ANTIBIOTIC SENSITIVITY OF BACTERIAL BLOODSTREAM INFECTIONS IN THE INTENSIVE CARE UNIT PATIENTS OF UNIVERSITY HOSPITALS IN SANA'A CITY, YEMEN
Eshtiaq A Al-Yosaffi1 , Hassan Abdulwahab Al-Shamahy1,2 , Arwa Mohammed Othman1 , Ahmed Mohammed Al-Haddad3 , Khaled Abdulkarim Al-Moyed1,4
1Medical Microbiology and Clinical Immunology Department, Faculty of Medicine and Health Sciences, Sana’a University.
2Medical Microbiology department, Faculty of Medicine, Genius University for Sciences & Technology, Dhamar city, Yemen.
3Department of Medical Laboratories, College of Medicine and Health Sciences, Hadhramout University, Al-Mukalla, Yemen.
4University of 21 September for Medical and applied Sciences, Sana’a, Yemen.
Aim: High rates of morbidity and mortality are associated to bacterial bloodstream infections (B-BSI) in many hospitals, especially in the intensive care unit. This study investigated the prevalence of antibiotic- and multidrug-resistant bacteria isolated from blood samples of patients in intensive care units of university hospitals in the city of Sana'a, Yemen.
Subjects and methods: A cross-sectional study was conducted on sepsis patients admitted to intensive care units in four hospitals in Sana'a, Yemen, between January 1 and April 30, 2022. The blood cultures of patients suspected of suffering from sepsis were performed. The potential bacterial pathogens were isolated and identified using standard laboratory methods, and microbial susceptibility testing was performed using the disk diffusion technique.
Results: For all identified bacteria, the average resistance rate to a broad spectrum of antibiotics tested ranged from 22.5% to 98.1%, with cefazoline (98.1%) having the greatest resistance rates, followed by amoxicillin (87.2%) and cefixime (83%). Vancomycin had a resistance rate of 4.8% whereas erythromycin had a resistance rate of 75% for Gram-positive bacteria. For Gram-negative bacteria, the resistance rates to narrow spectrum antibiotics ranged from 2.3% for colistin sulphate to 84.8% for aztreonam. Our isolates' MDR rates for resistance to at least three classes of antibiotics were 52.2% and 8.7%, respectively, for resistance to 10 different classes of broad-spectrum antibiotics and their subclasses.
Conclusion: Gram positive bacteria are highly resistant to erythromycin and penicillin, while gram negative organisms are highly resistant to amoxcillin+clavulanic acid, ciprofloxacin, and all generations of cephalosporins. This study highlights the significance of prompt clinical and bacteriological monitoring among patients in critical care conditions, such as ICU patients, and also illustrates the establishment and rates of Multi Drug Resistance (MDR) pathogens.
Keywords: Antibiotic resistant, bacteria, Bloodstream infections (BSIs), ICUs, multi-drug resistant.
INTRODUCTION
Bacterial sepsis is a life-threatening condition that arises when the body’s response to an infection injures its tissues and organs. A dysregulated host response to infection is now the new definition of sepsis, which is defined as life-threatening organ dysfunction. Since then, this disease entity has undergone numerous variations, with the late 19th century's advances laying the groundwork for our current understanding of sepsis. The general consensus that sepsis is a systemic infection caused by a harmful organism invading the host and spreading via the bloodstream (septicemia) was established as a result of the development of antiseptic measures, the germ theory of disease, and bacteriology. The pathogenesis of sepsis was not thought to be significantly more complex until the discovery of endotoxin and the continued widespread use of antibiotics1. One of the leading causes of illness and mortality worldwide continues to be bloodstream infection (BSI). Geographical variables can affect the variety of organisms that have been documented to cause BSI. Clinical staff members in charge of intensive care unit (ICU) patients face some of the most challenging issues when it comes to BSI2,3. Antimicrobial resistance is spreading globally for a variety of causes, the most significant of which is the rise in prescriptions, distribution in poorer nations, and indiscriminate use. A significant concern for global public health continues to be the estimated 700,000–multiple million deaths that take place each year4. Antimicrobial resistance-related mortality may become more common over time, according to predictions made by the World Health Organization (WHO) and United Nations study5-7. Antimicrobial resistance (AMR) is a significant public health risk in the modern era. Antimicrobial resistance bacteria are growing rapidly in a variety of hospital departments around the globe, but the issue is particularly severe and complicated in Yemen8-17. Regarding some specifics of the earlier research in Yemen, these studies mainly concentrated on examining the sensitivity to antibiotics for each bacterial isolate separately9-17, whereas the current study examined resistance to all bacterial isolates and also determined the temporal correlation of the rate of increase in the prevalence of bacterial isolate resistance to the studied antibiotics. Antimicrobial resistance is expected to become one of the major causes of death among hospitalized patients, especially immunocompromised patients such as ICU patients in developing countries including Yemen as well as even in developed countries, if appropriate control and prevention measures are not taken18-20. Antibiotics must be administered and used properly to treat bacterial infections21. Therefore, improper antibiotic prescribing and abuse may contribute to the development of pathogenic bacteria that are resistant to antibiotics, a limitation on available treatments, a lengthening of hospital stays, an increase in treatment expenses, and ultimately a rise in mortality22.
