Drug resistance of pathogens causing nosocomial infection in orthopedics from 2012 to 2017: a 6-year retrospective study

Eradication of Pseudomonas aeruginosa Persister Cells by Eravacycline

Pseudomonas aeruginosa is a leading bacterial pathogen that causes persistent infections. One major reason that antibiotics fail to clear such infections is the presence of a dormant subpopulation called persister cells. To eradicate persister cells, it is important to change drug development from traditional strategies that focus on growth inhibition to the search for new leads that can kill dormant cells. In this study, we demonstrate that eravacycline can effectively accumulate in P. aeruginosa persister cells, leading to strong killing during wakeup, including persister cells in both planktonic cultures and biofilms of the wild-type strain and its mucoid mutant. The effects of eravacycline on persister control were further validated in vivo using a lung infection model in mice. Collectively, these results demonstrate the possibility to control persister cells of bacterial pathogens by targeting dormancy.

[Nine-year trend in Escherichia coli resistance to ciprofloxacin: cross-sectional study in a hospital in Colombia]

Ciprofloxacin is a critically important antibiotic for human health. The increase of Escherichia coli resistance to ciprofloxacin is a global public health problem due to its importance in the treatment of complicated urinary tract infections and other serious infections; however, its prescription is high in the Colombian Caribbean. The objective was to determine the resistance trend of E. coli to ciprofloxacin in a Colombian hospital of high complexity. From antibiogram reports, isolates were categorized according to Clinical and Laboratory Standards Institute criteria for each year studied; proportions were calculated and differences in sensitivity were explored using the χ2 test. The Cochran-Armitage test was used to evaluate the resistance trend. Significance was considered when p-value ≤ 0.05. In total, 6,848 isolates were analyzed, and 49.31% resistance was found. According to origin, the highest resistance was in community samples (51.96% - 95%CI: 50.51; 53.41), and by type of sample, in skin and tissues (61.76% - 95%CI: 56.96; 66.35) and urine (48.97% - 95%CI: 47.71; 50.23). Increasing trends were observed for resistance per year (p < 0.0001), community samples (p = 0.0002) and urine (p < 0.0001). Resistance to ciprofloxacin is high and tends to increase in the community and in urine, exceeding the limit established for its use at the ambulatory level, which is of concern due to the high prescription of fluoroquinolones in the locality.

Molecular characterization of Staphylococcus aureus isolated from hospital-acquired infections in Ilam, Iran

OBJECTIVE

This research study was undertaken to investigate antimicrobial resistance patterns and the prevalence of hospital-acquired infections (HAIs). The study focuses on common microorganisms responsible for HAIs and explores emerging challenges posed by antimicrobial drug-resistant isolates.

METHODS

A comprehensive analysis of 123 patients with HAIs, hospitalized in surgical department and intensive care unit (ICU) at Imam Khomeini Hospital, Ilam, Iran, was conducted over a six-month period. Pathogenic bacterial isolates, including methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Staphylococcus aureus (VRSA), were isolated and subjected to antibiotic susceptibility testing.

RESULTS

The study findings revealed a significant prevalence of multidrug-resistant (MDR) isolates, of which 73.3% were MRSA. Notably, 6.7% of S. aureus isolates exhibited resistance to vancomycin, indicating the emergence of VRSA. Respiratory infections were identified as the most prevalent HAI, constituting 34.67% of cases, often arising from extended ICU stays and invasive surgical procedures. Furthermore, patients aged 60 and above, particularly those associated with MDR, exhibited higher vulnerability to HAI.

CONCLUSIONS

This research sheds light on the intricate interplay between drug resistance and HAI, highlighting the imperative role of rational antibiotic use and infection control in addressing this critical healthcare challenge.

