Particularities of bacterial ecology of acute otitis media in an African subtropical country (Cote d'Ivoire)

Molecular Typing of Pseudomonas aeruginosa Isolates Collected in Abidjan Hospitals (Côte d'Ivoire) Using the Multiple-Locus Variable Number of Tandem Repeats Method

Background/objectives:Pseudomonas aeruginosa can cause community-acquired infections affecting various body sites. The present retrospective study investigated the genetic diversity of 173 isolates (166 clinical, 7 environmental) of P. aeruginosa collected from clinical pathology laboratories in Abidjan, Côte d'Ivoire (2001-2011). Methods: Multiple-Locus Variable Number of Tandem Repeats (VNTR) Analysis (MLVA) using 13 loci was applied to all isolates and compared to published MLVA data. The antibiotics status of the isolates was compiled when available and compared to published profiles. Results: Among 95 isolates analyzed for their antibiotics status, 14 displayed concerning resistance profiles: five multidrug-resistant (MDR) and nine extensively drug-resistant (XDR). MLVA typing revealed a high genetic diversity (>130 genotypes), with many genotypes represented by a single strain. Notably, thirteen clusters (≥4 related isolates) were observed. Some clusters displayed close genetic relatedness to isolates from France, Korea, and well-studied strains (ST560, LES and PA14). Comparative analysis suggested the presence of international high-risk MDR clones (CC233, CC111) in Côte d'Ivoire. Importantly, MLVA clustering revealed a close relationship of CC235-MDR strains with a locally identified cluster (group 9). Conclusions: These findings support MLVA as a reliable and cost-effective tool for low-resource settings, allowing the selection of relevant strains for future whole genome sequence analyses. This approach can improve outbreak investigations and public health interventions aimed at curbing MDR P. aeruginosa transmission within hospitals and at the national level.

Factors Associated with Otitis Media Among Pediatrics in Two Government Hospitals in Arba Minch, Southern Ethiopia

Background

Bacterial otitis media (OM) is a common infection among the pediatric community worldwide and is the first reason for prescribing antibiotics in pediatric practices. However, if not promptly diagnosed and appropriately treated, it may persist and cause severe intra- and extra-cranial hard-to-cure complications. Hence, knowing the magnitude, etiology, and antibiotic susceptibility profile is very important for the proper management.

Methods

A cross-sectional study was carried out in 312 pediatrics (1 to 18 years) attending the Ear Nose Throat outpatient departments of the two title hospitals from 25 February to 30th August 2022. Patients were chosen through a systematic random sampling method. Data were obtained by means of a semi-structured questionnaire. Samples were collected to identify the causative bacteria as per microbiological guidelines. The antibiotic susceptibility test was done according to the Kirby-Bauer disc diffusion; SPSS version 25 was used for the analysis.

Results

The overall prevalence of otitis media was 67.3% (n=210); CSOM showed a slight preponderance (n=107) Gram-negative bacteria and Gram-positive bacteria were present in 59.8% (n=137) and 40.1% (n=92), respectively. Otitis media was predominantly caused by S. aureus (n=52, 56.5%), followed by Proteus spp. (n=33, 24%). Gram-negative bacteria were highly resistant to co-trimoxazole, amoxicillin-clavulanic acid, piperacillin, and tetracycline, whereas their positive counterparts were considerably penicillin and co-trimoxazole resistant. Overall, 61.5 and 19.2% of the isolates were MDR and XDR, respectively. MRSA, MR-CoNs, and VRE were 38.4% (n=20), 17.1% (n=5), and 58.3% (n=12), respectively; 19.7% (n=25) of Gram-negative bacteria produced ESBL, and 7% (n=9) were carbapenem-resistant. History of exposure to loud noise [AOR=3.4; CI=1.14-10.23; P-value=0.028] and family history of smoking at home [AOR=2.9; CI=1.18-7.25; P-value=0.020] have the greatest odds of otitis media.

Conclusion

Overall, the prevalence of otitis media is showing an upward trend, and MDR among bacterial isolates is increasing alarmingly.

