Iranian Journal of Medical Microbiology

This study was done using a cross-sectional method conducted at Dr. M. Djamil General Hospital starting in August 2022. The population of this study was all patients with a diagnosis of sepsis who were admitted to the ward of the Department of Internal Medicine and other wards treated together with the Division of Tropical and Infectious Diseases of Dr. M. Djamil General Hospital. The samples of this study were subjects from the study population who met the inclusion criteria (age > 18 years, agreed as research subject) and did not have exclusion criteria (refused to be the subject of the study, patients with no microorganisms growth in the culture results).
We collected data such as age, gender, comorbidity, and severity of illness assessed based on SOFA score, nutritional factors as seen from Body Mass Index (BMI), history of antibiotic use, and medical device use. Then a bacterial culture test is performed with blood culture in addition to the other cultures (sputum, urine, feces, or pus) depending on the focus of infection. All culture specimens were sent to the Microbiology Laboratory of Dr. M. Djamil General Hospital.
The analysis of this study included descriptive, bivariate, and multivariate analysis. Descriptive analysis was performed to see the frequency distribution of each variable. Numerical data were presented in the form of numbers and percentages. Bivariate analysis determined the relationship between each variable and the number of MDROs in sepsis patients. Bivariate analysis was performed using the chi-square test. If P-value< 0.05, it was considered significant. If the P-value was < 0.25, then the variable would be included in the multivariate analysis. Multivariate analysis began with a logistic regression test to identify indicators that were risk factors for mortality. If it is known that the P-value< 0.05 and the prevalence odd ratio (POR) with the most value > 1, it is considered the most dominant factor.
 
 

In this study, we analyzed the factors associated with the incidence of MDROs in sepsis patients admitted to Dr. M. Djamil General Hospital, including gender, age, comorbidity, SOFA score, infectious disease, history of antibiotic use, nutritional status (BMI), medical device use, type of bacteria causing sepsis, antibiotic escalation, and initial empirical antibiotic administration in 101 patients consisting of 124 isolates with 83 MDROs isolates.
There were 101 patients with 124 isolates that met the inclusion and exclusion criteria of the study, consisting of 64 patients with 83 (66.93%) MDRO isolates and 37 patients with 41 (33.06%) non-MDRO isolates. Among the 83 MDRO isolates, we found 54 (65.06%) ESBL isolates, 15 (18.07%) CRO isolates, 13 (15.66%) MRSA isolates, and 2 (2.40%) VRE isolates. Characteristics of the study subjects are shown in Table 1.

Table 1. Characteristics of the study subjects

Most subjects were males with MDRO criteria (57.8%) compared to non-MDRO criteria (51.2%). There were also more MDRO criteria found in women (42.2%). The results of this study are in line with research conducted at the Arifin Achmad Regional General Hospital, Riau Province, in 2017, which shows the characteristics of research subjects with sepsis tend to be more common in males (51.85%). Theoretically, this is due to the effect of the 5a-dihydrotestosterone (DHT) hormone, which can suppress the number of anti-inflammatory cytokines that impact the growth of bacteria. Whereas in women, the estrogen hormone has an immunoprotective effect on immune function (13).
Another factor is age, which in this study was more prevalent in subjects aged 18-65 years with MDRO criteria (62.7%). This study categorized age into two groups, 18-65 years old and > 65 years old, because, at an older age, the immune system has decreased; thus, they are more susceptible to sepsis. This is consistent with research conducted at the Arifin Achmad Regional General Hospital in Riau Province in 2017 on sepsis patients in the age group of 17-65 years (74.04%) (13).