Medical Device-Associated Biofilm Infections and Multidrug-Resistant Pathogens

Medical devices such as venous catheters (VCs) and urinary catheters (UCs) are widely used in the hospital setting. However, the implantation of these devices is often accompanied by complications. About 60 to 70% of nosocomial infections (NIs) are linked to biofilms. The main complication is the ability of microorganisms to adhere to surfaces and form biofilms which protect them and help them to persist in the host. Indeed, by crossing the skin barrier, the insertion of VC inevitably allows skin flora or accidental environmental contaminants to access the underlying tissues and cause fatal complications like bloodstream infections (BSIs). In fact, 80,000 central venous catheters-BSIs (CVC-BSIs)-mainly occur in intensive care units (ICUs) with a death rate of 12 to 25%. Similarly, catheter-associated urinary tract infections (CA-UTIs) are the most commonlyhospital-acquired infections (HAIs) worldwide.These infections represent up to 40% of NIs.In this review, we present a summary of biofilm formation steps. We provide an overview of two main and important infections in clinical settings linked to medical devices, namely the catheter-asociated bloodstream infections (CA-BSIs) and catheter-associated urinary tract infections (CA-UTIs), and highlight also the most multidrug resistant bacteria implicated in these infections. Furthermore, we draw attention toseveral useful prevention strategies, and advanced antimicrobial and antifouling approaches developed to reduce bacterial colonization on catheter surfaces and the incidence of the catheter-related infections.

Effectiveness of nursing intervention in the operating room to prevent pressure ulcer and wound infection in patients undergoing intertrochanteric fracture: A meta-analysis

In this study, a meta-analysis was conducted to comprehensively assess the effectiveness of nursing intervention in the operating room to prevent pressure ulcers and wound infections in patients with intertrochanteric fractures. A computerised search of PubMed, Cochrane Library, Embase, China National Knowledge Infrastructure (CNKI), VIP Database of Chinese Technical Periodicals, and Wanfang databases was performed to identify randomised controlled studies (RCTs) on the effectiveness of nursing intervention in the operating room for patients undergoing intertrochanteric fractures from the time of construction of the respective databases to June 2023. Two researchers independently searched and screened the literature, extracted information and performed quality assessments of the included literature. The meta-analysis was performed using RevMan 5.4 software. Eighteen studies were finally included, including 1517 patients, with 757 in the intervention group and 760 in the control group. The results showed that nursing intervention in the operating room significantly reduced the incidence of postoperative pressure ulcers in patients with intertrochanteric femoral fractures compared to the control group (1.69% vs. 6.01%, odds ratio [OR]: 0.32, 95% confidence interval [CI]: 0.18-0.57, p < 0.001) and reduced the incidence of surgical site wound infection (1.00% vs. 6.15%, OR: 0.23, 95% CI: 0.11-0.50, p < 0.001). Current evidence suggests that nursing intervention in the operating room is superior to routine care in reducing the incidence of pressure ulcers and wound infections in patients with intertrochanteric fractures and that such interventions should be promoted for clinical use.

Assessment of Prevalence and Diversity of Antimicrobial Resistant Escherichia coli from Retail Meats in Southern California

Retail meat products may serve as reservoirs and conduits for antimicrobial resistance, which is frequently monitored using Escherichia coli as indicator bacteria. In this study, E. coli isolation was conducted on 221 retail meat samples (56 chicken, 54 ground turkey, 55 ground beef, and 56 pork chops) collected over a one-year period from grocery stores in southern California. The overall prevalence of E. coli in retail meat samples was 47.51% (105/221), with E. coli contamination found to be significantly associated with meat type and season of sampling. From antimicrobial susceptibility testing, 51 isolates (48.57%) were susceptible to all antimicrobials tested, 54 (51.34%) were resistant to at least 1 drug, 39 (37.14%) to 2 or more drugs, and 21 (20.00%) to 3 or more drugs. Resistance to ampicillin, gentamicin, streptomycin, and tetracycline were significantly associated with meat type, with poultry counterparts (chicken or ground turkey) exhibiting higher odds for resistance to these drugs compared to non-poultry meats (beef and pork). From the 52 E. coli isolates selected to undergo whole-genome sequencing (WGS), 27 antimicrobial resistance genes (ARGs) were identified and predicted phenotypic AMR profiles with an overall sensitivity and specificity of 93.33% and 99.84%, respectively. Clustering assessment and co-occurrence networks revealed that the genomic AMR determinants of E. coli from retail meat were highly heterogeneous, with a sparsity of shared gene networks.

