sectional. MethodsA sample of 399 respondents was selected, that included health professionals and medical students from 12 health institutions in the district of Barranquilla (Colombia), using an established stratified sampling method. Each of the respondent professionals completed a survey that included 43 items in the Likert scale. A descriptive analysis of the study variables was performed using the software SPSS version 25. ResultsMost of the respondents were women (64.4%), aged between 26 and 35 years (47.6%); 28.8% were nurses and 26.1% general practitioners, with ≤10 years of professional experience (63.4%). Overall, the survey revealed that the participants had considerable knowledge about antibiotic use (89.5%–98% correct answers) and the spread of antibiotic resistance (67.4%–89% correct answers). Approximately 74% of the respondents agreed or fully agreed with the questions related to the management of infections and the provision of advice. ConclusionsThe present study revealed that most of the health care professionals surveyed had a good knowledge about antibiotic use, although strategies must be developed to strengthen knowledge regarding the spread of antibiotic resistance. Likewise, it is important to identify opportunities for improvement related with access to the guidelines and/or materials necessary to treat infections and to provide advice on antibiotic use and antibiotic resistance.

Knowledge, Attitude and Practice of Pharmacy Professionals Against Dispensing Antibiotics Without Prescription in Ethiopia.

Antibiotic resistance is a global public health threat that warrants immediate intervention. Dispensing of antibiotics without prescription (DAWP), is an inappropriate practice that contributes significantly to the emergence and spread of antibiotic resistance. The current study aimed to assess the knowledge, attitude and practice of community pharmacists and pharmacy assistants towards DAWP. A cross-sectional study was conducted, and data was collected from community pharmacists and pharmacy assistants during the eighth national pharmacist's day, which was held on December 4, 2021, in Addis Ababa, Ethiopia. A pre-tested self-administered questionnaire comprise of four sections (socio-demographic characteristics, and knowledge, attitude and practice towards DAWP) was used. The data was analyzed using SPSS version 26 and descriptive statistics (mean, percentage, standard deviation) were computed. Binary logistic regression was used to predict determinates of DAWP. A total of 175 community pharmacy professional were invited in the study, with 158 (111 pharmacists and 47 pharmacy assistants) completing the survey for 90.3% response rate. Most of the participants (86.7%) were aware that DAWP is illegal in Ethiopia. Despite their knowledge, the extent of DAWP was found to be 67.7%. The most common reason given by study participants for DAWP was that most patients do not want to consult prescribers unless the infection appears serious (53.2%). Pharmacy professionals with educational background of masters and above (AOR= 0.354, 95% CI: 0.013-0.744, P= 0.045), and with two to five years of working in community pharmacy (AOR= 0.745, 95% CI: 0.595-0.933, P= 0.010) had a lower tendency to DAWP, respectively. Despite majority of pharmacy professional are aware that DAWP is illegal and contributes to antibiotic resistance, they commonly DAWP for common cold and diarrheal diseases. Strict enforcement of existing antibiotic supply policies, and ongoing educational support for community pharmacy professionals on the judicious use of antibiotics is recommended.

Solution characterization of the dynamic conjugative entry exclusion protein TraG.

The R100 plasmid and the secretion system it encodes are representative of F-like conjugative type IV secretion systems for the transmission of mobile DNA elements in gram-negative bacteria, serving as a major contributor to the spread of antibiotic resistance in bacterial pathogens. The TraG protein of F-like systems consists of a membrane-bound N-terminal domain and a periplasmic C-terminal domain, denoted TraG*. TraG* is essential in preventing redundant DNA transfer through a process termed entry exclusion. In the donor cell, it interacts with TraN to facilitate mating pair stabilization; however, if a mating pore forms between bacteria with identical plasmids, TraG* interacts with its cognate TraS in the inner membrane of the recipient bacterium to prevent redundant donor-donor conjugation. Structural studies of TraG* from the R100 plasmid have revealed the presence of a dynamic region between the N- and C-terminal domains of TraG. Thermofluor, circular dichroism, collision-induced unfolding-mass spectrometry, and size exclusion chromatography linked to multiangle light scattering and small angle x-ray scattering experiments indicated an N-terminal truncation mutant displayed higher stability and less disordered content relative to full-length TraG*. The 45 N-terminal residues of TraG* are hypothesized to serve as part of a flexible linker between the two independently functioning domains.

Molecular Epidemiology of Neonatal-Associated Staphylococcus haemolyticus Reveals Endemic Outbreak.

