Antibiotic Treatment Options Research Articles

Mycoplasma pneumoniae: not a typical respiratory pathogen.

Mycoplasma pneumoniae is a leading cause of community-acquired pneumonia among school-aged children and young adults. Infections occur throughout the year but tend to surge during winter months across Europe. A characteristic epidemic cycle, where a substantial surge in the number of infections occurs, is seen approximately every 1-4 years and hypothesized to be driven by changes in immunity and a shift in circulating variants. Once thought to be an organism of low virulence, it has now been found to possess several virulence factors, including toxin production, biofilm formation and evasion of antibody-mediated immunity. The lack of a cell wall and reduced metabolic pathways limit the options for antibiotic treatment. Acquired macrolide resistance is a growing concern, with >80% of cases in China being macrolide-resistant. Although efforts have been made to develop a vaccine, there are still substantial hurdles to overcome in relation to vaccine-enhanced disease, which results from an inappropriate immune response among vaccinated individuals.

Polymeric Antibiotic Beads for Canine Osteomyelitis: Advancing Localized Antibiotic Treatment with Enhanced Efficacy and Minimized Side Effects

Antibiotic beads represent a compelling treatment method for the treatment and prevention of canine osteomyelitis, as they provide localized antibiotic concentrations at the infection site with minimal systemic toxicity. The therapeutic efficacy of these beads has been demonstrated, highlighting their potential as a valuable local antibiotic therapy. In particular, the introduction of vancomycin - polymethylmethacrylate (PMMA) beads is highlighted as a promising new form of local antibiotic therapy. This article focuses on the use of antibiotic-impregnated beads to treat localized bacterial infections in the bones and joints of canines. Typically composed of poly(lactic-co-glycolic acid) (PLGA) or polymethylmethacrylate (PMMA), these beads contain antibiotics such as vancomycin, placed directly into the affected area, providing a high antibiotic concentration at the site of infection. These beads were developed for a slow antibiotic release over time; they ensure a constant protective effect against a broad spectrum of bacteria, demonstrating high efficacy and biocompatibility with the animal's body. This localized antibiotic treatment option offers several advantages over systemic antibiotics, such as reduced side effects and improved efficacy. It could be a promising option for the treatment of bone and joint infections in canines.

General Characteristics and Current State of Antibiotic Resistance in Pediatric Urinary Tract Infection-A Single Center Experience.

We analyzed 210 positive urine cultures identified in 141 pediatric patients admitted to the hospital over a 6-month period. The majority of patients were females (57%) with a median age of 5 years (IQR 12), while male patients revealed a median age of 2 (IQR 7). Most patients originated from urban areas (53%). Only 18 patients (12.76%) were identified with underlying Congenital Anomalies of the Kidney and Urinary Tract (CAKUT). Escherichia Coli was the most frequent pathogen. Increased antibiotic resistance was found in commonly-used antibiotics Ampicillin and Trimethoprim/Sulfamethoxazole, and in the case of patients with CAKUT. Suitable antibiotics for treating a Gram-negative UTI are aminoglycosides, Meropenem, third-generation Cephalosporins, and Nitrofurantoin. Vancomycin upholds efficacy in treating a Gram-positive pediatric UTI. Periodical analysis needs to be performed in order to constantly update clinicians on uropathogenic antibiotic resistance and optimal empirical treatment options.

Silencing of Resistance Mechanism in Vancomycin-Resistance Enterococci Using Antisense RNA of vanA Gene