There is growing worry around the globe regarding the incidence of antibiotic resistance in blood-borne isolates23. BSI must therefore be regularly monitored. The inappropriate and illogical use of antibiotics has contributed to an increase in the development of antibiotic resistance (AMR) in Yemen, where the burden of infectious disease is among the highest in the world24. A high disease burden, inadequate infrastructure, deficient economic conditions, and uncontrolled over-the-counter sales of inexpensive antibiotics have all contributed to Yemen's AMR crisis 25,26. Being aware of the baseline microbial resistance unique to a hospital helps prevent the unnecessary use of antibiotics. This might be referred to as appropriate antibiotic stewardship27 and could help avoid the spread of antibiotic resistance.
The WHO Global Action Plan on antibiotic Resistance28 states that raising awareness of antibiotic resistance in research and monitoring initiatives around the globe is crucial. Monitoring bacterial resistance is important and has many advantages, such as: 1) giving information about the prevalence of bacterial resistance; 2) helping to choose the right antibiotics to lower the rate of bacterial resistance; 3) lowering treatment expenses and hospitalization rates; and 4) producing low death rates 22. Therefore, the goal of the current study is to ascertain the epidemiological profiles and antibiotic resistance of bacteria isolated from ICU sepsis patients admitted to 4 specialist hospitals in Sana'a city in 2022.
SUBJECTS AND METHODS
Study design and subjects: ICU patients admitted to Sana'a city's Al Kuwait, Al Gumhory, Al Sabeen, and Al-Thawra hospitals' ICUs between initial admission and first January 1 through April 30 in 2022 were the subjects of this cross-sectional study. Patients with suspected sepsis who were hospitalized for at least 72 hours during the study period were included.
Diagnosis of sepsis: Sepsis was suspected based on the presence of clinical indicators or risk factors and was confirmed as sepsis if a blood culture was positive, in accordance with international guidelines1. To record the clinical traits of sepsis patients, clinicians employed standardized tools. The guardians of all patients were informed of the study's goals before providing signed consent.
Ethical approval: All of the techniques employed in this study were authorized by the research and ethics committee of the Faculty of Medicine and Health Sciences at Sana'a University, Sana'a, Yemen (Approval No. UGR/SU-223).
Laboratory investigations:
Laboratory examinations were conducted in accordance with accepted microbiological practices29. Blood was added to a BacT/Alert PF plus culture bottle (BIOMERIEUX, France, LOT 4053532) with a minimum of 1 ml (typically 5 ml in adult patients), and the bottle was left to incubate until the BacT/Alert instrument (BACTEC 9050, Becton Dickinson) identified the culture as positive or negative. Then, after being sub-cultured on blood agar, MacConkey agar, and choclate agar, all positive samples were incubated at 37°C for 24-48 hours. Gram-staining was utilized to differentiate between gram-positive and gram-negative microorganisms. Enough pure culture colonies were used to suspend the bacteria in 3.0 ml of sterile saline in a test tube. Following the guidelines in the product information manuals (BIOMERIEUX), pure bacterial suspension was added to the bacterial specific identification and sensitivity testing kit device. The samples were then analyzed using the VITEK II system for bacterial bio-typing and antibiotic susceptibility. A VITEK ® GN ID identification card (lot 2410933203) was used to identify gram negative bacteria, and a VITEK ® GP ID identification card (lot 2420938203) was used to identify gram positive bacteria. Every treatment was administered for the usual therapeutic and diagnostic intents.
