Introduction

Children are highly susceptible to a multitude of infections, which are generally mild in nature.^1,2 Commonly known infections experienced by children are gastrointestinal infections, respiratory tract infections, and others. According to a literature review, it has been observed that the suspected risk factors include daycare attendance, premature birth of the child, duration of breastfeeding, environmental tobacco exposure, contaminated air within the house, and low-socioeconomic status.³

The frequency of such infections varies across age groups. ‘Nosocomial infections’ (NIs) or hospital-acquired infections, are responsible for causing major threats to the pediatric population, especially to the neonates.⁴ According to the global statistics, around 8.7% of the hospitalized cases suffer from NIs.⁵ Organisms such as gram-negative bacilli, coagulase-negative Staphylococci, coagulase-positive Staphylococci, Pseudomonas spp, and Streptococcus sp. are the main causes of NIs whereas the other prevalent bacterial species causing infections are Staphylococcus aureus, Escherichia coli (E.coli), Proteus mirabilis, and Klebsiella pneumoniae.⁶ During the treatment of these infections, high incidences of antibiotic resistance were observed.⁷ These infections can be managed only through proper surveillance, prevention of transmission, immunization, and counseling.⁸ A study conducted by Salman J et al. (2014) determined the antibiotics surveillance pattern in hospitalized pediatric patients in Bahrain and later distinguished with the European countries.⁹ The study inferred that the prescription of an antibiotic needs to be clinically justified with proper documentation in the case record.⁹ Due to the paucity of literature regarding pediatric bacterial infections and the antimicrobial resistance patterns in Bahrain, the present study assessed the most common microorganisms causing infections in the pediatric population and their antibiotic sensitivity patterns.

Materials and Methods

This was a prospective study conducted at Bahrain specialist hospital for a duration of 5 years (2014 to 2018). Clinical samples such as urine culture, urethral swab, stool samples, eye swabs, and throat swabs received from the patients were labeled using unique hospital numbers; demographic details such as age, gender, and nationality were recorded for each of the patients. Uniqueness in samples was identified based on sample number and culture. Analysis of twenty different cultures received from the patients was conducted by the Department of Microbiology, Bahrain Specialist Hospital. On culture, different types of bacterial species were obtained, identified, and antibiotic sensitivity was determined.

Procedure

Patient samples were obtained and transferred to the bacteriology laboratory following standard specimen collection and transport protocol. Clinical samples were cultured using different media— MacConkey agar, Sheep blood agar, Campylobacter charcoal agar, Selenite broth, Gardnerella vaginalis agar, Sabouraud dextrose agar, Thayer Martin agar, Neomycin anaerobic agar, Fluid thioglycollate broth, Salmonella Shigella agar, and Chocolate bacitracin agar (Saudi Prepared Media Laboratory Company Ltd, Saudi Arabia). Further, the plates were incubated according to the standard conditions unique to the organisms: 35°C for MacConkey agar, Sabouraud dextrose agar, Salmonella Shigella agar, and Mueller Hinton agar whereas, 43°C with 5% CO₂ for Campylobacter charcoal agar, 35°C with 5% CO₂ for Sheep blood agar, Chocolate agar, Chocolate bacitracin agar, Gardnerella vaginalis agar, and Thayer Martin agar, and 35 °C with 5% CO₂ in anaerobic agar with an anaerobic gas pack for Neomycin anaerobic agar and Sheep blood agar for throat swabs.

Subsequently, the majority of the cultured isolates were identified using Vitex automated analyzer (Vitex® bioMerieux, USA), whereas few isolates were identified manually based on the routine microbiological techniques, such as morphological characteristics on the culture plate, Gram staining, motility test, and biochemical characteristics analysis.¹⁰ Antimicrobial susceptibility profile of each isolate was assessed using disk diffusion method (6-mm disc, OXOID, UK) by Kirby-Bauer procedure and Vitex automated analyzer (Vitex® bioMerieux, USA).^11-13

Vitek GN ID was applied to identify Gram-negative bacilli, Vitek AST N204 was used for sensitivity testing of all Gram-negative bacilli except Haemophilus influenzae. For Gram-positive cocci, Vitek ASTGP67 was used except for Streptococcus group A, B, C, and G (since they are universally sensitive to penicillin and cephalosporins only, macrolides were examined by applying Kirby- Bauer method).