The World Health Organization has included the problem of antibiotic resistance among the top 10 important health problems in the world. Treatment of infectious diseases has become more difficult due to the spread of antibiotic resistance between bacteria via transposable elements. Vancomycin-resistant enterococci (VRE) are of critical medical and public health importance due to their association with serious nosocomial infections and high risk of death. One of the most important features of VREs is that they have multiple antibiotic resistance and treatment options are reduced. Therefore, new treatment methods are needed. The vanA gene constitutes the building block of the vancomycin resistance mechanism and causes high resistance to vancomycin. In this study, it was aimed to investigate the neutralization of the vancomycin resistance mechanism by creating vanA antisense RNA (asRNA). The vanA positive VRE50 strain in our culture collection which was isolated from the clinical sample, was used to amplify the vanA gene by polymerase chain reaction (PCR). The amplified vanA amplicon was inserted inversely into the pUC19 plasmid by means of the enzyme cutting sites in the primers used. The resulting plasmid was combined with the pAT392 plasmid which can replicate in gram-positive bacteria and a fusion plasmid was created. The fusion plasmid whose orientation was confirmed, was transferred to the wild strain VRE50 by electroporation method. Minimum inhibitory concentration (MIC) values of transformed VRE (tVRE50) and wild type VRE50 strains used as control were determined by the E-Test method. The vancomycin MIC value of the wild type VRE50 strain was determined as 1024 µg/mL and that of the tVRE50 strain was 32 µg/mL and it was determined that the vancomycin resistance of the tVRE50 strain decreased with asRNA (antisense RNA). Antisense RNA technology is an important method for neutralizing the expression of genes. This study showed that neutralization of the vancomycin resistance gene may provide a lower MIC value in a vancomycin-resistant enterococcus strain and lead to increased susceptibility. This new approach provides a new method for VRE treatment by neutralizing the vancomycin resistance mechanism. The result obtained in this study needs to be supported by in vivo tests.

Recommandations françaises 2023 pour le diagnostic et la prise en charge des bursites septiques prépatellaires et olécraniennes

Septic bursitis (SB) is a common condition accounting for one third of all cases of inflammatory bursitis. It is often related to professional activities. Management is heterogeneous and either ambulatory or hospital-based, with no recommendations available. This article presents recommendations for managing patients with septic bursitis gathered by 18 rheumatologists from the French Society for Rheumatology work group on bone and joint infections, 1 infectious diseases specialist, 2 orthopedic surgeons, 1 general practitioner and 1 emergency physician. This group used a literature review and expert opinions to establish 3 general principles and 11 recommendations for managing olecranon and prepatellar SB. The French Health authority (Haute Autorité de santé [HAS]) methodology was used for these recommendations. Designed for rheumatologists, general practitioners, emergency physicians and orthopedic surgeons, they focus on the use of biological tests and imaging in both outpatient and inpatient management. Antibiotic treatment options (drugs and duration) are proposed for both treatment modalities. Finally, surgical indications, non-drug treatments and prevention are covered by specific recommendations.

Synergistic effects of ceftazidime/avibactam combined with meropenem in a murine model of infection with KPC-producing Klebsiella pneumoniae.

The emergence and expansion of carbapenem-resistant Klebsiella pneumoniae infections is a concern due to the lack of 'first-line' antibiotic treatment options. The ceftazidime/avibactam is an important clinical treatment for carbapenem-resistant K. pneumoniae infections but there is an increasing number of cases of treatment failure and drug resistance. Therefore, a potential solution is combination therapies that result in synergistic activity against K. pneumoniae carbapenemase: producing K. pneumoniae (KPC-Kp) isolates and preventing the emergence of KPC mutants resistant to ceftazidime/avibactam are needed in lieu of novel antibiotics. To evaluate their synergistic activity, antibiotic combinations were tested against 26 KPC-Kp strains. Antibiotic resistance profiles, molecular characteristics and virulence genes were investigated by susceptibility testing and whole-genome sequencing. Antibiotic synergy was evaluated by in vitro chequerboard experiments, time-killing curves and dose-response assays. The mouse thigh model was used to confirm antibiotic combination activities in vivo. Additionally, antibiotic combinations were evaluated for their ability to prevent the emergence of ceftazidime/avibactam resistant mutations of blaKPC. The combination of ceftazidime/avibactam plus meropenem showed remarkable synergistic activity against 26 strains and restored susceptibility to both the partnering antibiotics. The significant therapeutic effect of ceftazidime/avibactam combined with meropenem was also confirmed in the mouse model and bacterial loads in the thigh muscle of the combination groups were significantly reduced. Furthermore, ceftazidime/avibactam plus meropenem showed significant activity in preventing the occurrence of resistance mutations. Our results indicated that the combination of ceftazidime/avibactam plus meropenem offers viable therapeutic alternatives in treating serious infections due to KPC-Kp.

Phage therapy in lung infections caused by multidrug-resistant Pseudomonas aeruginosa - A literature review.

