Microbial Distribution and Antibiotic Susceptibility of Lower Respiratory Tract Infections Patients From Pediatric Ward, Adult Respiratory Ward, and Respiratory Intensive Care Unit

Disposable Peptidoglycan-Specific Biosensor for Noninvasive Real-Time Detection of Broad-Spectrum Gram-Positive Bacteria in Exhaled Breath Condensates

Rapidly identifying and quantifying Gram-positive bacteria are crucial to diagnosing and treating bacterial lower respiratory tract infections (LRTIs). This work presents a field-deployable biosensor for detecting Gram-positive bacteria from exhaled breath condensates (EBCs) based on peptidoglycan recognition using an aptamer. Dielectrophoretic force is employed to enrich the bacteria in 10 s without additional equipment or steps. Concurrently, the measurement of the sensor's interfacial capacitance is coupled to quantify the bacteria during the enrichment process. By incorporation of a semiconductor condenser, the whole detection process, including EBC collection, takes about 3 min. This biosensor has a detection limit of 10 CFU/mL, a linear range of up to 105 CFU/mL and a selectivity of 1479:1. It is cost-effective and disposable due to its low cost. The sensor provides a nonstaining, culture-free and PCR-independent solution for noninvasive and real-time diagnosis of Gram-positive bacterial LRTIs.

Antimicrobial Resistance Patterns of Common Gram-Negative Microorganisms Isolated from Patients with Lower Respiratory Tract Infections in a Teaching Hospital in Vietnam

This cross-sectional study investigated the antimicrobial resistance (AMR) patterns of gram-negative pathogens isolated from 4,789 hospitalized patients with lower respiratory tract infections (LRTIs). Of the collected specimens, 1,325 (27.7%) tested positive for gram-negative bacteria. Acinetobacter baumannii (38.6%), Pseudomonas aeruginosa (33.5%), Klebsiella pneumoniae (18.7%), Escherichia coli (5.6%), and Klebsiella aerogenes (3.5%) were the most prevalent isolates. AMR analysis revealed high resistance rates (79.9%-100%) of A. baumannii isolates to multiple classes of antibiotics except amikacin, trimethoprim/sulfamethoxazole, and colistin. P. aeruginosa displayed low resistance to colistin (< 10%) but high resistance to other antibiotics. K. pneumoniae displayed high resistance rates of 90.0%-100.0% to most penicillins, whereas resistance rates were notably lower for colistin (7.1%) and amikacin (16.7%). K. aerogenes exhibited high resistance to various antibiotics and sensitivity to amikacin (95.1%), ampicillin (100.0%), and colistin (100.0%). E. coli isolates exhibited resistance to ampicillin (96.9%) and maximum sensitivity to several antibiotics. Our study identified significant AMR trends and highlighted the prevalence of multidrug-resistant strains (93.6% for K. aerogenes and 69.1%-92.4% for other isolates). These findings emphasize the urgent need for appropriate antibiotic management practices to combat AMR in gram-negative pathogens associated with LRTIs.

Monitoring of antimicrobial resistance in respiratory tract pathogens during the COVID-19 pandemic: A retrospective study

To understand the distribution and antimicrobial resistance (AMR) of pathogens in respiratory samples in Changle District People's Hospital in Fujian Province in recent years, and provide empirical guidance for infection control and clinical treatment in the region. A retrospective analysis was conducted on 5137 isolates of pathogens from respiratory samples collected from 2019 to 2022. The AMR patterns were systematically analyzed. For research purposes, the data was accessed on October 12, 2023. A total of 3517 isolates were included in the study, including 811 (23.06%) gram-positive bacteria and 2706 (76.94%) gram-negative bacteria. The top 3 gram-positive bacteria were Staphylococcus aureus with 455 isolates (12.94%), Streptococcus pneumoniae with 99 isolates (2.81%), and Staphylococcus hemolytic with 99 isolates (2.81%). The top 3 gram-negative bacteria were Klebsiella pneumoniae with 815 isolates (23.17%), Pseudomonas aeruginosa with 589 isolates (16.75%), and Acinetobacter baumannii with 328 isolates (9.33%). The proportion of extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli and K pneumoniae fluctuated between 41.9% and 70.5%, and 18.6% and 20.9%, respectively. The resistance rates of E coli, K pneumoniae, P aeruginosa, and A baumannii to carbapenems were 2.36%, 8.9%, 18.5%, and 19.6%, respectively. The prevalence of methicillin-resistant S aureus (MRSA) was 48.55%, but it decreased to 38.4% by 2022. The resistance rate of Staphylococcus haemolyticus to methicillin was 100%, and 1 case of vancomycin-resistant strain was detected. K pneumoniae, P aeruginosa, A baumannii, and S aureus are the main pathogens in respiratory samples. Although the resistance rates of some multidrug-resistant strains have decreased, ESBL-producing Enterobacteriaceae, carbapenem-resistant bacteria have still increased. Therefore, it is necessary to strengthen the monitoring of pathogen resistance, promote rational use of antibiotics, and promptly report findings.

