Combination Antibiotic Therapy Research Articles

The effect of combining antibiotics on resistance: A systematic review and meta-analysis.

When and under which conditions antibiotic combination therapy decelerates rather than accelerates resistance evolution is not well understood. We examined the effect of combining antibiotics on within-patient resistance development across various bacterial pathogens and antibiotics. We searched CENTRAL, EMBASE and PubMed for (quasi)-randomised controlled trials (RCTs) published from database inception to November 24th, 2022. Trials comparing antibiotic treatments with different numbers of antibiotics were included. A patient was considered to have acquired resistance if, at the follow-up culture, a resistant bacterium (as defined by the study authors) was detected that had not been present in the baseline culture. We combined results using a random effects model and performed meta-regression and stratified analyses. The trials' risk of bias was assessed with the Cochrane tool. 42 trials were eligible and 29, including 5054 patients, were qualified for statistical analysis. In most trials, resistance development was not the primary outcome and studies lacked power. The combined odds ratio (OR) for the acquisition of resistance comparing the group with the higher number of antibiotics with the comparison group was 1.23 (95% CI 0.68-2.25), with substantial between-study heterogeneity (I2 =77%). We identified tentative evidence for potential beneficial or detrimental effects of antibiotic combination therapy for specific pathogens or medical conditions. The evidence for combining a higher number of antibiotics compared to fewer from RCTs is scarce and overall, is compatible with both benefit or harm. Trials powered to detect differences in resistance development or well-designed observational studies are required to clarify the impact of combination therapy on resistance.

An Outbreak of Pan-drug Resistant Providencia Species in an Intensive Care Unit: A Case-Series

Background: Providencia species are opportunistic pathogens that can rarely cause nosocomial infections. They possess numerous virulence characteristics, such as intrinsic antibiotic resistance, which enable them to cause lethal outbreaks. The emergence of pan-drug resistant (PDR) isolates amplifies the threat of Providencia spp. to human health. Objectives: We described an outbreak caused by PDR Providencia spp. in the intensive care unit (ICU) of our medical center. Methods: This outbreak occurred at Imam Hossein Hospital in Tehran, Iran, between 20 June and 28 July 2023. The majority of the 14 patients experienced ventilator-associated pneumonia (VAP); however, two others had surgical site infections (SSI) and peritoneal abscesses. Samples were subcultured on Blood agar, Chocolate agar, and MacConkey agar, as well as differential gallery mediums. Additionally, susceptibility to antimicrobial agents was determined by the disk diffusion protocol using Mueller-Hinton (MH) agar. Results: The rapid diagnosis of the outbreak and practical measures recommended by the infection prevention and control (IPC) committee (e.g., sampling from other patients, hands of healthcare workers, and the environment to identify further cases and the source of the infection, contact isolation, disinfection of the ICU with 1% chlorine solution, and combined antibiotic therapy) assisted us in managing it. Nevertheless, the outbreak resulted in the mortality of eight patients, despite these preventive and therapeutic measures. Conclusions: Clinicians should be aware of nosocomial infections caused by opportunistic pathogens such as Providencia spp., especially in ICU-admitted patients with prolonged hospitalizations and broad-spectrum antibiotic administration. Strong clinical suspicion and timely detection of outbreaks, investigation of further cases, contact isolation of infected patients, disinfection of the environment, treatment with combined antibiotic regimens, and re-sampling of patients and the environment are the cornerstones of managing outbreaks caused by Providencia spp.

BRULURE CUTANEE CHEZ LES ENFANTS : ASPECTS CLINIQUES ET THERAPEUTIQUES DANS LE SERVICE DE CHIRURGIE GENERALE DE L’HOPITAL IGNACE DEEN CHU DE CONAKRY.