Antibiotic sensitivity analysis of the isolates was performed by the Kirby-Bauer method, and the culture-positive patients were divided into three groups, i.e.,‘0-4’, ‘5-9’ and ‘10-14’ years of age. ^10-13

Statistical analysis

Data was analyzed using R i386.3.5.1. and Microsoft Excel. Percentage was applied to calculate the prevalence of organisms over age groups, distribution & pattern of bacterial isolates, and antibiotic resistance in Gram-positive and -negative bacteria. Proportion test was used to calculate the prevalence of different bacterial isolates. And p < 0.005 was considered as statistically significant.

Results

A total of 1094 samples and 1146 organisms were received from 976 patients. Based on the age distribution, the majority of the positive culture samples belonged to patients within 5 years of age; female subjects were predominant in the study (533). Extended-spectrum beta-lactamases (ESBL), Campylobacter sp. and Methicillin-resistant Staphylococcus aureus (MRSA), and others were high under the age group of 0-4 years in both the genders (Table 1). Further, the prevalence of ESBL was significantly more in subjects of age group 0-4 and 5-9 years than the age group “10-14” (p value = 0.0013 and 0.0017, respectively). Also, the prevalence of MRSA was more significant in subjects of age group 0-4 years and 10-14 years than the subjects of age group “5-9” (p = 0.0019 and 0.0068, respectively).

Maximum samples were of urine (27.66%) followed by the throat (25.22%), wound (12.74%), and stool (10.3%) (Table 2). Streptococcus group A (26%) and E. coli (18.67%) were the chief microorganisms isolated from pediatric subjects. Gender-wise distribution revealed Streptococcus sp. Group A was predominant in males (30.84%), and E. coli in females (24.18%), whereas nation-wide distribution showed Streptococcus group A (31.05%) and E. coli (19.13%) were dominant among samples from Bahrain nationals. Similar observations were noted among the samples obtained from other nationals. (Table 3)

The antibiotic susceptibility analysis for Grampositive and -negative isolates have been represented in Table 4 (a & b). Specifically, Streptococcus Group A demonstrated 13.85% resistance towards erythromycin and 9.18% resistance towards clindamycin; E. coli demonstrated major resistance towards trimethoprim /sulfamethoxazole (22.97%) and amoxicillin/clavulanic acid (20.19%). The commonly-tested antibiotics for Gram-positive and -negative groups, susceptibility pattern of gentamicin antibiotic had a significant association with the type of isolate (p = 0.0001). The odds of susceptibility of Gram-negative isolates was 2.56 times higher for gentamicin antibiotic than Gram-positive isolates. Further, the susceptibility pattern of amoxicillin/clavulanic acid antibiotic was significantly associated with the type of isolate (p value <0.0001). The odds of susceptibility of amoxicillin/clavulanic acid antibiotic was 2.89 times more for Gram-positive isolates than the Gram-negative isolates. Similarly, the susceptibility pattern of ciprofloxacin and trimethoprim/ sulfamethoxazole antibiotics was significantly associated with the type of isolate (p value 0.0019 and 0.0004, respectively). Odds of susceptibility of ciprofloxacin antibiotic was 2.08 times more for Gram-negative isolates, whereas odds of susceptibility of trimethoprim/sulfamethoxazole was 2.29 times higher for Gram-positive isolates (Table 5 a, b, c).

