Bacteriological Profile and Antimicrobial Susceptibility Patterns of symptomatic bloodstream infection in Dhaka City

1 Dept. of Microbiology, School of Biomedical Science, KhwajaYunus Ali University, Enayetpur, Sirajganj, Bangladesh; 2 Dept. of Infection Prevention & Control, Medlife Healthcare Limited, Dhaka, Bangladesh 3 Dept. of Microbiology, Popular Diagnostic Centre, Dhaka, Bangladesh 4 Faculty of Basic Medical and Pharmaceutical Science, University of Science and Technology Chittagong, Chittagong, Bangladesh; 5 Laboratory of Microbiology, Department of Botany, Jahangirnagar University, Savar, Bangladesh


INTRODUCTION
Blood is the connective tissue and indispensable for survival and proper functioning of human life. From limiting/clearing pathogens, providing nutrients, clotting wounds, dissemination of hormones, chemicals and toxin removals and antibiotics movement throughout our body, it plays a very important role in body survival and defence. Invasion by microorganisms in blood constitutes the critical issues in infectious disease. Microorganisms which are present in circulation of blood either transiently, continuously or intermittently, are a big threat to all organs inside our body [1]. The result of blood infection inside our body is genuine, quick results which may led to various organ disappointments, stun, passing (frequency of demise at 20% to 50%) and dispersed intravascular coagulation. Therefore, one of the significant facts of the laboratory is to identify and detect microbial pathogens on time [2].
For common bacterial isolates finding, blood culture techniques are used. The most common bacterial isolates are Staphylococcus aureus Salmonella paratyphi A, Salmonella typhi, Pseudomonas aeruginosa, E. coli, Klebsiella pneumoniae, Proteus spp, and β-hemolytic Streptococci [3].Blood culture vials and naked eye assessments once every 24 hour periods for the proof of development for 48 hours is considered as typical blood culture techniques and then the sub-culture on solid culture media the next day. Before the coverage, the negative vials cultures were further re-brooded for 5-days. Development has been occurred in the recent years in blood culture media, culture techniques in the frameworks which are completely machine driven [4]. By these frameworks, vials are screened This work is licensed under a Creative Commons Attribution 4.0 International License. every 8-10 minutes and a calculation of the final out is supported by evaluations of changes in relation to being developed. At present, the following frameworks are available: BD BACTEC®, Trek Diagnostic systems Inc., Inc., Becton Dickinson Microbiology systems, Durham, N.C. BacT/Alert®), Westlake, Ohio (ESP Sparks, OrganonTeknika®), and bioMerieux, Inc. Hazelwood, Mo. (Vital) [2]. The main differentiation is the growth detection which exists normally within the systems [4]. In the systems, to incubate sample vials, the incubation period is normally programmed for 5-7 days. Bacterial antimicrobial susceptibility profile of normally varies among population because of difference in geography, local practices of antimicrobial prescribing and resistant bacterial strain's prevalence to a given area [5].
This research was done to find out the bacterial profile in blood culture and anti-biogram resistance profile of the isolated pathogens. It was done to find out the profile of isolated pathogens and designs out of the clinical specimens collected from patients in a renowned diagnostic center in capital city, Dhaka. Guiding the clinicians to initiate pragmatic antimicrobial therapy and to formulate a proper policy on antibiotic was the main objective of the research.

METHODOLOGY: STUDY AREA AND POPULATION:
The data was collected from the Microbiology Lab of Popular Diagnostic Center which included outdoor-patients with acute febrile illness between July 2020 and September 2020. Blood samples (n=305) were collected from suspected patients aseptically with bloodstream infection among entire aged group. About 3 ml of venous blood for children and 10 ml for adults was collected aseptically using 70% alcohol and 2% tincture of iodine and then transferred into a BD BACTEC TM culture bottle according to the manufacturer guideline.

BLOOD SAMPLING AND LABORATORY INVESTIGATIONS:
The protocol was approved by the Ethical Review Committee of Popular Diagnostic Centre, Dhaka, Bangladesh. All the samples were taken aseptically for culture in an automated system. In this research, only aerobic cultures of blood were used. A 1-5 ml amount blood samples were inoculated properly into BD BACTEC TM FX40 Peds Plus/F for 0-12 year-old children and 8-10 ml amount of blood samples were inoculated properly into BD BACTEC TM FX40 Aerobic/F for adults more than 12 years old. The clinical samples were then incubated quickly at 35±2ºC in the BD BACTEC TM FX40 Instrument for a maximum of 3 days unless the result flagged positive. The vials which gave a positive result were then sub-cultured on Blood agar and MacConkey agar followed by CLSI routine microbiological techniques [6].