A burn is an injury to the skin covering and underlying structures caused by a thermal, electrical, radioactive or chemical agent. Objective: To study the clinical and therapeutic aspects of childhood skin burns in a Conakry university hospital. Methodology: This is a 4-year retrospective descriptive study from January 2018 to December 2021. We identified 55 burn patients. The average age was 3.16±2.85 years. The male gender was the most affected (n=33; 60%). Results: The burns were thermal in 80% of cases, hot liquid was the dominant causal agent with 85.45% of cases. We observed a dominance of second degree burns in 85% of cases. These burns were accidental in 100% of cases and occurred at home in 84% of cases. Treatment was medical and combined rehydration, antibiotic therapy and analgesia. Trimming and/or dressing was performed under general anesthesia for 26 patients (34.6%). A discharge aponeurotomy on the forearms wasperformed in 2 patients or 2.6% of cases. The evolution was favorable in 72.7% of cases. Seven children died Conclusion: Childhood burns occur at home and are mainly caused by thermal liquids. Clinically, it mainly causes second-degree lesions. Its treatment is medical and based on good rehydration associated with adequate antibiotic therapy and analgesia. Surgical care involves trimming and aponeurotomy. Keywords: burn, child, thermal agent, medical treatment

Molecular epidemiology and risk factors for carbapenem-resistant Enterobacteriaceae infections during 2020-2021 in Northwest China

Severe infection caused by Carbapenem-resistant Enterobacteriaceae (CRE) is a challenge for clinical anti-infective therapy, and clinical intervention to improve control of CRE is of great significance. The study aims to determine the molecular epidemiology and risk factors of CRE infections to provide evidence for effective control of nosocomial infection in patients with CRE. A total of 192 non-repetitive CRE strains were collected from January 2020 to December 2021 in Northwest China. To explore the risk factors of CRE infection by univariate and Logistic regression analysis, 1:1 case-control study was used to select Carbapenem sensitive Enterobacteriaceae (CSE) infection patients at the same period as the control group. Among the 192 CRE strains, the most common isolates included Klebsiella pneumoniae (Kpn) and Enterobacter cloacae (Ecl). The CRE strain showed the lowest rate of resistance to amikacin at 58.3. 185 CRE strains carried carbapenemase resistance genes of concern in this study. KPC-2 (n=94) was the most common carbapenemase, followed by NDM-1 (n=69), NDM-5 (n=22) and IMP-4 (n=5). OXA-48 and VIM were not detected. And KPC-2 was the most common in all strains. Logistic regression analysis implicated days of invasive ventilator-assisted ventilation (OR=1.452; 95 % CI 1.250～1.686), antibiotic combination therapy (OR=2.149; 95 % CI 1.128～4.094), hypoalbuminemia (OR=6.137; 95 % CI 3.161～11.913), history of immunosuppressant use (OR=25.815; 95 % CI 6.821～97.706) and days of hospitalization (OR=1.020; 95 % CI 1.006～1.035) as independent risk factors associated with CRE infection. Age (OR=0.963; 95% CI 0.943～0.984) and history of hormone use (OR=0.119; 95 % CI 0.028～0.504) were protective factors for CRE infection (P < 0.05). The resistance of commonly used antibiotics in clinical is severe, and CRE strains mainly carry KPC-2 and NDM-1. Multiple risk factors for CRE infection and their control can effectively prevent the spread of CRE.

Using host-mimicking conditions and a murine cutaneous abscess model to identify synergistic antibiotic combinations effective against Pseudomonas aeruginosa.

Antibiotic drug combination therapy is critical for the successful treatment of infections caused by multidrug resistant pathogens. We investigated the efficacy of β-lactam and β-lactam/β-lactamase inhibitor combinations with other antibiotics, against the hypervirulent, ceftazidime/avibactam resistant Pseudomonas aeruginosa Liverpool epidemic strain (LES) B58. Although minimum inhibitory concentrations in vitro differed by up to eighty-fold between standard and host-mimicking media, combinatorial effects only marginally changed between conditions for some combinations. Effective combinations in vitro were further tested in a chronic, high-density murine infection model. Colistin and azithromycin demonstrated combinatorial effects with ceftazidime and ceftazidime/avibactam both in vitro and in vivo. Conversely, while tobramycin and tigecycline exhibited strong synergy in vitro, this effect was not observed in vivo. Our approach of using host-mimicking conditions and a sophisticated animal model to evaluate drug synergy against bacterial pathogens represents a promising approach. This methodology may offer insights into the prediction of combination therapy outcomes and the identification of potential treatment failures.