Pulmonary infections of patients with cystic fibrosis (CF) or in intensive care units are frequently caused by the Gram-negative opportunistic pathogen Pseudomonas aeruginosa. Since these bacteria are commonly inherently multidrug-resistant (MDR) and hence, antibiotic treatment options are limited, bacteriophages may provide alternative therapeutic and prophylactic measures in the combat of pneumonia caused by P. aeruginosa. This prompted us to perform a comprehensive literature survey of current knowledge regarding effects of phages applied against pulmonary P. aeruginosa infections. Theincluded 23 studies revealed that P. aeruginosa specific phages lyse and eliminate the bacteria even in case of biofilm production in vitro, whereas application to mice and men resulted in mitigated P.aeruginosa induced clinical signs and enhanced survival. Besides distinct host immune responses, no major adverse effects limiting therapeutic and/or prophylactic phage application were noted. However, the immune system and antibiotics generate synergies with phages due to the mutable sensitivity of P.aeruginosa. In conclusion, results summarized in this review provide evidence that phages constitute promising alternative treatment options for lung infections caused by MDR P. aeruginosa. Further studies are needed, however, to underscore the efficacy and safety aspects of phages application to infected patients including immune-compromised individuals.

Identification and evolution of ICE-PmuST394: a novel integrative conjugative element in Pasteurella multocida ST394.

The emergence of macrolide and tetracycline resistance within Pasteurella multocida isolated from feedlot cattle and the dominance of ST394 in Australia was reported recently. To establish the genetic context of the resistance genes in P. multocida 17BRD-035, the ST394 reference genome, and conduct a molecular risk assessment of their ability to disperse laterally. A bioinformatic analysis of the P. multocida 17BRD-035 genome was conducted to determine if integrative conjugative elements (ICEs) carrying resistance genes, which hamper antibiotic treatment options locally, are in circulation in Australian feedlots. A novel element, ICE-PmuST394, was characterized in P. multocida 17BRD-035. It was also identified in three other isolates (two ST394s and a ST125) in Australia and is likely present in a genome representing P. multocida ST79 from the USA. ICE-PmuST394 houses a resistance module carrying two variants of the blaROB gene, blaROB-1 and blaROB-13, and the macrolide esterase gene, estT. The resistance gene combination on ICE-PmuST394 confers resistance to ampicillin and tilmicosin, but not to tulathromycin and tildipirosin. Our analysis suggests that ICE-PmuST394 is circulating both by clonal expansion and horizontal transfer but is currently restricted to a single feedlot in Australia. ICE-PmuST394 carries a limited number of unusual antimicrobial resistance genes but has hotspots that facilitate genomic recombination. The element is therefore amenable to hosting more resistance genes, and therefore its presence (or dispersal) should be regularly monitored. The element has a unique molecular marker, which could be exploited for genomic surveillance purposes locally and globally.

Prosocial Behaviour and Antibiotic Resistance: Evidence from a Discrete Choice Experiment.

The health of a community depends on the health of its individuals; therefore, individual health behaviour can implicitly affect the health of the entire community. This is particularly evident in the case of infectious diseases. Because the level of prosociality in a community might determine the effectiveness of health programmes, prosocial behaviour may be a crucial disease-control resource. This study aimed to extend the literature on prosociality and investigate the role of altruism in antibiotic decision making. A discrete choice experiment was conducted to assess the influence of altruism on the general public's preferences regarding antibiotic treatment options. The survey was completed by 378 Swedes. Latent class analysis models were used to estimate antibiotic treatment characteristics and preference heterogeneity. A three-class model resulted in the best model fit, and altruism significantly impacted preference heterogeneity. Our findings suggest that people with higher altruism levels had more pronounced preferences for treatment options with lower contributions to antibiotic resistance and a lower likelihood of treatment failure. Furthermore, altruism was statistically significantly associated with sex, education, and health literacy. Antibiotic awareness, trust in healthcare systems, and non-discriminatory priority setting appear to be structural elements conducive to judicious and prosocial antibiotic behaviour. This study suggests that prosocial messages could help to decrease the demand for antibiotic treatments.

Neisseria gonorrhoeae Antimicrobial Resistance: The Future of Antibiotic Therapy.