Increase in complicated upper respiratory tract infection in children during the 2022/2023 winter season-a post coronavirus disease 2019 effect?

BACKGROUND

Upper respiratory tract infections usually peak during winter months.

OBJECTIVE

The purpose of this study was to evaluate whether imaging of complicated upper airway infection in children increased during the winter season of 2022/2023.

MATERIALS AND METHODS

In a retrospective study setting, pediatric magnetic resonance imaging (MRI) and computed tomography (CT) scans for evaluation of upper respiratory tract infection performed between October 2022 and April 2023 were analyzed regarding presence of the following complications: mastoiditis, abscess, phlegmon, meningitis, reactive vasculitis, and sinus vein thrombosis. Pathogen detection, surgery, and infection parameters were obtained. Data were compared with MRI and CT scans performed in the same months of the preceding five years, distinguishing between pandemic and pre-pandemic years.

RESULTS

During the 2022/2023 winter season, the number of MRI and CT scans in children with upper airway infections, the complication rate, the rate of detected streptococcal infections, and the rate of surgery increased significantly compared to expectations based on the five prior winter seasons (all P<0.05). During the first complete pandemic winter season in Europe (2020/2021), the number of MRI and CT scans in children with upper airway infection, the complication rate, and the rates of streptococcal detection and surgery decreased significantly compared to expectations based on the pre-pandemic, the second pandemic, and the post-pandemic winter seasons (all P<0.05).

CONCLUSION

After a decline during the first pandemic winter season, there was a marked rebound in complicated upper airway infection in children, with a significant increase in cases during the 2022/2023 winter season compared to the pre-pandemic and pandemic years.

Impact of COVID-19 on the distribution of pathogenic bacteria in the lower respiratory tract of the elderly

BACKGROUND

To investigate the distribution of bacterial pathogens of lower respiratory tract infection (LRTI) in hospitalized elderly patients during the COVID-19 epidemic and to explore the influence of COVID-19 on the distribution of bacterial pathogens, to provide guidance for clinical diagnosis.

METHODS

Specimens of sputum from elderly LRTIs patients at Fuding Hospital of China were consecutively collected from October 2022 to January 2023. Cultures and identification were done, and RT-PCR was employed to detect SARS-Cov-2 nucleic acid.

RESULTS

A total of 195 isolates were characterized in 163 sputum samples of consecutive hospitalized elderly patients, of which 11.3% were Gram-positive bacteria and 88.7% were Gram-negative. The top of frequently isolated pathogens was Klebsiella pneumonia (30.3%), Pseudomonas aeruginosa (19.0%), Acinetobacter baumannii (12.8%), Stenotrophomonas maltophili, (7.7%), Escherichia coli (7.2%). According to the results of novel coronavirus nucleic acid detection, the 163 patients were divided into COVID-19 group and non-COVID control (CNT) group. The comparison of bacterial distribution between the groups revealed that Stenotrophomonas maltophilia was lower in the COVID-19 than in the CNT group, while A. baumannii was higher in the COVID-19 group, and the difference was statistically significant (p < .05).

CONCLUSION

The major bacteria identified in sputum culture of hospitalized elderly patients were K. pneumonia, P. aeruginosa, A. baumannii, S. maltophilia, and E. coli. Furthermore, the distribution of S. maltophilia and A. baumannii between the COVID-19 and CNT groups was found to be significantly different (p < .05), while there were no significant differences in the distribution of other bacteria.

Pathogenic bacteria recovered from Gene X-pert tuberculosis-negative adult patients in Gondar, Northwest Ethiopia

INTRODUCTION

Lower respiratory tract infections (LRTIs) caused by drug-resistant pathogenic bacteria is a major problem in developing countries including Ethiopia. Therefore, this study aimed to determine the pathogenic bacteria and their antimicrobial susceptibility patterns among Gene X-pert tuberculosis-negative adult patients with clinically suspected LRTIs at the University of Gondar Comprehensive Specialized Referral Hospital, Gondar, Northwest Ethiopia.