Staphylococcus haemolyticus is a major cause of late-onset sepsis in neonates, and endemic clones are often multidrug-resistant. The bacteria can also act as a genetic reservoir for more pathogenic bacteria. Molecular epidemiology is important in understanding bacterial pathogenicity and preventing infection. To describe the molecular epidemiology of S. haemolyticus isolated from neonatal blood cultures at a Swedish neonatal intensive care unit (NICU) over 4 decades, including antibiotic resistance genes (ARGs), virulence factors, and comparison to international isolates. Isolates were whole-genome sequenced, and single nucleotide polymorphisms in the core genome were used to map the relatedness. The occurrence of previously described ARGs and virulence genes were investigated. Disc diffusion and gradient tests were used to determine phenotypic resistance. The results revealed a clonal outbreak of S. haemolyticus at this NICU during the 1990s. Multidrug resistance was present in 28 (82%) of all isolates and concomitant resistance to aminoglycoside and methicillin occurred in 27 (79%). No isolates were vancomycin resistant. Genes encoding ARGs and virulence factors occurred frequently. The isolates in the outbreak were more homogenous in their genotypic and phenotypic patterns. Genotypic and phenotypic resistance combinations were consistent. Pathogenic traits previously described in S. haemolyticus occurred frequently in the present isolates, perhaps due to the hospital selection pressure resulting in epidemiological success. The clonal outbreak revealed by this study emphasizes the importance of adhering to hygiene procedures in order to prevent future endemic outbreaks. IMPORTANCE This study investigated the relatedness of Staphylococcus haemolyticus isolated from neonatal blood and revealed a clonal outbreak in the 1990s at a Swedish neonatal intensive care unit. The outbreak clone has earlier been isolated in Japan and Norway. Virulence and antibiotic resistance genes previously associated with clinical S. haemolyticus were frequently occuring in the present study as well. The majority of the isolates were multidrug-resistant. These traits should be considered important for S. haemolyticus epidemiological success and are probably caused by the hospital selection pressure. Thus, this study emphasizes the importance of restrictive antibiotic use and following the hygiene procedures, to prevent further antibiotic resistance spread and future endemic outbreaks.

Evaluation of antibacterial activity of five biocides and the synergistic effect of biocide/EDTA combinations on biofilm-producing and non-producing Stenotrophomonas maltophilia strains isolated from clinical specimens in Iran

BackgroundThe overuse of biocides in healthcare-facilities poses risk for emergence and spread of antibiotic resistance among nosocomial pathogens. Hospital-acquired infections due to S. maltophilia have been increased in the recent years and with its various resistance mechanisms contribute to patient morbidity and mortality in hospitals. The current study aimed to evaluate the susceptibility of biofilm-producing and non-producing S. maltophilia clinical isolates to five commonly used hospital biocides, alone and in combination with EDTA to examine the synergistic effect of combining EDTA on the bactericidal activity of them by microbroth dilution method. As well as the frequency of efflux genes encoding resistance to biocides among isolates. This study also intended to assess the effect of exposure of S. maltophilia isolates to sub-inhibitory concentrations of sodium hypochlorite upon the antimicrobial susceptibility patterns.ResultsBased on minimum inhibitory and bactericidal concentrations of biocides sodium hypochlorite 5% (w/v) and ethyl alcohol 70% (v/v) were the strongest and weakest biocides against S. maltophilia isolates, respectively. The combination of EDTA with biocides significantly increased the effectiveness of the studied biocides. Exposure to sub-inhibitory concentration of sodium hypochlorite showed a significant change in the susceptibility of isolates towards ceftazidime (p = 0.019), ticarcillin/clavulanate (p = 0.009), and chloramphenicol (p = 0.028). As well as among the isolates examined, 94 (95%) were able to produce biofilm. The frequency of sugE1 resistance genes was found in 90.7% of our clinical S. maltophilia isolates. None of the isolates carried qacE and qacEΔ1 gene.ConclusionsThe current study recommended that using the mixture of biocides with EDTA can be effective in reducing nosocomial infections. Also, this study demonstrated that exposure to sub-inhibitory concentrations of sodium hypochlorite leads to reduced antibiotic susceptibility and development of multidrug-resistant S. maltophilia strains.