The growing threat of antibiotic-resistant Neisseria gonorrhoeae, which causes gonorrhea, presents a current public health challenge. Over the years, the pathogen has developed resistance to different antibiotics, leaving few effective treatment options. High-level resistance to key drugs, including ceftriaxone, has become a concerning reality. This article primarily focuses on the treatment of gonorrhea and the current clinical trials aimed at providing new antibiotic treatment options. We explore ongoing efforts to assess new antibiotics, including zoliflodacin, and gepotidacin. These drugs offer new effective treatment options, but their rapid availability remains uncertain. We delve into two ongoing clinical trials: one evaluating the efficacy and safety of gepotidacin compared to the standard ceftriaxone-azithromycin combination and the other assessing the non-inferiority of zoliflodacin versus the combination therapy of ceftriaxone-azithromycin. These trials represent crucial steps in the search for alternative treatments for uncomplicated gonorrhea. Notably, gonorrhea has been included in the "WHO Priority Pathogens List for Research and Development of New Antibiotics". In conclusion, the urgent need for innovative treatment strategies is underscored by the rising threat of antibiotic resistance in N. gonorrhoeae; collaboration among researchers, industries, and healthcare authorities is therefore essential.

2023 French recommendations for diagnosing and managing prepatellar and olecranon septic bursitis

Septic bursitis (SB) is a common condition accounting for one third of all cases of inflammatory bursitis. It is often related to professional activities. Management is heterogeneous and either ambulatory or hospital-based, with no recommendations available. This article presents recommendations for managing patients with septic bursitis gathered by 18 rheumatologists from the French Society for Rheumatology work group on bone and joint infections, 1 infectious diseases specialist, 2 orthopedic surgeons, 1 general practitioner and 1 emergency physician. This group used a literature review and expert opinions to establish 3 general principles and 11 recommendations for managing olecranon and prepatellar SB. The French Health authority (Haute Autorité de santé [HAS]) methodology was used for these recommendations. Designed for rheumatologists, general practitioners, emergency physicians and orthopedic surgeons, they focus on the use of biological tests and imaging in both outpatient and inpatient management. Antibiotic treatment options (drugs and duration) are proposed for both treatment modalities. Finally, surgical indications, non-drug treatments and prevention are covered by specific recommendations.

Prevalence of carbapenem-resistant and extended-spectrum beta-lactamase-producing Enterobacteriaceae in a teaching hospital in Ghana.

Carbapenem-resistant Enterobacteriaceae (CRE) and Extended-spectrum beta-lactamase (ESBL) production among Gram-negative Enterobacteriaceae is an increasing global challenge due to the high morbidity and mortality associated with their infections, especially in developing countries where there are little antibiotic treatment options. Despite these challenges, few studies in Ghana have described the burden of CRE. Therefore, this study aimed to determine the prevalence of carbapenem-resistant Enterobacteriaceae isolated from patients at the Cape Coast Teaching Hospital (CCTH) in the Central region of Ghana. Enterobacteriaceae isolates were collected from April to July 2019 at the bacteriology unit of CCTH using a consecutive sampling method. Isolates were identified by standard microbiological techniques and confirmed using API 20E. Kirby Bauer disc diffusion method was used to determine the antibiogram of isolates. Isolates were also subjected to ESBL testing using the single-disc combination method. Carbapenem-resistant isolates were identified by the Kirby Bauer disc diffusion method and then examined genotypically for the presence of blaKPC-1, blaIMP-1, blaVIM-1, blaNDM-1, and blaOXA-48 genes via polymerase chain reaction (PCR). Of the 230 isolates comprising E. coli (40.9%), Citrobacter spp. (32.6%), K. pneumoniae (9.1%), P. mirabilis (6.1%), P. vulgaris (5.2%), Enterobacter spp (3.5%)., K. oxytoca (2.2%), and Serratia marcenses (0.4%). Most isolates were from urine 162(70.4%) and wound samples. The isolates showed high resistance to ampicillin 171 (74.3%) and cefuroxime 134(58.3%). The prevalence of MDR was 35.2% (81), with E. coli 40(42.6%) being the majority that exhibited MDR. Of the 230 isolates, 113(49.1%) were ESBL producers, with E. coli 54(57.5%) accounting for the majority, while Serratia marcenses was the least. Of the 13 (5.7%) CRE isolates that showed resistance towards carbapenem in the disc diffusion method, 11 showed the presence of the blaNDM-1 gene, while all isolates showed the presence of the blaOXA-48 gene. The prevalence of carbapenem resistance and ESBL-producing Enterobacteriaceae pathogens among patients at the Cape Coast Teaching Hospital is high and alarming. Therefore, it is imperative to consider effective infection prevention and control measures should be implemented at the hospital to prevent the rapid spread of these dangerous organisms.