METHODS

This institutional-based cross-sectional study was conducted from February 01 to March 15, 2020. Socio-demographic data were collected by using a structured questionnaire. A total of 254 sputum specimens were collected from Gene X-pert tuberculosis-negative patients. Bacterial recovery was performed using blood, chocolate, and MacConkey agar plates. Bacterial isolates were identified based on Gram staining, colony characteristics, and biochemical reactions. Antimicrobial susceptibility testing was performed using the Kirby-Bauer disk diffusion method. Methicillin resistance of S. aureus was confirmed using cefoxitin (30 µg). Descriptive statistics were calculated for each variable and results are shown in tables and figures.

RESULTS

In this study, the overall sputum culture positivity rate was 145/254 (57.1%). Gram-negative bacteria 111 (64.9%) were predominant compared to Gram-positive bacteria 60 (35.1%). Of the 145 culture-positive cases, 26 (14.8%) had poly-bacterial infections. S. aureus 40 (66.7%) was the predominant Gram-positive bacterium whereas K. pneumoniae 33 (29.7%), was the most isolated Gram-negative bacterium. Bacterial species, such as S. aureus were sensitive to ciprofloxacin 38/40 (95.0%), gentamicin 37/40 (92.5%), cefoxitin 36/40 (90.0%), and clindamycin 34/40 (85.0%). The proportion of Methicillin-resistant S. aureus was low, 4(10.0%). S. pneumoniae was sensitive to chloramphenicol 8/9 (88.9%) and resistant to ciprofloxacin 6/9 (66.7%). K pneumoniae, P. aeruginosa, E. coli, Serratia species, and H. influenzae also demonstrated high levels of resistance to ampicillin at rates of 21/33 (63.6%), 8/8 (100.0%), 15/17 (88.2%), 7/10 (70.0%), and 6/6 (100.0%), respectively.

CONCLUSION

This study revealed a higher burden of Gram-negative and Gram-positive pathogenic bacterial agents, which is responsible for LRTs. Therefore, routine sputum culture identification and antibiotic susceptibility testing should be performed in Gene X-pert tuberculosis-negative patients.

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.

Analysis of the Distribution and Antibiotic Resistance of Pathogens Causing Infections in Hospitals from 2017 to 2019

Background. Antibiotic resistance is a global public health problem, leading to high mortality and treatment costs. To achieve more efficient treatment protocols and better patient recovery, the distribution and drug resistance of pathogens in our hospital were investigated, allowing significant clinical guidance for the use of antimicrobials. Methods. In this retrospective study (2017–2019), 3482 positive samples were isolated from 43,981 specimens in 2017; 3750 positive specimens were isolated from 42,923 specimens in 2018; and 3839 positive pathogens were isolated from 46,341 specimens in 2019. These samples were from various parts of the patients, including the respiratory tract, urine, blood, wound secretions, bile, and puncture fluids. The distribution and antibiotic resistance of these isolated pathogens from the whole hospital were analyzed. Results. The results from pathogen isolation showed that Escherichia coli (12.8%), Staphylococcus aureus (11%), Klebsiella pneumoniae (10.8%), Pseudomonas aeruginosa (10.7%), and Acinetobacter baumannii (6.4%) represented the five main pathogenic bacteria in our hospital. Pseudomonas aeruginosa (16.2% and 17.5%) occupied the largest proportion in the central intensive care unit (central ICU) and respiratory intensive care unit (RICU), while Acinetobacter baumannii (15.4%) was the most common pathogen in the emergency intensive care unit (EICU). The resistance rate of Escherichia coli to trimethoprim and minocycline was 100%, and the sensitivity rate to ertapenem, furantoin, and amikacin was above 90%. The resistance rate of Pseudomonas aeruginosa to all antibiotics, such as piperacillin and ciprofloxacin, was under 40%. The sensitivity rate of Acinetobacter baumannii to tigecycline and minocycline was less than 30%, and the resistance rate to many drugs such as piperacillin, ceftazidime, and imipenem was above 60%. Extended-spectrum β-lactamases (ESBLs)-producing Klebsiella pneumoniae (ESBLs-KPN) and carbapenem-resistant Klebsiella pneumoniae (CRE-KPN), ESBLs-producing Escherichia coli (ESBLs-ECO) and carbapenem-resistant Escherichia coli (CRE-ECO), multidrug-resistant Acinetobacter baumannii (MDR-AB), multidrug-resistant Pseudomonas aeruginosa (MDR-PAE), and methicillin-resistant Staphylococcus aureus (MRSA) are all important multidrug-resistant bacteria found in our hospital. The resistance rate of ESBLs-producing Enterobacteriaceae to ceftriaxone and amcarcillin-sulbactam was above 95%. CRE Enterobacteriaceae bacteria showed the highest resistance to amcarcillin-sulbactam (97.1%), and the resistance rates of MDR-AB to cefotaxime, cefepime, and aztreonam were 100%. The resistance rates of MDR-PAE to ceftazidime, imipenem, and levofloxacin were 100%, and the sensitivity rate to polymyxin B was above 98%. The resistance rate of MRSA to oxacillin was 100%, and the sensitivity rate to linezolid and vancomycin was 100%. Conclusion. The distribution of pathogenic bacteria in different hospital departments and sample sources was markedly different. Therefore, targeted prevention and control of key pathogenic bacteria in different hospital departments is necessary, and understanding both drug resistance and multiple drug resistance of the main pathogenic bacteria may provide guidance for the rational use of antibiotics in the clinic.