Farnesol repurposing for prevention and treatment of Acinetobacter baumannii biofilms

Acinetobacter baumannii has emerged as a multidrug-resistant (MDR) superbug by causing severe infections, with high mortality rates. The ability of A. baumannii to form biofilms significantly contributes to its persistence in diverse environmental and hospital settings. Here we report that farnesol, an FDA-approved commercial cosmetic and flavoring agent, demonstrates efficacy for both inhibition of biofilm formation, and disruption of established A. baumannii biofilms. Moreover, no resistance to farnesol was observed even after prolonged culture in the presence of sub-inhibitory farnesol doses. Farnesol combats A. baumannii biofilms by direct killing, while also facilitating biofilm detachment. Furthermore, farnesol was safe, and effective, for both prevention and treatment of A. baumannii biofilms in an ex vivo burned human skin model. Since current treatment options for A. baumannii biofilm infections were mainly counted on the combination therapy of last-resort antibiotics, and clearly non-sustainable due to robust MDR phenotype of A. baumannii, we propose that farnesol alone can be repurposed as a highly effective agent for both preventing and treating life-threating biofilm-associated infections of A. baumannii due to its proven safety, convenient topical delivery, and excellent efficiency, plus its superiority of evading resistance development.

Novel synergistic interactions between monolaurin, a mono-acyl glycerol and β lactam antibiotics against Staphylococcus aureus: an in vitro study

BackgroundA major worldwide health issue is the rising frequency of resistance of bacteria.Drug combinations are a winning strategy in fighting resistant bacteria and might help in protecting the existing drugs.Monolaurin is natural compound extracted from coconut oil and has a promising antimicrobial activity against Staphylococcus.aureus. This study aims to examine the efficacy of monolaurin both individually and in combination with β-lactam antibiotics against Staphylococcus aureus isolates.MethodsAgar dilution method was used for determination of minimum inhibitory concentration (MIC) of monolaurin against S.aureus isolates. Scanning electron microscope (SEM) was used to detect morphological changes in S.aureus after treatment with monolaurin. Conventional and Real-time Polymerase chain reaction (RT-PCR) were performed to detect of beta-lactamase (blaZ) gene and its expressional levels after monolaurin treatment. Combination therapy of monolaurin and antibiotics was assessed through fractional inhibitory concentration and time-kill method.ResultsThe antibacterial activity of monolaurin was assessed on 115 S.aureus isolates, the MIC of monolaurin were 250 to 2000 µg/ml. SEM showed cell elongation and swelling in the outer membrane of S.aureus in the prescence of 1xMIC of monolaurin. blaZ gene was found in 73.9% of S.aureus isolates. RT-PCR shows a significant decrease in of blaZ gene expression at 250 and 500 µg/ml of monolaurin. Synergistic effects were detected through FIC method and time killing curve. Combination therapy established a significant reduction on the MIC value. The collective findings from the antibiotic combinations with monolaurin indicated synergism rates ranging from 83.3% to 100%.In time-kill studies, combination of monolaurin and β-lactam antibiotics produced a synergistic effect.ConclusionThis study showed that monolaurin may be a natural antibacterial agent against S. aureus, and may be an outstanding modulator of β-lactam drugs. The concurrent application of monolaurin and β-lactam antibiotics, exhibiting synergistic effects against S. aureus in vitro, holds promise as potential candidates for the development of combination therapies that target particularly, patients with bacterial infections that are nearly incurable.