Application of Precision Medicine Concepts in Ambulatory Antibiotic Management of Acute Pyelonephritis.

Acute pyelonephritis (APN) is a relatively common community-acquired infection, particularly in women. The early appropriate antibiotic treatment of this potentially life-threatening infection is associated with improved outcomes. The international management guidelines for complicated urinary tract infections and APN recommend using oral antibiotics with <10% resistance among urinary pathogens. However, increasing antibiotic resistance rates among Escherichia coli and other Enterobacterales to fluoroquinolones, trimethoprim-sulfamethoxazole (TMP-SMX), and beta-lactams has left patients without reliable oral antibiotic treatment options for APN. This narrative review proposes using precision medicine concepts to improve empirical antibiotic therapy for APN in ambulatory settings. Whereas resistance rates to a particular antibiotic class may exceed 10% at the population-based level, the predicted antibiotic resistance rates based on patient-specific risk factors fall under 10% in many patients with APN on the individual level. The utilization of clinical tools for the prediction of fluoroquinolones, TMP-SMX, and third-generation cephalosporin resistance improves the ambulatory antibiotic management of APN. It may also reduce the need to switch antibiotic therapy later based on the in vitro antibiotic susceptibility testing results of bacterial isolates in urinary cultures. This approach may mitigate the burden of increasing antibiotic resistance in the community by ensuring that the initial antibiotic prescribed has the highest likelihood of treating APN appropriately.

Novel 3D versus traditional transesophageal echocardiography techniques: Defining differences in the diagnosis of infective endocarditis.

Despite the availability of current antibiotic and surgical treatment options, infective endocarditis (IE) remains associated with a high mortality rate. Even though two-dimensional (2D) transesophageal echocardiography (TOE) is a major criteria in the diagnosis of IE, it is constrained by the single-plane orientation. Since three-dimensional (3D) TOE provides a comprehensive understanding of the cardiac architecture by allowing for a realistic visualization of the underlying structures in 3D space, it has attracted considerable interest in recent years. The purpose of this narrative review is to discuss the advantages and pitfalls of 3D TOE in patients with IE, as well as to address emerging photo-realistic 3D techniques that have the potential to enhance the visualization of cardiac structures in this setting. According to recent research, 3D TOE acquisitions outperform 2D acquisitions in terms of vegetation identification accuracy and embolism risk assessment. By reporting a variety of findings that are missed with 2D TOE, but which are validated by surgical examination, 3D TOE further improves the ability to identify endocarditis complications on both native and prosthetic valves. In addition to conventional 3D TOE, future developments in 3D technology led to the development of transillumination and tissue-transparency rendering, which may improve anatomical understanding and depth perception. Due to the use of both conventional and novel 3D techniques, there are more patients who require surgical intervention, indicating that 3D TOE may have a clinical relevance on the surgical management. 3D TOE might fill the gaps left by 2D TOE in the diagnosis of IE.

Efficacy and Safety of Cefmetazole for Bacteremia Caused by Extended-Spectrum β-Lactamase-Producing Enterobacterales vs Carbapenems: A Retrospective Study.

Extended-spectrum β-lactamase (ESBL)-producing Enterobacterales have become a global concern owing to increased infections, high mortality, and limited antibiotic treatment options. Carbapenems (CPMs) are effective against ESBL-producing Enterobacterales, but their overuse leads to the emergence of multidrug-resistant bacteria. Cefmetazole (CMZ) is effective in vitro; however, its clinical efficacy remains unclear. We retrospectively reviewed patients who were treated with CMZ or CPMs for bacteremia caused by ESBL-producing Enterobacterales between 1 April 2014 and 31 September 2022 at Tenri Hospital. The primary outcome measure was 90-day mortality. We also evaluated resistance genes and sequence types of ESBL-producing Enterobacterales. In total, 156 patients were enrolled in this study. Ninety patients (58%) received CMZ therapy. Patients in the CMZ group were significantly older than those in the CPM group (median [IQR], 79 years [71-86] vs 74 years [64-83]; P = .001). The severity of the Pitt bacteremia score of the CMZ group was lower than that in the CPM group (0 [0-2] vs 2 [0-2], P = .042). Six patients (7%) in the CMZ group and 10 (15%) in the CPM group died by day 90 (P = .110). Charlson Comorbidity Index and prevalence of sequence 131 between the groups were statistically insignificant. Our findings suggest that CMZ is a well-tolerated alternative to CPM for treating bacteremia caused by ESBL-producing Enterobacterales.