Table 2. The Comorbidities of The Study Subjects

Comorbid diseases are also one of the factors reviewed in this study as a risk factor for MDROs. In 64 sepsis patients with MDROs isolated, several patients had more than 1 comorbid disease (Table 2). There were 89 comorbid diseases in this study, with the highest number of comorbidities being chronic kidney disease, type 2 diabetes mellitus, and malignancy. A study at Dr. Moewardi Surakarta Regional General Hospital in 2021 which observed the correlation between antibiotic resistance and the incidence of sepsis and hospital mortality in the population with bacterial pneumonia infection, showed that the participants had several comorbid diseases in patients with MDROSs with the majority were cerebrovascular disease (15.8%), uncomplicated diabetes mellitus (13.2%), and chronic kidney disease (10.5%) (14). Zilberberg et al. in 2014 showed different results; out of 311 sepsis patients who died, 41.16% had malignancy as a comorbid disease, 29.58% had COPD, and 25.40% had diabetes (15).
Body Mass Index (BMI) in assessing the nutritional status of sepsis patients in this study was 53.0% in normal BMI status with the MDROs category, 28.9% were underweight, and 18.1% were overweight-obese with the MDROs category. This result shows that most of the subjects have a normal BMI (53.0%). This is similar to a study in the Department of Microbiology, Magdeburg, Germany, in 2021, which showed that most sepsis patients had a normal BMI (64.1%) (16).
The antibiotic use as initial therapy for sepsis patients with MDROs used a combination of therapeutic regimens such as Cefepime + Levofloxacin (44.6%), Ceftriaxone + Levofloxacin (8.4%), and Meropenem + Levofloxacin (4.8%), in addition, single empirical therapy was also given to the subjects such as the use of Ceftriaxone (7.2%) and Ciprofloxacin (4.8%). A review article by Martinez et al. in 2019 explained that the use of combination therapy using two different classes of antibiotics is useful for accelerating pathogen clearance and ensuring pathogen susceptibility to treatment. However, monotherapy is usually used to reduce antibiotic pressure, i.e., the incidence of superinfections or the emergence of new infections. Studies on the efficacy of combination therapy have shown mixed results, with some observational studies showing the superiority of combination therapy over monotherapy in patients with sepsis and septic shock (17).
In this study, the most common infectious disease causing sepsis was Hospital Acquired Pneumonia (54.2%) followed by Community Acquired Pneumonia (25.3%). Hospital-acquired Acquired Pneumonia is diagnosed when pneumonia occurs after the patient has been hospitalized for more than 48 hours, while Community-Acquired Pneumonia is diagnosed when pneumonia is acquired without a previous history of hospitalization.
In sepsis patients with MDRO infection, empirical antibiotics with a broad spectrum are needed. In this study, sepsis patients with MDROs received antibiotic escalation by 32.5%. This may be due to the initial empirical antibiotic selection in this study that was well enough, thus we did not perform antibiotic escalation in patient care.
In this study, at least 73.5% of subjects with MDROs had a history of antibiotic use. This is consistent with Nicolo et al. 's study in Milan, Italy, from 2011 to 2015, which showed that 76.6% of sepsis patients had at least one risk factor for MDROs, one of which was a history of antibiotic therapy in the last 90 days (11).
Various bacteria caused MDROs in our subjects; the most common bacteria found were K. pneumonia (27.7%), Escherichia coli (26.5%), Staphylococcus aureus (15.7%), followed by A. baumannii (13.3%). In line with a study in the GICU of DR. Mohammad Hoesin Palembang Central General Hospital in 2018, the results of bacterial culture showed that the three most common types of bacteria were A. baumannii (33%), Pseudomonas aeruginosa (24%), and K. pneumoniae (11%) (18).
In this study, the most common type of MDROs was ESBL (43.5%), followed by CRO (12.1%), with the most types of specimens found to be sputum specimens, with 63 specimens out of a total of 83 MDROs specimens (Table 3).

Table 3. MDROs type based on culture specimen

Abbreviation: MDROs = multidrug-resistant microorganisms, ESBL = extended-spectrum beta-lactamase producing enterobacteria, CRO = carbapenem resistance organisms, MRSA = methicillin-resistant staphylococcus aureus, VRE = vancomycin resistance enterococcus

In this study, it was found that the most types of MDROs were ESBL types (43.5%), followed by CRO (12.1%), with the majority of specimens coming from sputum specimens in a total of 63 sputum specimens, 26 blood specimens, 20 urine specimens, 12 pus specimens, and 3 feces specimens. A total of 124 isolates were obtained from 101 patients. Out of 101 patients, 64 patients resulted in 83 MDROs isolates. A study in Nanjing Hospital, China, 2020 on MDRO patients found that CRAB was the most common type of MDRO (820), followed by CRE (710), MRSA (413), and CRPA (371). Meanwhile, the specimens with the most MDROs were BALF (9.75%) and sputum (3.07%). Generally, specimens used to examine lower respiratory tract infections are sputum and BALF. Still, sputum tends to be easily contaminated by oral colonizing bacteria compared to BALF specimens which are alveolar surface fluid collected by bronchoscopy with less possibility of contamination and has sensitivity and specificity in the diagnosis of lower respiratory tract infections (19).
Table 4 showed that there was a statistically significant correlation (p = 0.024) between the history of antibiotic use and the incidence of MDROs. The use of urinary catheters also had a statistically significant association (P=0.031) with infection due to MDROs in this study. There was no statistically significant association between other variables and the incidence of MDROs in this study.