Antibiotic sensitivity test: Utilizing Kirby-Bauer disc diffusion techniques, antibiotic resistance was assessed, and CLSI was used to interpret antibiotic sensitivity data30. Typically, Sigma-Aldrich sources are used in NCPHL for antibiotic disks and medium powders. GPB and GNB isolates comprising Pseudomonas aeruginosa (ATCC 27853), Escherichia coli (ATCC 25922), and Staphylococcus aureus subsp. aureus ATCC 25923 were used as quality control for a routine DDM test recommended in the NCPHL Department of Microbiology. The antibiotic disks were utilized to evaluate the antibiotic susceptibility of GNB and Gram-positive bacteria. The study's conclusions were categorized as resistant (R), intermediate (I), or sensitive (S).
RESULTS
When it came to the poly-peptide classes of antibiotics, which were limited to testing for gram negative bacteria, the sensitivity rate for colistin sulphate was 90.9% (Table 4). We employed two varieties of each macrolide class azithromycin, which had a resistance rate of 77.8%, and erythromycin, which had a resistance rate of 75% for the classes of macrolides that were solely examined for isolated Gram-positive bacteria. Two types of aminoglycoside classes were also employed; they exhibited a 67.4% sensitivity rate to amikacin and a 41.8% resistance rate to gentamicin (none of which were tested against Streptococcus pyogenes) (Table 5). The susceptibility to the antibiotic families of oxazolidinones, lincosamides, and tetra-cyclines is shown in Table 6. The sensitivity rate of doxycycline is 75.3%, while the resistance rate is 32.5%. The categories of fluoroquinolone susceptibility and folate pathway inhibitors are shown in Table 7. For the fluoroquinolone classes, ciprofloxacin had a 66.3% resistance rate and levofloxacin a 32.6% sensitivity rate. For folate pathway inhibitors, the co-trimoxazole sensitivity rate was 55.8%
Figure 1 displays the range of antibiotic resistance rates for all identified bacteria, ranging from 22.5% to 98.1%, with cefazoline (98.1%) having the greatest resistance rates, followed by amoxicillin (87.2%) and cefixime (83%). For Gram-positive bacteria, the resistance rates to narrow spectrum antibiotics ranged from 4.8% for vancomycin to 75% for erythromycin. For Gram-negative bacteria, the resistance rates to narrow spectrum antibiotics ranged from 2.3% for colistin sulphate to 84.8% for aztreonam. Table 8 shows the prevalence of MDR among BSI isolates. The MDR that showed resistance to at least three classes of antibiotics for used isolates was 52.2%, and the MDR rate for resistance to 10 different classes of broad-spectrum antibiotics and their subclasses reached a rate equal to 8.7%.
Gram-negative bacteria were more common than Gram-positive bacteria overall, with frequencies of 50 (52.1%) and 42 (43.7%) respectively. E. coli had the highest frequency of identified Gram-negative bacteria at 20.8%, followed by Klebsiella spp. 11 (11.5%), Burkholderia cepacia 6, H. influenzae 5, Acintobacter baumannii 4, Pseudomonas aeruginosa 3, and Chryseobacterium indologenes 1. The highest frequency of isolated Gram-positive bacteria was coagulase negative Staphylococci 25 (26%) followed by S. aureus 9 (9.4%), S. pneumoniae 5 (5.2%), Enterococci 2 (2.1%) and S. pyogenes 1 (1.0%) respectively. For susceptibility to penicillin group antibiotics, the highest resistance rate was to piperacillin-tazobactam (76.1%) (Table 1). For the beta-lactam classes of cephalosporins, the highest susceptibility rate was to cefuroxime (47.1%), for the first generation the highest resistance rate was to cefazolin (98.1%), and for the third generation beta-lactam cephalosporins the highest resistance rate was to ceftriaxone (79.2%). (Table 2). Meropenem (63%) and imipenem (34.8%) had the highest sensitivity rates among the different carbapenem classes. In addition, monobactams were tested only on Gram-negative bacteria, and the resistance rate was 84.8%, while glycopeptides were only tested on Gram-positive bacteria, and the highest sensitivity rate was to vancomycin (95.2%) (Table 3).