Evaluation of the Risk Factors of Nosocomial Pneumonia and the Prevalence of Antibiotic Resistance in Trauma Patients in Need of Immediate Intervention

Background: Pneumonia is the most common nosocomial infection reported worldwide in intensive care units. This study aimed to evaluate the risk factors of nosocomial pneumonia and the frequency of antibiotic resistance in trauma patients who need immediate intervention. Patients and Methods: This prospective cohort study was conducted in Shahid Rajaei Trauma Hospital in Shiraz between 2020 and 2021. All the trauma patients who needed immediate intervention (levels 1 and 2 based on the Canadian Emergency Department Triage and Acuity Scale) and had no symptoms of infection were included. Patients who were discharged or died before 48 hours were excluded. Results: The results demonstrated that major trauma (Injury Severity Score [ISS] ≥16), intubation, and use of invasive mechanical ventilation increase nosocomial pneumonia and death rate. The most common causes of nosocomial infections were Acinetobacter baumannii (23%) and coagulase-negative staphylococcus (18.5%). The highest levels of antibiotic resistance were related to cefoxitin, erythromycin, ciprofloxacin, and trimethoprim-sulfamethoxazole. Conclusions: Major trauma, intubation, and invasive mechanical ventilation were the effective factors in the development of nosocomial pneumonia. Continuous monitoring for mentioned risk factors and strict surveillance of antibiotic prescription can decrease the prevalence of nosocomial infections and subsequent deaths.

Pathogen Distribution, Drug Resistance Risk Factors, and Construction of Risk Prediction Model for Drug-Resistant Bacterial Infection in Hospitalized Patients at the Respiratory Department During the COVID-19 Pandemic

Objective

To investigate the distribution and drug resistance of pathogens among hospitalized patients in the respiratory unit during the COVID-19 pandemic, analyze the risk factors of drug resistance, construct a risk prediction model.

Methods

This study isolated 791 strains from 489 patients admitted to the Affiliated Hospital of Chengdu University, who were retrospectively enrolled between December 2019 and June 2021. The patients were divided into training and validation sets based on a random number table method (8:2). The baseline information, clinical characteristics, and culture results were collected using an electronic database and WHONET 5.6 software and compared between the two groups. A risk prediction model for drug-resistant bacteria was constructed using multi-factor logistic regression.

Results

K. pneumoniae (24.78%), P. aeruginosa (17.19%), A. baumannii (10.37%), and E. coli (10.37%) were the most abundant bacterial isolates. 174 isolates of drug-resistant bacteria were collected, ie, Carbapenem-resistant organism-strains, ESBL-producing strains, methicillin-resistant S. aureus, multi-drug resistance constituting 38.51%, 50.57%, 6.32%, 4.60%, respectively. The nosocomial infection prediction model of drug-resistant bacteria was developed based on the combined use of antimicrobials, pharmacological immunosuppression, PCT>0.5 ng/mL, CKD stage 4-5, indwelling catheter, and age > 60 years. The AUC under the ROC curve of the training and validation sets were 0.768 (95% CI: 0.624-0.817) and 0.753 (95% CI: 0.657-0.785), respectively. Our model revealed an acceptable prediction demonstrated by a non-significant Hosmer-Lemeshow test (training set, p=0.54; validation set, p=0.88).