Clinical outcomes in combination versus mono antibiotic therapy in ICU admitted patients with a suspected infection - A substudy of the DIANA study

PurposeIn a retrospective cohort study of intensive care unit (ICU) admitted adult patients with suspected or confirmed infection, associations between combination versus mono empirical antibiotic therapy and clinical cure at day 7 as well as mortality at day 7 and 28, were investigated. Materials and methodsPatients from the DIANA study were grouped and analysed by combination versus mono antibiotic therapy. Clinical cure was defined as survival and resolution of all signs and symptoms related to the infection. Odds ratios (ORs) were calculated by logistic regression analyses. ResultsOf the 1398 included patients, 568 patients (41%) received combination therapy. In total, 641(46%) patients achieved clinical cure and 135 (10%) patients had died as of day 7. There were no significant associations between combination and mono therapy relating to clinical cure and mortality. ConclusionsThis study found no differences in clinical cure and mortality between empirical combination versus mono therapy in a large cohort of ICU patients with a suspected infection.

Traitement des infections dues à des bacilles à Gram négatif en pédiatrie

Resistance of Gram-negative bacteria to the most widely used antibiotics, particularly β-lactams, is now considered as major public health problem. The main resistance mechanisms to β-lactams in Enterobacterales are the production of extended spectrum β-lactamases (ESBL) or carbapenemases, which hydrolyze virtually all β-lactams. However, a substantial proportion of carbapenem-resistant Gram-negative bacilli do not produce carbapenemase but combine overproduction of a cephalosporinase and/or ESBL with very low penem hydrolysis and reduced outer membrane permeability. The arrival of new antibacterial agents active on some of these multidrug-resistant strains, such as new β-lactam inhibitors, has marked a turning point in treatment and represents real progress. In-depth knowledge of resistance mechanisms is crucial to the choice of the most effective molecule, and their prescription requires close collaboration between microbiologists, infectious disease specialists and intensive care physicians. While these compounds are significantly more active against resistant strains than those previously available, their spectrum of activity does not cover all resistance mechanisms in Gram-negatives, nor in other bacterial species potentially involved in polymicrobial infections. The use of these new compounds does not alter antibiotic regimens in terms of duration and indication of combined antibiotic therapy, which remain very limited.

An Insight Into Various Manifestations of Leptospirosis: A Unique Case Series From a State in Eastern India.

Leptospirosis presents with highly variable clinical manifestations affecting different organ systems in different individuals. The presentation ranges from an asymptomatic or mild disease to a severe disease associated with multiorgan failure and higher mortality. Leptospirosis is highly underreported due to a lack of diagnostic modalities and less suspicion among clinicians. We present this single-center retrospective case series of 12 cases, which include various common and uncommon scenarios by which the disease can present and can be missed due to lack of suspicion. The study contains individual patient characteristics including demographic, laboratory, clinical, and treatment data. The association between these variables and mortality was analyzed using p-values and results were described. A p-value of<0.05 was considered statistically significant. A total of 12 cases were included in the study. The male-to-female ratio was 3:1. The mean age was higher (37.75±9.81 years) in cases who died than those who recovered (34.25±14.09). Factors like history of alcoholism, presence of chronic liver disease (CLD), jaundice, acute renal failure, requirement of dialysis, and requirement of intensive care were significantly associated with increased risk of death (odds ratio >1, p-value <0.05). The most common symptom of presentation was fever in 11 (91.66%) cases. Jaundice and renal failure were significantly associated with death (odds ratio 1.2, p-value 0.04). The requirement of intensive care treatment (odds ratio 2.1, p-value 0.05) and dialysis (odds ratio 39.66, p-value 0.03) were also significantly associated with death. The percentage of death was lower in the group of patients who received combination antibiotic therapy. Leptospirosis has varied presentations in different individuals and the diagnosis can be missed due to lack of specific signs and symptoms. Severe diseases involving multiple organs and preexisting comorbidities are associated with higher mortality rates. Timely diagnosis and treatment are necessary to reduce mortality and increase survival.