Table 4. Characteristics of sepsis patients with MDROs and non-MDRO culture results

*Significant risk factor at p<0.05

A statistically significant association was found (P= 0.024) in this study which assessed the association between the history of antibiotic use and the incidence of MDROs. A Korean study using data from 2004, 2008, and 2012 by Bongyoung et al. demonstrated the presence of microbial resistance due to an increased history of antibiotic use. An increase in A. baumannii resistance to imipenem (P=<0.001) correlated with increased carbapenem use, as well as E. coli or K. pneumoniae resistance to ciprofloxacin (P=0.001) correlated with carbapenem use. This supports the idea that increasing antibiotic resistance is caused by the increasing use of broad-spectrum antibiotics and antibiotics against MDR pathogens (20). In addition, the development of bacterial resistance to antibiotics is affected by the rapid evolution of the bacterial genome under selective antibiotic pressure and by selective pressure from the environment. Selective pressure from the continuous and routine use of antibiotics is the initial condition for increasing multi-resistant strains (21).
The use of urinary catheters significantly correlates (P=0.031) with infection due to MDROs in this study. A 2015 study by Nicolo et al. in Milan, Italy, showed a significant association between urinary catheter use and the incidence of MDROS with a P-value of 0.006. In addition, Nicolo et al. also studied other risk factors associated with ESBL + bacteria (P=0.008), one of which was the use of invasive devices that remain in the patient's body, such as urinary catheters, nasogastric tubes, and gastrotomy tubes (11). A study at Soetomo Surabaya General Hospital 2008 showed that patients with catheters were at risk of ESBL-producing E. coli and K. pneumoniae bacteria. This is because urinary catheters can cause germs to form ESBLs that are resistant to antibiotics (22). Urinary catheter use can cause bacterial colonization and produce biofilms that are persistent, recurrent, resistant to antibiotics, and can increase mortality. Moreover, inserting urinary catheters can cause urethral injury, which will be the site for bacterial adhesion, leading to the incidence of MDROs due to antibiotic resistance (23).
The fact that there was no statistically significant correlation between other variables and the incidence of MDROs in this study was caused by the different sensitivity patterns of the causative bacteria compared to other studies. In this study, the most common bacteria found in all specimens were K. pneumoniae, E. coli, and Staphylococcus aureus. In contrast, the specimens in this study were predominantly from sputum, blood, and urine.

Table 5. Logistic regression analysis (OR) of sepsis patients due to MDROs

Abbreviation: MDROs = multidrug-resistant organisms, OR = odd ratio, HIV = human immunodeficiency virus, N/A = not available. *Significant risk factor at P<0.05

It was concluded that the history of antibiotic use and the use of urinary catheters were the strongest factors affecting infection due to MDROs. The suggestion in this study is that antibiotics should be used wisely and rationally in the management of infectious patients. The use of urinary catheters should be done more selectively for inpatients to prevent the development of MDROs as a cause of infection, and further studies should be continued with a wider population of infectious patients, to analyze the factors that influence infection in various types of MDROs (ESBL, CRO, MRSA, VRE).

 

Thank you to the Education and Research Department of Dr. M. Djamil Padang General Hospital for supporting this research by providing input and consultation throughout the study. We also thank the laboratory of Dr. M. Djamil Padang General Hospital for supporting and assisting in providing data and information for the study.

 

Conflicts of Interest

The authors declared no conflict of interest.

Study concept and design: Fadrian; Supervision of the study: Fadrian, Linosefa; Materials: Fadrian, Linosefa, Muhammad Ridhwan F, Hidayatul Hasnah; Data collection and/or processing: Fadrian, Linosefa, Hidayatul Hasnah; Analysis and interpretation: Fadrian, Linosefa, Muhammad Ridhwan F; Literatur review: Fadrian, Linosefa; Writing: Fadrian, Linosefa, Muhammad Ridhwan F, Alya Syafa Ayuni; Critical review: Fadrian, Linosefa.

 

The Education and Research Department of Dr. M. Djamil Padang General Hospital funds this study.