Conclusion

K. pneumoniae, P. aeruginosa, A. baumannii, and E. coli were the most abundant bacterial isolates. Antimicrobial resistance among the common isolates was high for most routinely used antimicrobials and carbapenems. COVID-19 did not increase the drug resistance pressure of the main strains. The risk prediction model of drug-resistant bacterial infection is expected to improve the prevention and control of antibacterial-resistant bacterial infection in hospital settings.

Pharmaceutical Incompatibility of Lubricating Gel Formulation Reduces Antibacterial Activity of Chlorhexidine Gluconate: In Vitro Study in Northern Thailand

Chlorhexidine gluconate (CHG) is a cationic disinfectant. The positive charge of CHG molecules binds to phospholipid's negative charge in bacterial cell walls, causing membrane disruption. The in vitro kinetic physical, chemical and biological incompatibilities of nine lubricating gels with 1% w/v CHG were investigated. Five containing anionic thickener, two containing nonionic thickener, and two containing cationic thickener were collected from hospitals in northern Thailand. All the anionic and nonionic lubricating gels significantly reduced (p < 0.05) the CHG amount after 5 min of exposure time from 12.54% to 54.99%, respectively. In contrast, the amount of CHG exposed with cationic lubricating gels was maintained. Antibacterial activity was significantly reduced to a 1.17-4.33 log10 reduction for Staphylococcus aureus ATCC25923 and a 1.07-3.52 log10 reduction for Escherichia coli ATCC25922 after 5 min exposure to all anionic and nonionic lubricating gels. In contrast, the two cationic lubricating gels maintained the antibacterial activity of the CHG solution (5.69 ± 0.14 and 5.45 ± 0.17 log10 reduction). The results suggest that anionic and nonionic thickeners in lubricating gel formulations may neutralize the positive charge and reduce the antibacterial activity of CHG, reducing its effectiveness as a disinfectant.

ProbResist: a database for drug-resistant probiotic bacteria

Drug resistance remains a global threat, and the rising trend of consuming probiotic-containing foods, many of which harbor antibiotic resistant determinants, has raised serious health concerns. Currently, the lack of accessibility to location-, drug- and species-specific information of drug-resistant probiotics has hampered efforts to combat the global spread of drug resistance. Here, we describe the development of ProbResist, which is a manually curated online database that catalogs reports of probiotic bacteria that have been experimentally proven to be resistant to antibiotics. ProbResist allows users to search for information of drug resistance in probiotics by querying with the names of the bacteria, antibiotic or location. Retrieved results are presented in a downloadable table format containing the names of the antibiotic, probiotic species, resistant determinants, region where the study was conducted and digital article identifiers (PubMed Identifier and Digital Object Identifier) hyperlinked to the original sources. The webserver also presents a simple analysis of information stored in the database. Given the increasing reports of drug-resistant probiotics, an exclusive database is necessary to catalog them in one platform. It will enable medical practitioners and experts involved in policy making to access this information quickly and conveniently, thus contributing toward the broader goal of combating drug resistance.

Synthesis, Biological Activity and Molecular Docking Studies of Novel Nicotinic Acid Derivatives

In our research, we used nicotinic acid as a starting compound, which was subjected to a series of condensation reactions with appropriate aldehydes. As a result of these reactions, we were able to obtain a series of twelve acylhydrazones, two of which showed promising activity against Gram-positive bacteria (MIC = 1.95-15.62 µg/mL), especially against Staphylococcus epidermidis ATCC 12228 (MIC = 1.95 µg/mL). Moreover, the activity of compound 13 against the Staphylococcus aureus ATCC 43300 strain, i.e., the MRSA strain, was MIC = 7.81 µg/mL. Then, we subjected the entire series of acylhydrazones to a cyclization reaction in the acetic anhydride, thanks to which we were able to obtain twelve new 3-acetyl-2,5-disubstituted-1,3,4-oxadiazoline derivatives. Obtained 1,3,4-oxadiazolines were also tested for antimicrobial activity. The results showed high activity of compound 25 with a 5-nitrofuran substituent, which was active against all tested strains. The most promising activity of this compound was found against Gram-positive bacteria, in particular against Bacillus subtilis ATCC 6633 and Staphylococcus aureus ATCC 6538 (MIC = 7.81 µg/mL) and ATCC 43300 MRSA strains (MIC = 15.62 µg/mL). Importantly, the best performing compounds did not show cytotoxicity against normal cell lines. It seems practical to use some of these compounds or their derivatives in the future in the prevention and treatment of infections caused by some pathogenic or opportunistic microorganisms.