Positive Bacterial Culture among Lower Respiratory Tract Specimens of Patients in a Tertiary Care Centre: A Descriptive Cross-sectional Study

Introduction

Lower respiratory tract infection accounts for a great burden of disease worldwide. The problem has further increased due to increasing antimicrobial resistance. This study was done to find out prevalence of positive bacterial culture among lower respiratory tract specimens of patients in a tertiary care centre.

Methods

A descriptive cross-sectional study was done in the Laboratory of Clinical Microbiology in a tertiary care centre from May, 2021 to October, 2021. Ethical approval was received from the Institutional Review Committee (Reference number: 045-077/078). A total of 635 specimens were collected by convenience sampling. The specimens were cultured as per standard microbiological techniques. Antibiotic susceptibility was performed following Clinical and Laboratory Standards Institute (2020) guidelines. Microsoft Excel was used for data entry and analysis. Point estimate at 95% Confidence Interval was calculated along with frequency and proportion.

Results

Among the 635 lower respiratory specimens, 112 (17.63%) (111.97 to 112.03 at 95% Confidence Interval) showed positive bacterial culture. Klebsiella pneumoniae 44 (37.93%) was the commonest isolate followed by Acinetobacter calcoaceticus baumannii complex 34 (29.31%).

Conclusions

The prevalence of positive bacterial culture among lower respiratory specimens was lower when compared to other studies done in similar settings.

Keywords

antibiotic resistance; gram negative bacteria; respiratory tract infections.

Synergistic Effect of Polyphenol-Rich Complex of Plant and Green Propolis Extracts with Antibiotics against Respiratory Infections Causing Bacteria

Bacterial infections are a prevalent complication after primary viral respiratory infections and are associated with high morbidity and mortality. Antibiotics are widely used against bacterial respiratory pathogens; however, the rise in antibiotic-resistant strains urges us to search for new antimicrobial compounds, including ones that act synergistically with antibiotics. In this study, the minimal inhibitory (MIC) and minimal bactericidal (MBC) concentrations of a polyphenol-rich complex of green propolis, Tabebuia avellanedae bark, and Olea europaea leaf extracts against Staphylococcus aureus, Haemophilus influenzae, and Klebsiella pneumoniae were determined, followed by an analysis of the synergistic effect with clarithromycin, azithromycin, and amoxiclav (875/125 mg amoxicillin/clavulanic acid). A combination of extracts showed activity against all three bacterial strains, with MIC values ranging from 0.78 to 12.5 mg/mL and MBC values from 1.56 to 12.5 mg/mL. The extracts showed synergistic activity with azithromycin and clarithromycin against S. aureus, with clarithromycin against K. pneumoniae, and with all three tested antibiotics against H. influenzae. Synergy with clarithromycin was additionally evaluated in a time-kill assay where the synergistic effects against S. aureus and K. pneumoniae were seen within the first 6 h of incubation. The results show the potential of polyphenol-rich extracts in enhancing the efficacy of antibiotic therapy and indicate their potential to be used in the management of respiratory infections.

Microbial Distribution and Antibiotic Susceptibility of Bloodstream Infections in Different Intensive Care Units

Background: Bloodstream infection (BSI) is an increasing public health concern worldwide, representing a serious infection with significant morbidity and mortality, especially in children and the elderly. The predominant microbial distribution and antibiotic susceptibility were investigated among BSIs in the different intensive care units (ICUs)—pediatric ICU (PICU), surgical ICU (SICU), cardiac ICU (CICU), respiratory ICU (RICU), and geriatric ICU (GICU)—in order to achieve more efficient and appropriate therapies for patients in various ICUs.