Periprosthetic Joint Infection as a Socio-Economic Problem of Modern Orthopedics

Periprosthetic joint infection is the main social and economic problem of modern orthopedics with a recurrence rate of chronic forms of up to 23.2–31.5%. The aim of this review is to inform various specialties doctors about the features of pathogenesis, etiology and treatment of periprosthetic joint infection, which significantly differ it from of other surgical site infections. The severity of infectious complications is due to the suppression of the patient’s immune system and microbial biofilms. Surgical treatment of periprosthetic joint infection involves debridement with preservation or removal of the implants, resection arthroplasty and arthrodesis. Today, in the treatment of more than 80% of cases of chronic infection, a two-stage approach is used, which allows to restore joint function after an average of 1.0–1.5 years. An integral part of the treatment of patients is high-dose, long-term and combined antibiotic therapy, which allows you to effectively deal with the leading pathogens of periprosthetic infection Staphylococcus aureus and S. epidermidis, the share of which is 46.5–57.5%. In the conditions of growing resistance of bacteria to antibiotics, the interest of researchers in the possibilities of using bacteriophages in the complex therapy of infections of bones and joints has increased. The cost of treatment exceeds the cost of “aseptic” joint replacement by 2–24 times and is characterized by a high level of disability and mortality of patients. Taking into account the numerous factors affecting the course and effectiveness of complex treatment of patients with periprosthetic infection, a multidisciplinary approach is currently considered the main component of success. The medical and social significance and high financial costs of treating patients with periprosthetic infection indicate the need for further research and the active implementation of effective scientific developments in the practical healthcare system.

Use of Aztreonam Plus Ceftazidime/Avibactam Combination for In vitro Susceptibility Testing of CRO Isolates in a Tertiary Care Hospital – Our experience

Abstract Background: Infections caused by metallo-beta-lactamases (MBLs) producing Gram-negative bacteria (mainly Enterobacterales) pose a great challenge for clinicians in treating these multidrug-resistant infections. In recent times, combination antibiotic therapy with ceftazidime–avibactam (CAZ-AVI) with aztreonam (ATM) has been researched by a number of laboratories worldwide and has gained much clinical attention. This study evaluated a practical laboratory method of testing for clinically significant in vitro synergy between CAZ/AVI + ATM in New Delhi MBLs (NDM) producing Gram-negative organisms. Materials and Methods: A total of 100 isolates of carbapenem-resistant Enterobacteriaceae (Klebsiella pneumoniae, Escherichia coli, Pseudomonas aeruginosa, and Enterobacter cloacae) were tested for synergy between CAZ/AVI + ATM using E-strip of CAZ/AVI and disc of ATM. The minimum inhibitory concentration value of CAZ/AVI was measured and the zone of inhibition was observed when ATM was placed parallel to the E-strip on a lawn culture of an isolate. Simultaneously, all isolates were tested for NDM and OXA-48 by Xpert Carba-R. Results: Of 100 isolates, 63/100 (63%) were harboring OXA-48 beta-lactamase, 54/100 (54%) were harboring NDM beta-lactamase and 18/100 (18%) were harboring both (OXA-48 and NDM). In vitro synergy between CAZ/AVI + ATM was noted in 99 isolates (99%). Conclusion: A significant synergy was demonstrated in vitro with CAZ/AVI + ATM combination therapy and seems to be a promising treatment strategy for infections caused by Enterobacterales harboring NDM and OXA-48 beta-lactamases.

The Impact of Mechanical Bowel Preparation and Oral Antibiotics in Colorectal Cancer Surgery (MECCA Study): A Prospective Randomized Clinical Trial.