Analyses of Extended-Spectrum-β-Lactamase, Metallo-β-Lactamase, and AmpC-β-Lactamase Producing Enterobacteriaceae from the Dairy Value Chain in India.

The consumption of milk contaminated with antibiotic-resistant bacteria poses a significant health threat to humans. This study aimed to investigate the prevalence of Enterobacteriaceae producing β-lactamases (ESBL, MBL, and AmpC) in cow and buffalo milk samples from two Indian states, Haryana and Assam. A total of 401 milk samples were collected from dairy farmers and vendors in the specified districts. Microbiological assays, antibiotic susceptibility testing, and PCR-based genotyping were employed to analyze 421 Gram-negative bacterial isolates. The overall prevalence of β-lactamase genes was 10% (confidence interval (CI) (7-13)), with higher rates in Haryana (13%, CI (9-19)) compared to Assam (7%, CI (4-11)). The identified β-lactamase genes in isolates were blaCMY, blaMOX, blaFOX, blaEBC, and blaDHA, associated with AmpC production. Additionally, blaCTX-M1, blaSHV, and blaTEM were detected as ESBL producers, while blaVIM, blaIMP, blaSPM, blaSIM, and blaGIM were identified as MBL producers. Notably, Shigella spp. were the dominant β-lactamase producers among identified Enterobacteriaceae. This study highlights the presence of various prevalent β-lactamase genes in milk isolates, indicating the potential risk of antimicrobial-resistant bacteria in dairy products. The presence of β-lactam resistance raises concern as this could restrict antibiotic options for treatment. The discordance between genotypic and phenotypic methods emphasizes the necessity for comprehensive approaches that integrate both techniques to accurately assess antibiotic resistance. Urgent collaborative action incorporating rational and regulated use of antibiotics across the dairy value chain is required to address the global challenge of β-lactam resistance.

Efficacy and safety of a 14-day modified concomitant therapy for refractory Helicobacter pylori infection: a pilot study.

After three treatment failures, Helicobacter pylori infection is deemed refractory as antibiotic treatment options become significantly limited. This study evaluated the efficacy and safety of a 14-day modified concomitant therapy for managing refractory H. pylori infection. Patients who had failed to respond to three or more rounds of H. pylori therapies were recruited for this study. They received a 14-day modified concomitant therapy, including esomeprazole 40mg, amoxicillin 1000mg, and furazolidone 100mg twice daily and tetracycline 500mg four times daily. Demographic data, adverse events, and patient compliance were recorded. The presence of H. pylori was reevaluated 6weeks following treatment. Eradication rate was assessed as the primary outcome. Overall, 59 participants received the 14-day modified concomitant therapy. In the intention-to-treat and per-protocol analyses, the eradication rate was 84.7% (50/59) and 89.3% (50/56), respectively. H. pylori was successfully isolated from 75.0% (12/16) of patients. The resistance rate of H. pylori to metronidazole, levofloxacin, and clarithromycin was 91.7% (11/12), 58.3% (7/12), and 50.0% (6/12), respectively. Resistance to amoxicillin, furazolidone, or tetracycline was not observed. The frequency of adverse events was 35.6% (21/59), with no serious adverse events reported. The 14-day modified concomitant therapy appears to be appropriate for refractory H. pylori infection and is particularly promising for the Chinese population. A randomized controlled trial is warranted to verify its efficacy, especially in the current environment of increasing antibiotic resistance.

Mobile colistin resistance (mcr) genes and recent developments in colistin resistance detection.