Methods: In this retrospective cross-sectional study, the blood specimens were collected from five different ICUs of Peking University First Hospital and comprehensive ICU of Miyun Teaching Hospital (Miyun ICU) before antimicrobial treatment from 2017 to 2020. Microorganism cultures of the blood samples were conducted, and positive cultures were tested for type of pathogens and drug susceptibility.

Results: The prevalence of BSIs was the highest in the Miyun ICU (10.85%), followed by the RICU (9.48%) and the PICU (8.36%). The total prevalence of Gram-positive bacterial strains (especially Staphylococcus spp. and Enterococcus spp.) in the PICU (44.55%), SICU (57.58%), CICU (55.00%), GICU (49.06%), and Miyun ICU (57.58%) was higher than that of Gram-negative bacteria. The major bacterial strain was Acinetobacter baumannii in the PICU (21.82%); Klebsiella pneumoniae in the SICU (12.88%), CICU (30.00%), and RICU (30.39%); Escherichia coli in the GICU (20.75%); and Staphylococcus epidermidis (18.18%) in the Miyun ICU. Staphylococcus hominis of BSIs remained highly susceptible (>70%) to gentamicin, linezolid, daptomycin, teicoplanin, vancomycin, tigecycline, and rifampicin in all the ICUs. Its antibiotic sensitivity to levofloxacin was moderate in the PICU and CICU, but mild (<30%) in the SICU, RICU, and GICU. K. pneumoniae was highly susceptible to doxycycline, minocycline, and tigecycline in all the ICUs except the RICU, and its antibiotic sensitivity to imipenem, meropenem, amikacin, ciprofloxacin, and levofloxacin was high/moderate in the PICU, CICU, GICU, and Miyun ICU, but mild in the SICU and RICU.

Conclusion: The current study demonstrated the distribution of prevalent microorganisms, and their antimicrobial susceptibility exhibited a high divergence among BSIs in different ICUs from a tertiary hospital and an outer suburban hospital in Beijing. Therefore, different antibiotic therapies for various wards and distinct age groups (especially between pediatric and elderly patients) should be considered to control the emergence and spread of highly antibiotic-resistant infections.

Next-generation sequencing as an advanced supplementary tool for the diagnosis of pathogens in lower respiratory tract infections: An observational trial in Xi'an, China

The application of next-generation sequencing (NGS) in routine clinical analysis is still limited. The significance of NGS in the identification of pathogens of lower respiratory tract infection should be assessed as part of routine clinical bacterial examinations and chest imaging results. In the present study, the alveolar lavage fluid samples of 30 patients (25 males and 5 females, aged 19-92 years old, with a median age of 62) were examined by routine bacterial culture and NGS, and the results of pathogen detection and identification were compared. Chest imaging showed consolidation in all 30 patients (100%), and pleural effusion in 13 of the 30 patients (43.33%). The routine bacterial culture of the lavage solution was only positive in 14 of the 30 patients (46.6%), and negative in 16 patients (53.33%). However, the positive rate of NGS test results of the lavage fluid was 100%. A total of 12 cases (40%) were completely consistent with the routine bacterial culture test, with 56 other pathogens of mixed infection detected, accounting for the short comings of the routine bacterial examination. Although NGS cannot distinguish between live and dead bacteria, it is still a useful detection technology for accurate diagnosis of clinical infectious diseases. It is worthy of adaptation in the clinic for more effective clinical management and treatment of the lower respiratory airway infection in addition to the routine bacterial culture testing.

Lower Respiratory Tract Pathogens and Their Antimicrobial Susceptibility Pattern: A 5-Year Study