DISCUSSION
The average proportion of resistance to broad-spectrum antibiotics evaluated for all identified bacteria in the current study ranged from 22.5% to 98.1%, with cefazoline having the greatest resistance rate at 98.1%, followed by amoxicillin at 87.2% and cefixime at 83%. This typically high incidence of resistance can be explained by the fact that antimicrobial usage in both humans and other animals, as well as the occurrence of resistant strains between the two, are primarily responsible for the rise in drug resistance31. The emission of inadequately treated effluents from the pharmaceutical industry, particularly in nations where bulk medicines are produced, has also been linked to an increase in resistance.
Antibiotics boost the rate at which the remaining resistant bacteria proliferate by increasing the selective pressure on bacterial populations, which causes the susceptible germs to perish. The advantage of resistant bacteria over weak microorganisms can exist even at relatively low levels of antibiotic use. Alternative therapies are becoming necessary as instances of antibiotic resistance increase. New antibiotic therapies have been demanded, but it is getting harder to produce new medications31,32. In tertiary hospitals in Sana'a, Yemen, the current study examined the prevalence of antibiotic resistance among the primary pathogenic bacteria isolated from ICU patients' blood.
One of the top concerns of clinicians worldwide is the occurrence and spread of these agents, which are certain to be capable of causing serious infections in ICU patients, particularly immunocompromised patients, the elderly, neonates, and children26,33,34. Because different patterns of antimicrobial resistance exist in different places, it is not permitted to administer multiple classes of antibiotics to neonates and children. It is also challenging to choose and prescribe the right antibiotics to treat various infections in immunocompromised, elderly, neonatal, and pediatric patients. Additionally, understanding the patterns of antibiotic resistance might assist physicians and policy officials in addressing the issues of resistance in their respective nations35.
Patients and healthcare professionals would use antibiotic resistance inappropriately as a result of the absence of public surveillance initiatives in developing nations like Yemen and many industrialized nations36-39. Investigation of antimicrobial resistance trends is therefore crucial and significant, particularly in underdeveloped nations like Yemen where there are no formal recommendations for the use of antibiotics. On the other hand, it is vital to look at the patterns of GPB and GNB antibiotic resistance in Sana'a city hospitals' intensive care units (ICUs) in 2022. This research could serve as a valuable model for policymakers and physicians implementing experimental treatments to ICU sepsis patients. The findings of the current study revealed that linezolid had a rate of resistance of 21.4% (Table 8), making it ineffective against Enterococcus spp. and S. aureus. This rate differed from those previously reported by Al-Shami et al.,25 (0.4%), Al-Huraibi et al.,40 (0.0%), and Al-Safani et al.,26 (<1%) in Yemen. The resistance to linezolid was also higher than that reported by Azimi et al., in Iran41, Dharmapalan et al., in India42, He et al., in China43, Li Tian et al., in China44, and Al-Naqshbandi and others in Iraq45, where it was less than 2%. However, the results of other investigations were consistent with the current study, and it has been reported that linezolid resistance is widespread and may reach 20% or more46,47.As of right now, 4.8% of Gram-positive bacteria were resistant to a restricted range of antibiotics, including vancomycin (Table 8). In contrast to the rates of vancomycin resistance reported by Al-Huraibi et al.,40 for S. aureus (0.0%) and total GPB by Al-Shami et al., 25, which was 7.8%, the resistance rate observed in the current study was greater at 18.0%. Many nations, including the USA, have implemented successful VRSA risk reduction strategies, and certain guidelines have been produced to prevent infections brought on by these pathogenic bacteria, according to a number of published research studies and reports48. As a result, we recommend comparable policies and initiatives created for patients in Sana'a, Yemen. The current study also demonstrated that, in contrast to ciprofloxacin (66.3% resistant rate), a restricted spectrum of antibiotics targeting Gram-negative bacteria, such as colistin, exhibited a 2.3% resistance rate (Table 8). These findings contrasted with those published by Azimi et al., who found that colistin has a higher rate of resistance than ciprofloxacin41, but were similar to those of Mahmoudi et al., from Iran22 and Dharmapalan et al., from India5