Discussion

Microbial infections lead to morbidity and mortality in children younger than five years of age. This accounts for about 4 million deaths per year globally.¹⁴ In this study, an increased rate of infection was recorded among children within five years of age. E. coli (35.97%) and Streptococcus group A (52.98%) were the most common organisms isolated from clinical samples, which can be compared to a study conducted in Gulf cooperation countries (GCC) by Mahmoud et al. (2012). The study reported the prevalence of E. coli (44%) at a greater rate followed by Klebsiella pneumoniae (20%).¹⁵

The majority of the isolates were collected from urine and throat cultures. The predominant organisms obtained from urine culture were E. coli (53.63%) followed by E. coli ESBL (17.98%), whereas Streptococcus sp. Group A (89.27%) was the most common organism from the throat cultures. Several studies have stated that the main causative organism for causing urinary tract infections (UTI) as uropathogenic E. coli.16-18 Study by Tebruegge et al. (2011) depicted the data of co-existing meningitis in children <16 years with UTI. The commonest pathogen causing this infection was E. coli (67.4%).¹⁹ Similar observations were seen in Saudi Arabia.²⁰

The present research showed a high prevalence of ESBL, Campylobacter sp., MRSA under the age group of 0-4 years in both genders. In a five-year study, children of mean age 5.35 years reported how ESBL was the most common bacteria causing UTI, hospitalization, bacterial resistance.²¹ Similarly, Rezai et al.(2015) illustrated that 30.5% of isolated E. coli was an ESBL-producing strain.²² While another study by Roy et al.(2017) described a higher prevalence rate of MRSA strains in children under 12 years (63.7%).²³ Also the study results of Schiaffino et al. (2019) were in accordance with the present study findings for Campylobacter sp, where the species shows a higher prevalence of phenotypic resistance in children under five years of age.²⁴

While the dominance of Streptococcus group A sp. was more in males (31.05%) and E. coli in females (24.18%), similar observations were observed in a study conducted by Lin et al. where of the total cases, a high proportion of boys were infected with Streptococcus group A sp (1.29:1) whereas, in Patwardhan et al. study, E. coli was more prevalent in girls (74.1%).^25,26 The current research is one of its kind, as several gram-positive and gram-negative bacteria were isolated from different cultures, fluids, stains, swabs, etc. Urine and throat cultures were maximum in number, indicating the presence of opportunistic organisms. However, there are numerous studies that show the intake of different cultures depending on the symptoms of bacterial infection which can lead to ignorance of other underlying infections/causes of diseases.^21,27-29

Gram-positive isolates were highly susceptible to amoxicillin and trimethoprim/sulfamethoxazole, whereas Gram-negative isolates were more susceptive to gentamicin and ciprofloxacin, which is unique in this study. This pioneering study was conducted among the Bahrain population and has added valuable insights to the susceptibility patterns of the organisms infecting some of the Bahraini nationals. But E. coli being a gram-negative organism, demonstrated major resistance towards trimethoprim/sulfamethoxazole (22.97%) and amoxicillin (20.19%). A study by Mohmammed, reported similar results for gram-negative organisms having a lower susceptibility rate towards antibiotics like ampicillin, amoxicillin-clavulanic acid.³⁰ Streptococcus Group A demonstrated 13.85% resistance towards erythromycin and 9.18% resistance towards clindamycin which is partly similar to a study conducted in school children, where 48% of isolates were unsusceptible to erythromycin while none were for clindamycin.³¹

The study has its share of limitations, such as the assessment was conducted at a single hospital. Future studies could involve hospitals across Bahrain in order to obtain a comprehensive picture. Education and awareness among Clinical practitioners and parents are quintessential. Antimicrobial stewardship program is one such program that requires Practitioners to follow evidence-based prescriptions to safeguard the patient’s welfare.³²

Conclusion

Frequency and antimicrobial resistance patterns were reported for the first time in a pediatric population. Spanning over five years in Bahrain. The pattern of susceptibility demonstrated by the detected organisms was also unique as compared to reports from the GCC countries.

Further, the prevalence of bacterial infection and antimicrobial resistance can be controlled by the introduction of strong infection control programs and the usage of antimicrobials only on the Clinician’s prescription. Additionally, the role of clinical/ hospital pharmacists cannot be underestimated in educating children and their parents/guardians.

Funding Sources

Nil

Conflict of interest

None declared

Acknowledgment

Nil