Study of the monoglycerides features as a promising alternative to antibiotics in feeding broiler chickens

The spreading of antibiotic resistance in the modern world results from the application of uncontrolled and excessively intensive antibiotics for treating human infectious diseases and their use as growth stimulants in animal farming. In some economically developed countries, restrictions on the use of antibiotics are already applied in order to prevent the generation of resistant strains of microorganisms. An essential component of such means is antibiotic-free strategies in animal farming. Recently, strategies based on the alternative to both antimicrobials and growth promoters have been proposed, including probiotics, prebiotics, synbiotics, enzymes, and organic acids. Short-chain fatty acids and monoglycerides based on them are considered a promising alternatives to antimicrobial agents for poultry farming. However, the effects of these compounds on innate immunity and cytokine production in the intestinal system remain undiscovered. The experiment was carried out using two groups of Cobb 500 cross broilers in the conditions of an industrial poultry farm. The broiler chickens of the research group were exposed to a monoglyceride mixture with С3, С4, С8–С10 fatty acids from 1 to 7 days of life and 16 to 22 days of life at a dose of 0.5 l of the mixture per ton of water. On the 31-st day of life, productive parameters were evaluated, and five birds were selected from each group. The fragments of the duodenum, caecum, and rectum with contents were taken from the bird. In the presented study, the content of interferon-α in the tissue of the small intestine of broiler chickens under the conditions of drinking monoglyceride was studied. To evaluate the beneficial effect of monoglyceride, the state of the microbiome and productive indicators were determined. The study showed that the monoglyceride induces a statistically significant increase in the content of enterococcus in the duodenum, suppresses the growth of staphylococcus, and increases the production of interferon-α. Moreover, average daily weight gain relative to controls was almost 2% greater in monoglyceride-treated chicks. Thus, preservation of the state of microbiota and moderate stimulation of interferon-α production can be essential components of the multidirectional protective effect of monoglycerides and fatty acids.

Patient expectations do matter - experimental evidence on antibiotic prescribing decisions

Abstract Inappropriate prescription of antibiotics remains a major contributor to the global antimicrobial resistance crisis despite clear linkages between antibiotic utilization and resistance spread. This study aims to better understand the simultaneous and independent effect of previous prescription behavior, patient expectation, and clinical uncertainty on antibiotic prescribing. This discrete choice experiment was embedded within a routine organizational climate survey administered to all physicians working in the Tuscany healthcare system administered between Nov 11 and Nov 20, 2019 (Qualtrics). Participants were provided with a patient encounter vignette and subsequently asked to in which of two alternatives they were more likely to prescribe antibiotics. The two alternatives varied in levels of clinical uncertainty, patient expectations, and the physician’s past behavior. We fitted a conditional logistic regression model. Respondents included 1,436 hospital-based physicians, of which 52% were female, 78% practiced in a general hospital setting, and 33% were between the ages of 50 and 59. Results show that the odds of prescribing antibiotics decrease when a patient requests it (OR = 0.80, 95%CI [0.72,0.89]) and increase when the physician has prescribed antibiotics to a patient under similar circumstances previously (OR = 1.15, 95%CI [1.03,1.27]). We found no significant effect of clinical uncertainty on the odds of prescribing antibiotics (OR = 0.96, 95%CI [0.87, 1.07]). We show that patient expectation has a significant negative association with antibiotic prescribing among hospital-based physicians. Our findings inform the design of antibiotic stewardship programs in Tuscany and highlight the importance of cultural context in shaping the physician’s disposition when confronted with patient expectations. We suggest shared decision-making to improve prudent prescribing without compromising on patient satisfaction. Key messages • Health administrators should address patient expectations when designing hospital antibiotic stewardship programs. • Physicians’ past prescribing behaviour influences antibiotic prescribing decisions and should be considered during intervention design.

Ecological Responses of Maize Rhizosphere to Antibiotics Entering the Agricultural System in an Area with High Arsenicals Geological Background.

Metal(loid)s can promote the spread and enrichment of antibiotic resistance in the environmental ecosystem through a co-selection effect. Little is known about the ecological effects of entering antibiotics into the environment with long-term metal(loid)s’ resistance profiles. Here, cow manure containing oxytetracycline (OTC) or sulfadiazine (SA) at four concentrations (0 (as control), 1, 10, and 100 mg/kg) was loaded to a maize cropping system in an area with high a arsenicals geological background. Results showed that exogenous antibiotics entering significantly changed the nutrient conditions, such as the concentration of nitrate nitrogen, ammonium nitrogen, and available phosphorus in the maize rhizosphere soil, while total arsenic and metals did not display any differences in antibiotic treatments compared with control. Antibiotics exposure significantly influenced nitrate and nitrite reductase activities to reflect the inhibition of denitrification rates but did not affect the soil urease and acid phosphatase activities. OTC treatment also did not change soil dehydrogenase activities, while SA treatment posed promotion effects, showing a tendency to increase with exposure concentration. Both the tested antibiotics (OTC and SA) decreased the concentration of arsenite and arsenate in rhizosphere soil, but the inhibition effects of the former were higher than that of the latter. Moreover, antibiotic treatment impacted arsenite and arsenate levels in maize root tissue, with positive effects on arsenite and negative effects on arsenate. As a result, both OTC and SA treatments significantly increased bioconcentration factors and showed a tendency to first increase and then decrease with increasing concentration. In addition, the treatments decreased translocation capacity of arsenic from roots to shoots and showed a tendency to increase translocation factors with increasing concentration. Microbial communities with arsenic-resistance profiles may also be resistant to antibiotics entering.