Sulfamethoxazole/trimethoprim, ceftazidime, ampic-illin, ceftorexime, cefazoline, cefadroxil, cefuroxime, cefixime, and cefotaxime are all ineffective antibiotics against GPB or GNB, according to the study's overall findings. It is important to note that these antibiotics are frequently used to treat various illnesses, particularly sepsis and septicemia, in Sana'a's hospitals. It is generally known that the misuse or overuse of antibiotics as well as bystander selection lead to the daily rise in antibiotic resistance, which is the cause of this49. So the following role must be followed in current situation: use antibiotics with caution if major pathogenic microorganisms have a resistance rate of > 40%. Drug sensitivity test findings must be utilized to choose which antibiotics to employ when major pathogenic bacteria have a resistance rate of > 50%. If the major pathogenic bacteria are more than 75% resistant to antibiotics, then antibiotic use must be discontinued. It is necessary to look into and assess feedback on bacterial resistance in order to decide if clinical usage of the medication can continue50. Given the high level of antibiotic resistance among bacteria, it is essential to accurately identify and use effective antibiotics for treatment in order to prevent the unintended consequences of sepsis and septicemia and to lower the mortality rate resulting from these infections51-54. Therefore, it is essential and strongly advised to be aware of the patterns of antibiotic resistance among common infections, to arrange workshops to rectify the prescribing of empirical therapy, and to make modifications in the usage of antibiotics.
The MDR rate in the current study was 52.2% (Table 8), which is higher than other reports that indicate MDR infections are common in patients admitted to the intensive care unit (ICU) and can have an incidence of up to 40%. These infections are typically linked to high mortality rates. Critically ill patients in intensive care units frequently have significant immune system failure as well as multiple organ dysfunctions. Patients' physiological barriers may be harmed by ventilators and invasive procedures, and ICU patients are more likely to become infected than patients in other departments55. ICU patients use antibiotics at a higher frequency, higher dose and longer duration, and infection with multiple drug-resistant bacteria (multidrug-resistant organisms; MDROs) is more severe compared with patients in other departments. Although bacteria have their own mechanisms for drug resistance, improper use of antibiotics, particularly abuse of third-generation cephalosporins, is the main cause of the high frequency of multidrug-resistant bacterial infection in ICUs56-59. According to studies, a significant cause of death for ICU patients is nosocomial infection. Improve the treatment effectiveness and prognosis of ICU patients by adopting clear, evidence-based prevention and control measures to drastically lower the incidence of nosocomial infection. To combat nosocomial infections and lower the risk of antibiotic resistance, lobbying efforts should be made.
Limitations of the study
The following were the study's limitations. First, we were unable to precisely identify the types of isolates and their patterns of antibiotic sensitivity in Yemen since the data only came from one place, Sana'a city. These isolates should be subjected to molecular studies in order to verify the presence of bacterial resistance genes.
CONCLUSION
The prevalence and antibiotic resistance of bacteria isolated from ICUs are briefly reviewed in this study's conclusion. In contrast to Erythromycin and Penicillin, which are extremely resistant to gram positive bacteria, E. coli was the most often isolated gram negative organism. It also exhibits strong resistance to amoxcillin+clavulanic acid, Ciprofloxacin, and all generations of cephalosporins. This study highlights the significance of timely clinical and bacteriological monitoring among patients in critical care conditions, such as ICU patients, and also demonstrates the appearance and rates of multi-drug resistant (MDR) pathogens. Antibiotics should also be administered with caution. ICUs and other critical care facilities should therefore establish antibiotic policies.
ACKNOWLEDGEMENTS
For their collaboration and support, we thank and appreciate all the medical staff at Kuwait, Al‑Jumhuri, Al-Sabeen, and Al-Thawra hospitals in Sana'a. We also acknowledge Sanaa University's assistance.
CONFLICT OF INTEREST
This work does not include any conflicts of interest.
AUTHOR’S CONTRIBUTIONS
Eshtiaq A. Al-Yousafi, the study's first author, conducted the fieldwork as part of her PhD studies at Sana'a University's Faculty of Medicine and Health Sciences' Department of Medical Microbiology. Additional authors contributed to the data analysis, the writing, reviewing, and final approval of the work.
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