BIOCHEMICAL & SEROLOGICAL ANALYSIS AND GRAM STAINING:
Simon citrate agar tubes, MIU, Klignar Iron Agar (KIA) and Oxidase tests were done for biochemical analysis to identify pathogens. Specific antisera (Becton, Dickinson and Company, Spark, USA) was used for confirmation of Salmonella spp. For distinguishing between Gram positive and negative bacteria, Gram staining methods were done [7].

STATISTICAL ANALYSIS OF EXPERIMENTAL DATA:
Excel 2016 and SPSS version 20 were used for analyzing the data. Descriptive statistics and chi-square tests were done for checking the statistical evaluation. <0.5 was the significant value of the p-value considered in this research.

RESULT AND DISCUSSION:
Blood infection has become very challenging; it is sometimes life threatening; that's why timely detection, identification, and antimicrobial sensitivity testing of blood-borne pathogens are very important in diagnostic microbiology laboratory. The physicians prescribe antimicrobial more than the actual need in developing countries like Bangladesh. All kinds of antibiotics are easily available in any medicine shop and anybody can buy it without doctor's prescription which are mainly responsible for developing resistant bacteria as well as blood culture negative results [8].
This work is licensed under a Creative Commons Attribution 4.0 International License.

Fig-1: Frequency of bacterial isolates in suspected samples
The positive samples belonged maximum to adults comparing to children which is also found in the study of Iqbal H et al, 2020 [8].
In this research, Nalidixic Acid showed 100% resistance to Salmonella typhi as well as Salmonella paratyphiA which is a very serious issue. Ceftriaxone and Ceftazidime showed 100% sensitivity to Salmonella paratyphi A bacteria and Ceftriaxone, Cefixime, Ceftazidime, Ciprofloxacin showed 100% sensitivity to Salmonella typhi. Antibiotic susceptibility test illustrated that the most sensitive antibiotics against Salmonella spp. were Ceftriaxone, Ceftazidime, Ciprofloxacin, Cefixime and Cefurixime and Staphylococcus spp were Ciprofloxacin, Gentamicin, Imepenem, Amoxicillin with a susceptibility rate of 100%. Relatively similar result for Staphylococcus spp. was found in Abedin MZ et al 2020 [5]. For Pseudomonas spp. Imepenem showed tremendous susceptibility but showed the least effect against Amoxicillin. The pattern of antibiotic resistance of all organisms was predicated in the Table  2 and Table 3.

CONCLUSION:
In the conclusion, we have performed blood culture by automated BD BACTECTM TM -40 and in vitro analysis of antibiogram patterns from the patients who were suffering from acute febrile illness sought treatment at tertiary level hospital in Bangladesh. The blood culture analysis revealed 31.47% positive bacteremia patients with numbering of suspected isolates were Staphylococcus aureus, Salmonella typhi, Salmonella paratyphi A, Salmonella spp and Pseudomonas spp. The fourth generation antibiotic Ceftriaxone, Cefixime, Ceftazidime etc showed higher susceptibility to almost all organisms, but Nalidixic acid showed least sensitivity. Very careful consideration needs to be taken before selecting the appropriate antibiotic for the treatment. Serious concern is imposed by presence of antibiotic resistant organism regarding antibiotic choosing for the treatment of patient with bacteremia.

AUTHORS CONTRIBUTIONS
Abedin MZ and Ahmed AA designed the experiments, Ahmed F collected the samples and analyzed, Yeasmin F carried out the study, Abedin MZ and Shilpi RY participated in design to draft, and Zaman MSU wrote the manuscript. Abedin MZ and Shilpi RY supervised and reviewed the manuscript; all the authors read and approved the final manuscript.

ETHICS APPROVAL AND CONSENT TO PARTICIPATE
Not applicable.

HUMAN AND ANIMAL RIGHTS
Not applicable.

CONSENT FOR PUBLICATION
Not applicable.

AVAILABILITY OF DATA AND MATERIALS
None.

FUNDING
None.