Non-Canonical Host Intracellular Niche Links to New Antimicrobial Resistance Mechanism

Globally, infectious diseases are one of the leading causes of death among people of all ages. The development of antimicrobials to treat infectious diseases has been one of the most significant advances in medical history. Alarmingly, antimicrobial resistance is a widespread phenomenon that will, without intervention, make currently treatable infections once again deadly. In an era of widespread antimicrobial resistance, there is a constant and pressing need to develop new antibacterial drugs. Unraveling the underlying resistance mechanisms is critical to fight this crisis. In this review, we summarize some emerging evidence of the non-canonical intracellular life cycle of two priority antimicrobial-resistant bacterial pathogens: Pseudomonas aeruginosa and Staphylococcus aureus. The bacterial factors that modulate this unique intracellular niche and its implications in contributing to resistance are discussed. We then briefly discuss some recent research that focused on the promises of boosting host immunity as a combination therapy with antimicrobials to eradicate these two particular pathogens. Finally, we summarize the importance of various strategies, including surveillance and vaccines, in mitigating the impacts of antimicrobial resistance in general.

A Meta-Analysis on Evaluation of Nosocomial Infections Amongst Patients in a Tertiary Care Hospital

Background

Hospital-acquired infections, also known as nosocomial infections, are one of the many severe outcomes amongst patients in tertiary care hospitals. Hospital-acquired influenza is amongst the most common infection which has affected huge population.

Objective

We have performed a meta-analysis in order to summarize the effects of epidemiology and clinical characteristics in HAI.

Methods

We performed literature review with help of PubMed, Cochrane Library, Embase, Scopus, Web of Science, China National Knowledge Infrastructure (CNKI), The Global Index Medicus (GIM), and other clinical databases till 2021. Many random models were used in order to obtain pooled proportions, mean difference, odds ratio, and CI.

Results

A total of six studies were analyzed, where a total of 491 nosocomial and 4030 nonnosocomial infection cases were reported. The odds ratio of mortality was 0.02 with 95% CI and the risk ration for males was 1.08 with 95% CI.

Conclusion

The proportion of nosocomial infections in cases of influenza was higher in patients admitted in tertiary care hospitals. Thus, a surveillance system for vaccination for all the high-risk patients must be made mandatory.

Molecular Characterization of KPC-2-Producing Enterobacter cloacae Complex Isolates from Cali, Colombia

The Enterobacter cloacae complex is an emerging opportunistic pathogen whose increased resistance to carbapenems is considered a public health problem. This is due to the loss of efficacy of beta-lactam antibiotics, which are used as the first treatment option in the management of infections caused by Gram-negative bacteria. The objective of this study was to perform the molecular characterization of 28 isolates of the E. cloacae complex resistant to cephalosporins and carbapenems isolated between 2011 and 2018 from five hospitals located in the municipality of Santiago de Cali, Colombia. Molecular detection of bla_KPC, bla_VIM, bla_NDM and bla_OXA-48-like genes was performed on these isolates and the genetic relationship between the isolates was assessed using multilocus sequence typing (MLST). Forty-three percent of the isolates carried the bla_KPC-2 gene variant. MLST showed high genetic diversity among isolates, the most frequent being the sequence type ST510 with a frequency of 50%. The identification of the genes involved in carbapenem resistance and dispersing genotypes is an important step toward the development of effective prevention and epidemiological surveillance strategies in Colombian hospitals.