Detection and Quantification of Antimicrobial-Resistant Cells in Aquatic Environments by Bioorthogonal Noncanonical Amino Acid Tagging.

Aquatic environments are important reservoirs of antibiotic wastes, antibiotic resistance genes, and bacteria, enabling the persistence and proliferation of antibiotic resistance in different bacterial populations. To prevent the spread of antibiotic resistance, effective approaches to detect antimicrobial susceptibility in aquatic environments are highly desired. In this work, we adopt a metabolism-based bioorthogonal noncanonical amino acid tagging (BONCAT) method to detect, visualize, and quantify active antimicrobial-resistant bacteria in water samples by exploiting the differences in bacterial metabolic responses to antibiotics. The BONCAT approach can be applied to rapidly detect bacterial resistance to multiple antibiotics within 20 min of incubation, regardless of whether they act on proteins or DNA. In addition, the combination of BONCAT with the microscope enables the intuitive characterization of antibiotic-resistant bacteria in mixed systems at single-cell resolution. Furthermore, BONCAT coupled with flow cytometry exhibits good performance in determining bacterial resistance ratios to chloramphenicol and population heterogeneity in hospital wastewater samples. In addition, this approach is also effective in detecting antibiotic-resistant bacteria in natural water samples. Therefore, such a simple, fast, and efficient BONCAT-based approach will be valuable in monitoring the increase and spread of antibiotic resistance within natural and engineered aquatic environments.

Neutral (Fe3+-NTA) and acidic (Fe2+) pH solar photo-Fenton Vs chlorination: Effective urban wastewater disinfection does not mean control of antibiotic resistance

Solar photo-Fenton (SPF) process in raceway pond reactors was investigated at neutral pH by Fe3+-NTA complex and at acidic pH by Fe2+and compared with chlorination process in E. coli inactivation, antibiotic Trimethoprim (TMP) and antibiotic resistance genes (ARGs) removal from secondary treated urban wastewater. E. coli inactivation below the detection limit (DL) was achieved in less than 15 min under acidic pH. At neutral pH, the DL was reached in 60 min treatment with 0.2 mM of Fe3+-NTA and 4.41 mM of H2O2. In contrast, the removal of TMP (50 µg/L) by SPF was higher at neutral pH (95%) compared to the acidic pH condition (80%). Although chlorination (10 mg/L chlorine dose) inactivated E. coli below the DL between 2.5 and 5 min, no degradation of TMP was observed. Target ARGs (quinolone, sulphonamides, β-lactams, cephalosporins and tetracycline classes), class 1 integron integrase (intI1) and the 16 S rRNA gene, were only slightly removed under realistic conditions (32% and 23% as max removals of intl1 by chlorination and SPF at acidic pH, respectively) and may not effectively control the potential of antibiotic resistant spread under the mild oxidation conditions investigated in this study.

Draft Genome Sequences of Multidrug-Resistant Escherichia coli Isolated from River Water.

The spread of antibiotic resistance poses a critical challenge worldwide. Contaminated environments can become reservoirs, spreading antibiotic-resistant bacteria and genetic determinants of resistance to humans directly or indirectly. Here, we report the draft genome sequence, the resistome, virulence genes, and sequence types of seven multidrug-resistant Escherichia coli strains isolated from river water.

Survival and Virulence Potential of Drug-Resistant E. coli in Simulated Gut Conditions and Antibiotic Challenge.

The gut forms a vital niche for the survival and replication of drug-resistant E. coli; however, the role of gut conditions on drug-resistant and sensitive E. coli is not clearly understood. The study aims to understand the effect of in vitro gut conditions on the spread of antibiotic resistance among E. coli and their ability to adapt to gut conditions. In this study, a multidrug-resistant (J51) and a sensitive (J254) E. coli isolate were exposed to a series of in vitro gut conditions and their growth pattern, virulence gene expression and invasion ability were studied. Further, the effect of antibiotic under in vitro gut conditions was also studied. Bile significantly affected the growth of the isolates, and the addition of iron chelator extended the lag phase of the sensitive isolate. Each in vitro gut condition had a differential effect on the expression of virulence genes in both the isolates. Further, the resistant isolate could adhere to and invade Caco2 cell lines better than the sensitive isolate. Most of the downregulated genes showed increased expression upon ciprofloxacin shock under in vitro gut conditions. The transcriptomics study revealed that exposure to bile, led to the downregulation of genes involved in different metabolic pathways. Further downregulation of metabolic pathways on ciprofloxacin shock was also observed. The downregulation of metabolic pathways could be a part of the global response played by the bacteria to adapt to harsh conditions. Reverting these fluctuated pathways could prove to be a novel strategy in combating AMR threat. Overall, bile, in high and low temperature conditions, showed a significant effect on modulating virulence gene expression on the antibiotic challenge. Thus, it is essential to consider the impact of gut conditions on gut pathogens, such as E. coli, before prescribing antimicrobial therapy during infection.