Background: Colorectal cancer surgery has been associated with surgical site infections (SSIs), leading to an increase in postoperative morbidity, length of stay and total cost. The aim of the present randomized study was to investigate the relationship between the preoperative administration of oral antibiotic therapy and SSI rate, as well as other postoperative outcomes in patients undergoing colorectal cancer surgery. Material and Methods: Patients who underwent colorectal cancer surgery in a university surgical department were included in the present study. Patients were randomized into two groups using the "block randomization" method. The intervention group received three doses of 400 mg rifaximin and one dose of 500 mg metronidazole per os, as well as mechanical bowel preparation the day before surgery. The control group underwent only mechanical bowel preparation the day before surgery. The study has been registered in ClinicalTrials.gov (NCT03563586). Results: Two hundred and five patients were finally included in the present study, 97 of whom received preoperative antibiotic therapy per os (intervention group). Patients of this group demonstrated a significantly lower SSI rate compared with patients who did not receive preoperative antibiotic therapy (7% vs. 16%, p = 0.049). However, preoperative antibiotic administration was not correlated with any other postoperative outcome (anastomotic leak, overall complications, readmissions, length of stay). Conclusions: Preoperative antibiotic therapy in combination with mechanical bowel preparation seemed to be correlated with a lower SSI rate after colorectal cancer surgery.

Bacteriophage and antibiotic combination therapy for recurrent Enterococcus faecium bacteremia.

Phage therapy is an emerging therapeutic approach for treating bacterial infections that do not respond to traditional antibiotics. The addition of phage therapy to systemic antibiotics to treat a patient with recurrent E. faecium infections that were non-responsive to antibiotics alone resulted in fewer hospitalizations and improved the patient's quality of life. Combination phage and antibiotic therapy reduced E. faecium and VRE abundance in the patient's stool. Eventually, an anti-phage antibody response emerged that was able to neutralize phage activity, which may have limited clinical efficacy. This study demonstrates the potential of phages as an additional option in the antimicrobial toolbox for treating invasive enterococcal infections and highlights the need for further investigation to ensure phage therapy can be deployed for maximum clinical benefit.

DNases improve effectiveness of antibiotic treatment in murine polymicrobial sepsis.

Neutrophil extracellular traps (NETs) have various beneficial and detrimental effects in the body. It has been reported that some bacteria may evade the immune system when entangled in NETs. Thus, the aim of the current study was to evaluate the effects of a combined DNase and antibiotic therapy in a murine model of abdominal sepsis. C57BL/6 mice underwent a cecum-ligation-and-puncture procedure. We used wild-type and knockout mice with the same genetic background (PAD4-KO and DNase1-KO). Mice were treated with (I) antibiotics (Metronidazol/Cefuroxime), (II) DNAse1, or (III) with the combination of both; mock-treated mice served as controls. We employed a streak plate procedure and 16s-RNA analysis to evaluate bacterial translocation and quantified NETs formation by ELISA and immune fluorescence. Western blot and proteomics analysis were used to determine inflammation. A total of n=73 mice were used. Mice that were genetically unable to produce extended NETs or were treated with DNases displayed superior survival and bacterial clearance and reduced inflammation. DNase1 treatment significantly improved clearance of Gram-negative bacteria and survival rates. Importantly, the combination of DNase1 and antibiotics reduced tissue damage, neutrophil activation, and NETs formation in the affected intestinal tissue. The combination of antibiotics with DNase1 ameliorates abdominal sepsis. Gram-negative bacteria are cleared better when NETs are cleaved by DNase1. Future studies on antibiotic therapy should be combined with anti-NETs therapies.

Mortality and Risk Factors of Death in Patients with AmpC β-Lactamase Producing Enterobacterales Bloodstream Infection: A Cohort Study.