The peptide antibiotic colistin has been reserved as a last resort antibiotic treatment option for cases where other antibiotics including carbapenems have failed. Recent emergence of colistin resistance and discovery of mobile colistin resistance (mcr) genes, which encode the cell wall modifying phosphoethanolamine transferase enzyme, complicates the issue. The mcr genes have been associated with conjugative plasmids and can be horizontally transferred between different bacterial species. The global spread of mcr genes has been extensively documented and this warrants surveillance of the resistance genes in the community. However, susceptibility testing of colistin is fraught with practical challenges owing to the chemical nature of the drug and multiple mechanisms of resistance. Although broth microdilution is the current gold standard for colistin susceptibility testing, the method poses technical challenges. Hence alternative detection methods for screening colistin resistance are the need of the hour. Several methods have been studied in the recent times to address this issue. In this review, we discuss some of the recent developments in the detection of colistin resistance.

Antimicrobial activity of the Lacticaseibacillus rhamnosus CRL 2244 and its impact on the phenotypic and transcriptional responses in carbapenem resistant Acinetobacter baumannii

Carbapenem-resistant Acinetobacter baumannii (CRAB) is a recognized nosocomial pathogen with limited antibiotic treatment options. Lactic acid bacteria (LAB) constitute a promising therapeutic alternative. Here we studied the antibacterial properties of a collection of LAB strains using phenotypic and transcriptomic analysis against A. baumannii clinical strains. One strain, Lacticaseibacillus rhamnosus CRL 2244, demonstrated a potent inhibitory capacity on A. baumannii with a significant killing activity. Scanning electron microscopy images showed changes in the morphology of A. baumannii with an increased formation of outer membrane vesicles. Significant changes in the expression levels of a wide variety of genes were also observed. Interestingly, most of the modified genes were involved in a metabolic pathway known to be associated with the survival of A. baumannii. The paa operon, Hut system, and fatty acid degradation were some of the pathways that were induced. The analysis reveals the impact of Lcb. rhamnosus CRL 2244 on A. baumannii response, resulting in bacterial stress and subsequent cell death. These findings highlight the antibacterial properties of Lcb. rhamnosus CRL 2244 and its potential as an alternative or complementary strategy for treating infections. Further exploration and development of LAB as a treatment option could provide valuable alternatives for combating CRAB infections.

Whole genome analysis and antimicrobial resistance of Neisseria gonorrhoeae isolates from Ghana.

Gonorrhoea is a major public health concern. With the global emergence and spread of resistance to last-line antibiotic treatment options, gonorrhoea threatens to be untreatable in the future. Therefore, this study performed whole genome characterization of Neisseria gonorrhoeae collected in Ghana to identify lineages of circulating strains as well as their phenotypic and genotypic antimicrobial resistance (AMR) profiles. Whole genome sequencing (WGS) was performed on 56 isolates using both the Oxford Nanopore MinION and Illumina MiSeq sequencing platforms. The Comprehensive Antimicrobial Resistance Database (CARD) and PUBMLST.org/neisseria databases were used to catalogue chromosomal and plasmid genes implicated in AMR. The core genome multi-locus sequence typing (cgMLST) approach was used for comparative genomics analysis. In vitro resistance measured by the E-test method revealed 100%, 91.0% and 85.7% resistance to tetracycline, penicillin and ciprofloxacin, respectively. A total of 22 sequence types (STs) were identified by multilocus sequence typing (MLST), with ST-14422 (n = 10), ST-1927 (n = 8) and ST-11210 (n = 7) being the most prevalent. Six novel STs were also identified (ST-15634, 15636-15639 and 15641). All isolates harboured chromosomal AMR determinants that confer resistance to beta-lactam antimicrobials and tetracycline. A single cefixime-resistant strain, that belongs to N. gonorrhoeae multiantigen sequence type (NG-MAST) ST1407, a type associated with widespread cephalosporin resistance was identified. Neisseria gonorrhoeae Sequence Typing for Antimicrobial Resistance (NG-STAR), identified 29 unique sequence types, with ST-464 (n = 8) and the novel ST-3366 (n = 8) being the most prevalent. Notably, 20 of the 29 STs were novel, indicative of the unique nature of molecular AMR determinants in the Ghanaian strains. Plasmids were highly prevalent: pTetM and pblaTEM were found in 96% and 92% of isolates, respectively. The TEM-135 allele, which is an amino acid change away from producing a stable extended-spectrum β-lactamase that could result in complete cephalosporin resistance, was identified in 28.5% of the isolates. Using WGS, we characterized N. gonorrhoeae strains from Ghana, giving a snapshot of the current state of gonococcal AMR in the country and highlighting the need for constant genomic surveillance.