Long-Read Whole Genome Sequencing Elucidates the Mechanisms of Amikacin Resistance in Multidrug-Resistant Klebsiella pneumoniae Isolates Obtained from COVID-19 Patients

Klebsiella pneumoniae is a Gram-negative, encapsulated, non-motile bacterium, which represents a global challenge to public health as one of the major causes of healthcare-associated infections worldwide. In the recent decade, the World Health Organization (WHO) noticed a critically increasing rate of carbapenem-resistant K. pneumoniae occurrence in hospitals. The situation with extended-spectrum beta-lactamase (ESBL) producing bacteria further worsened during the COVID-19 pandemic, due to an increasing number of patients in intensive care units (ICU) and extensive, while often inappropriate, use of antibiotics including carbapenems. In order to elucidate the ways and mechanisms of antibiotic resistance spreading within the K. pneumoniae population, whole genome sequencing (WGS) seems to be a promising approach, and long-read sequencing is especially useful for the investigation of mobile genetic elements carrying antibiotic resistance genes, such as plasmids. We have performed short- and long read sequencing of three carbapenem-resistant K. pneumoniae isolates obtained from COVID-19 patients in a dedicated ICU of a multipurpose medical center, which belonged to the same clone according to cgMLST analysis, in order to understand the differences in their resistance profiles. We have revealed the presence of a small plasmid carrying aph(3′)-VIa gene providing resistance to amikacin in one of these isolates, which corresponded perfectly to its phenotypic resistance profile. We believe that the results obtained will facilitate further elucidating of antibiotic resistance mechanisms for this important pathogen, and highlight the need for continuous genomic epidemiology surveillance of clinical K. pneumoniae isolates.

Antibiotic combinations reduce Staphylococcus aureus clearance.

The spread of antibiotic resistance is attracting increased attention to combination-based treatments. Although drug combinations have been studied extensively for their effects on bacterial growth1–11, much less is known about their effects on bacterial long-term clearance, especially at cidal, clinically relevant concentrations12–14. Here, using en masse microplating and automated image analysis, we systematically quantify Staphylococcus aureus survival during prolonged exposure to pairwise and higher-order cidal drug combinations. By quantifying growth inhibition, early killing and longer-term population clearance by all pairs of 14 antibiotics, we find that clearance interactions are qualitatively different, often showing reciprocal suppression whereby the efficacy of the drug mixture is weaker than any of the individual drugs alone. Furthermore, in contrast to growth inhibition6–10 and early killing, clearance efficacy decreases rather than increases as more drugs are added. However, specific drugs targeting non-growing persisters15–17 circumvent these suppressive effects. Competition experiments show that reciprocal suppressive drug combinations select against resistance to any of the individual drugs, even counteracting methicillin-resistant Staphylococcus aureus both in vitro and in a Galleria mellonella larva model. As a consequence, adding a β-lactamase inhibitor that is commonly used to potentiate treatment against β-lactam-resistant strains can reduce rather than increase treatment efficacy. Together, these results underscore the importance of systematic mapping the long-term clearance efficacy of drug combinations for designing more-effective, resistance-proof multidrug regimes.

The Public Health Consequences of Substandard Medicines in Nigeria

Introduction: Poor-quality medicines are a serious public health issue, especially in emerging economies and developing countries, and can have a significant impact on the national clinical and economic burden. Although much attention has been focused on the increasing availability of intentionally falsified drugs, substandard medicines are also reaching patients as a result of poor manufacturing and quality-control practices in the manufacture of genuine drugs (either branded or generic). Substandard medicines are common and pose a health risk because they can inadvertently lead to healthcare failures such as antibiotic resistance and disease spread within a community, as well as death or additional illness in individuals. Conclusion: The potential solutions to substandard manufacturing practices are also discussed. To ensure that only drugs of acceptable quality reach the patient, governments, drug manufacturers, charities, and healthcare providers must work together.