ESCPM bacteria include Enterobacter spp, Serratia, Citrobacter spp, Providencia spp, and Morganella spp. These Gram-negative bacilli harbor chromosomally encoded AmpC-type β-lactamases that cause resistance to β-lactam antibiotics, such as penicillins, β-lactam/β-lactamase inhibitors, and first-, second-, and third-generation cephalosporins. Bloodstream infections caused by ESCPM group bacteria (BSI-ESCPM) are difficult to treat. To describe 30-day mortality and analyze potential risk factors for death in patients with BSI-ESCPM. A cohort study of patients aged ≥ 18 years with BSI-ESCPM was conducted at a University Hospital in Brazil, from January 2013 and December 2018. Potential risk factors for death within 30 days of bloodstream infection BSI diagnosis were analyzed using multivariable logistic regression. Among 138 patients with BSI-ESCPM, 63.0% were males, with a median age of 61 years. Of 155 BSI-ESCPM episodes, 61.3% were hospital-acquired. Primary BSI-ESCPM associated with short-term central venous catheter (37.4%) and BSI-ESCPM secondary to respiratory infection (19.4%) occurred mainly. Mostly, Enterobacter spp. (49.7%) and Serratia spp. (29.0%) were isolated. Multidrug-resistance occurred in 27.7% of BSI-ESCPM episodes, involving Enterobacter spp. (16.1%) and Serratia spp. (7.7%) mainly. The mortality was 24.5%. Developing septic shock within 72 h of BSI-ESCPM diagnosis (OR: 70.26; 95% CI: 16.69-295.77; P<0.01) was risk factor for death. Conversely, combined antibiotic therapy (OR: 0.23; 95% CI: 0.05-0.94; P:0.04), BSI-ESCPM secondary to urinary infection (OR: 0.11; 95% CI: 0.01-0.99; P:0.05), and Enterobacter spp. BSI (OR: 0.16; 95% CI: 0.05-0.56; P0<0.01) was protective factor against death. Tendency of association between inadequate antibiotic therapy and death (OR: 2.19; 95% CI: 0.51-9.42; P:0.29) was observed. BSI-ESCPM is severe and has serious outcomes such as sepsis-associated deaths. Combined antibiotic therapy was a protective factor against death in patients with BSI-ESCPM. There is a suggestive association between inadequate antibiotic therapy and mortality. The ESCPM group bacteria that are considered to be at moderate to high risk of clinically significant AmpC production were not associated with death.

Insights and Opinions of Critical Care Healthcare Professionals in the Management of Carbapenem-resistant Enterobacteriaceae Cases and Antibiotic-Resistant Infections in the Intensive Care Unit Setting: A Survey-Based Approach.

A survey-based approach to managing antibiotic-resistant infections in the intensive care unit (ICU) setting, with a focus on carbapenem-resistant Enterobacteriaceae (CRE) cases, was conducted. Among CRE, New Delhi metallo-β-lactamase 1 (NDM-1) is a carbapenemase that is resistant to β-lactam antibiotics and has a broader spectrum of antimicrobial resistance than other carbapenemase types. The article explains that healthcare-associated infections (HAIs) are a significant problem, particularly in low- and middle-income countries, and that carbapenem in combination with other antibiotics are the most potent class of antimicrobial agents effective in treating life-threatening bacterial infections, including those caused by resistant strains. The survey aimed to gather critical care healthcare professionals (HCPs') opinions on their current practices in managing infections acquired in the hospital and ICU settings, with a focus on CRE cases, specifically NDM-1 and other antibiotic-resistant infections. Responses from critical care healthcare professionals, including online surveys and in-person interviews, to gain insights into the management of infections caused by multidrug-resistant bacteria. The findings related to the insights on the prevalence of bacterial flora, clinical experiences on efficacy and safety of meropenem sulbactam ethylenediaminetetraacetic acid (EDTA) (MSE) in CRE cases, and various combination therapies of antibiotics used to treat antibiotic-resistant infections in ICU setting were evaluated. Klebsiella pneumoniae bacteria were the most common bacteria in cultures, followed by Escherichia coli, Pseudomonas aeruginosa, and Acinetobacter baumannii. NDM-1 was the type of carbapenemase found in around 50% of CRE patients. MSE is among the most preferred antibiotics besides colistin, polymyxin B, and ceftazidime avibactum for CRE cases and specifically for NDM-1 cases due to its high rate of efficacy and safety. The article concludes with a discussion on the antibiotics used in response to CRE cases, reporting that critical care HCP considers MSE with high efficacy and safe antibiotic combination and was used as both monotherapy and in combination with other antibiotics. The survey highlights the need for exploring and better understanding the role of MSE in the management of CRE infections, especially in NDM-1.