Lower respiratory tract infections (LRTIs) are the most common infections in humans. It is estimated that 2.74 million deaths worldwide occur each year due to LRTIs. The aim of the study was to determine the frequency and antibiotic susceptibility pattern of microorganisms isolated from respiratory samples of patients with LRTIs. Between January 2015 and December 2019, a total of 7038 sputum and bronchoaspirate samples from suspected LRTI patients were collected. Among them, 2753 samples (39.1%) showed significant microbial growth on culture media. The LRTI rate was higher in patients with male gender (67.1%) and with age between 40–59 years (48.6%). The microorganism identification and antibiotic susceptibility testing were performed with Vitek 2. Out of 4278 isolates species, 3102 (72.5%) were Gram-negative bacteria, 1048 (24.5%) were Gram-positive bacteria, and 128 (3.0%) were Candida spp. Major microorganisms isolated were Acinetobacter baumannii (18.6%), Staphylococcus aureus (15.2%), Pseudomonas aeruginosa (14.2%), and Klebsiella pneumoniae (10.9%). In antimicrobial susceptibility testing, Staphylococcus aureus isolates were mostly resistant to Penicillin G (84.1%) and Oxacillin (48.1%), whereas they demonstrated maximum sensitivity to Tigecycline (100%) and Linezolid (99.5%). Among Gram-negative isolates, Acinetobacter baumannii showed maximum sensitivity to Colistin but was resistant to other antibiotics (95–99%). Klebsiella pneumoniae isolates were mostly resistant to Cefotaxime (72.7%) and sensitive to Gentamicin (54.3%), and Pseudomonas aeruginosa was resistant to Ciprofloxacin (40.3%) and sensitive to Amikacin (85.9%). Gram-negative bacteria represented the species most commonly isolated. A high rate of antimicrobial resistance was observed in this study. In conclusion, the correct identification of causative microorganisms and their susceptibility patterns to antibiotics is crucial for choosing targeted and effective antibiotic therapy in LRTIs, and to prevent the emergence of multidrug-resistant bacteria.

Multimodal Interventions to Prevent and Control Carbapenem-Resistant Enterobacteriaceae and Extended-Spectrum β-Lactamase Producer-Associated Infections at a Tertiary Care Hospital in Egypt

The current rise of multidrug-resistant (MDR) Gram-negative Enterobacteriaceae including the extended-spectrum β-lactamase (ESBL)-producing organisms and carbapenem-resistant Enterobacteriaceae (CRE) has been increasingly reported worldwide, posing new challenges to health care facilities. Accordingly, we evaluated the impact of multimodal infection control interventions at one of the major tertiary healthcare settings in Egypt for the aim of combating infections by the respective pathogens. During the 6-month pre-intervention period, the incidence rate of CRE and ESBL-producing clinical cultures were 1.3 and 0.8/1000 patient days, respectively. During the post-intervention period, the incidence of CRE and ESBL producers continued to decrease, reaching 0.5 and 0.28/1000 patient days, respectively. The susceptibility rate to carbapenems among ESBL producers ranged from 91.4% (ertapenem) to 98.3% (imipenem), amikacin (93%), gentamicin (56.9%), and tobramycin (46.6%). CRE showed the highest resistance pattern toward all of the tested β-lactams and aminoglycosides, ranging from 87.3% to 94.5%. Both CRE and ESBL producers showed a high susceptibility rate (greater than 85.5%) to colistin and tigecycline. In conclusion, our findings revealed the effectiveness of implementing multidisciplinary approaches in controlling and treating infections elicited by CRE and ESBL producers.

Correlation between the Antibiotic Resistance Genes and Susceptibility to Antibiotics among the Carbapenem-Resistant Gram-Negative Pathogens

In this study, the correlation between the antibiotic resistance genes and antibiotic susceptibility among the carbapenem-resistant Gram-negative pathogens (CRGNPs) recovered from patients diagnosed with acute pneumonia in Egypt was found. A total of 194 isolates including Klebsiella pneumoniae (89; 46%), Escherichia coli (47; 24%) and Pseudomonas aeruginosa (58; 30%) were recovered. Of these, 34 (18%) isolates were multiple drug resistant (MDR) and carbapenem resistant. For the K. pneumoniae MDR isolates (n = 22), bla_NDM (14; 64%) was the most prevalent carbapenemase, followed by bla_OXA-48 (11; 50%) and bla_VIM (4; 18%). A significant association (p value < 0.05) was observed between the multidrug efflux pump (AcrA) and resistance to β-lactams and the aminoglycoside acetyl transferase gene (aac-6’-Ib) gene and resistance to ciprofloxacin, azithromycin and β-lactams (except for aztreonam). For P. aeruginosa, a significant association was noticed between the presence of the bla_SHV gene and the multidrug efflux pump (MexA) and resistance to fluoroquinolones, amikacin, tobramycin, co-trimoxazole and β-lactams and between the aac-6’-Ib gene and resistance to aminoglycosides. All P. aeruginosa isolates (100%) harbored the MexAB-OprM multidrug efflux pump while 86% of the K. pneumoniae isolates harbored the AcrAB-TolC pump. Our results are of great medical importance for the guidance of healthcare practitioners for effective antibiotic prescription.