INDIVIDUAL ARTICLE: Vehicles Matter!

Antibiotics, topical and oral, are a cornerstone in the treatment of acnes vulgaris specifically by targeting the skin bacterium Cutibacterium acnes. Billions of individuals have received antibiotics as part of their treatment resulting in a worldwide pandemic of antibiotic resistance not only for C. acnes but also many other pathogens. With the increasing prevalence of acne and exponentially increasing utilization of antibiotics, prescribers must urgently embrace the notion of antibiotic stewardship to maintain the efficacy of acne treatments while attenuating the rise of resistance. This paper serves as an update on C. acnes resistance to antibiotics commonly employed in the treatment of acne and the necessity of implementing benzoyl peroxide in the treatment&nbsp;regimen as monotherapy or combination antibiotic therapies for overcoming and preventing resistance. J Drugs Dermatol. 2024;23:1(Suppl 2):s4-10.

Machine Learning-Led Optimization of Combination Therapy: Confronting the Public Health Threat of Extensively Drug Resistant Gram-Negative Bacteria.

Developing optimized regimens for combination antibiotic therapy is challenging and often performed empirically over many clinical studies. Novel implementation of a hybrid machine-learning pharmacokinetic/pharmacodynamic/toxicodynamic (ML-PK/PD/TD) approach optimizes combination therapy using human PK/TD data along with in vitro PD data. This study utilized human population PK (PopPK) of aztreonam, ceftazidime/avibactam, and polymyxin B along with in vitro PDs from the Hollow Fiber Infection Model (HFIM) to derive optimal multi-drug regimens de novo through implementation of a genetic algorithm (GA). The mechanism-based PD model was constructed based on 7-day HFIM experiments across 4 clinical, extensively drug resistant Klebsiella pneumoniae isolates. GA-led optimization was performed using 13 different fitness functions to compare the effects of different efficacy (60%, 70%, 80%, or 90% of simulated subjects achieving bacterial counts of 102 CFU/mL) and toxicity (66% of simulated subjects having a target polymyxin B area under the concentration-time curve [AUC] of 100 mg·h/L and aztreonam AUC of 1,332 mg·h/L) on the optimized regimen. All regimens, except those most heavily weighted for toxicity prevention, were able to achieve the target efficacy threshold (102 CFU/mL). Overall, GA-based regimen optimization using preclinical data from animal-sparing in vitro studies and human PopPK produced clinically relevant dosage regimens similar to those developed empirically over many years for all three antibiotics. Taken together, these data provide significant insight into new therapeutic approaches incorporating ML to regimen design and treatment of resistant bacterial infections.

Pharmacokinetic/pharmacodynamic analysis of ceftazidime/avibactam and fosfomycin combinations in an in vitro hollow fiber infection model against multidrug-resistant Escherichia coli.

Mechanistic understanding of pharmacodynamic interactions is key for the development of rational antibiotic combination therapies to increase efficacy and suppress the development of resistances. Potent tools to provide those insights into pharmacodynamic drug interactions are semi-mechanistic modeling and simulation techniques. This study uses those techniques to provide a detailed understanding with regard to the direction and strength of the synergy of ceftazidime-avibactam and ceftazidime-fosfomycin in a clinical Escherichia coli isolate expressing extended spectrum beta-lactamase (CTX-M-15 and TEM-4) and carbapenemase (OXA-244) genes. Enhanced killing effects in combination were identified as a driver of the synergy and were translated from static time-kill experiments into the dynamic hollow fiber infection model. These findings in combination with a suppression of the emergence of resistance in combination emphasize a potential clinical benefit with regard to increased efficacy or to allow for dose reductions with maintained effect sizes to avoid toxicity.