Antibiotic-Resistant Bacteria Are Major Threats of Otitis Media in Wollo Area, Northeastern Ethiopia: A Ten-Year Retrospective Analysis

Antibiotic resistance is an increasingly serious threat to human health that needs an urgent action. The aim of this study was to determine the prevalence and antibiotic susceptibility profiles of bacteria isolated from patient ear discharges suspected of otitis media. A retrospective analysis was performed using culture and antibiotic susceptibility test results of 1225 patients who visited Dessie Regional Health Research Laboratory from 2001 to 2011. Results showed a strong association (P < 0.001) between age and the risk of acquiring middle ear infection. The predominant bacterial isolates were Proteus spp. (28.8%), Staphylococcus aureus (23.7%), and Pseudomonas spp. (17.2%). Most of the isolated bacteria showed high resistance to ampicillin (88.5%), ceftriaxone (84.5%), amoxicillin (81.9%), and tetracycline (74.5%). About 72.5% of Proteus spp. and 62.2% of Pseudomonas spp. have developed resistance to one and more antibiotics used to treat them. This retrospective study also revealed the overall antibiotic resistance rate of bacterial isolates was increased nearly twofold (P = 0.001) over the last decade. Relatively, ciprofloxacin and gentamicin were the most effective antibiotics against all the isolates. In conclusion, antibiotic-resistant bacteria are alarmingly increasing in Wollo area, northeastern Ethiopia, and becoming a major public health problem in the management of patients with middle ear infection.

Bacterial profile and antimicrobial susceptibility patterns of otitis media in Ayder Teaching and Referral Hospital, Mekelle University, Northern Ethiopia

Middle Ear infection is a common problem for both children and adults particularly in resource limited countries. Nevertheless, in Ethiopia and particularly in the study area, there is scarcity of recent data that indicate the magnitude of the problem. Thus this study aimed to identify bacterial isolates and determine their drug susceptibility patterns from patients who had ear infection. Cross sectional study was carried out on patients with ear infection and who visited the Ear, Nose and Throat clinic of Ayder referral and teaching hospital from November 2014 to June 2015. Middle ear discharges were collected and processed for bacterial culture and antimicrobial susceptibility testing using standard bacteriological techniques. Clinical and demographic data were collected using standard questionnaire. Data were entered and analyzed using SPSS version 20 software and p value of < 0.05 was considered statistically significant. Of the total of 162 patients with ear discharges, 68.5 % were from rural areas, 71 % with chronic infection, 54.9 % referred cases and 67.3 % of them had decreased hearing status. Pathogens were isolated from 157 (98.2 %) of the patients with a total of 216 isolates. Staphylococcus aureus 46 (28.4 %), Proteus mirabilis 39 (24.1 %), Pseudomonas aeruginosa 27 (16.7 %), Klebsiella spp. and Haemophilus influenzae 18 (11.1 % each) were the dominant bacteria. Out of the individuals with ear infection, single and mixed bacterial infection was seen among 185 (90.7 %) and 59 (39.5 %) respectively. Age group of 0–5 years (p = 0.02), chronic patients (p = 0.042) and referred cases (p = 0.045) showed high bacterial isolates. High resistance was seen to most antibiotics. Ciprofloxacin, Gentamicin Norfloxacin and Erythromycin were effective against isolated bacteria. The overall multi drug resistance rate of bacteria in this study was 74.5 %. Prevalence of bacteria associated with otitis media and multidrug resistance was very high in the study area. Ciprofloxacin, gentamicin, norfloxacin and erythromycin can be used to treat otitis media. Treatment of patients should be based on antimicrobial susceptibility test to prevent complications, development of further antibiotic resistance and extra treatment costs.

Antimicrobial drug resistance among clinically relevant bacterial isolates in sub-Saharan Africa: a systematic review

BACKGROUND

Little is known about the prevalence of antimicrobial resistance (AMR) amongst bacterial pathogens in sub-Saharan Africa (sSA), despite calls for continent-wide surveillance to inform empirical treatment guidelines.

METHODS

We searched PubMed and additional databases for susceptibility data of key pathogens for surveillance, published between 1990 and 2013. Extracted data were standardized to a prevalence of resistance in populations of isolates and reported by clinical syndrome, microorganism, relevant antimicrobial drugs and region.

RESULTS

We identified 2005 publications, of which 190 were analysed. Studies predominantly originated from east sSA (61%), were hospital based (60%), were from an urban setting (73%) and reported on isolates from patients with a febrile illness (42%). Quality procedures for susceptibility testing were described in <50% of studies. Median prevalence (MP) of resistance to chloramphenicol in Enterobacteriaceae, isolated from patients with a febrile illness, ranged between 31.0% and 94.2%, whilst MP of resistance to third-generation cephalosporins ranged between 0.0% and 46.5%. MP of resistance to nalidixic acid in Salmonella enterica Typhi ranged between 15.4% and 43.2%. The limited number of studies providing prevalence data on AMR in Gram-positive pathogens or in pathogens isolated from patients with a respiratory tract infection, meningitis, urinary tract infection or hospital-acquired infection suggested high prevalence of resistance to chloramphenicol, trimethoprim/sulfamethoxazole and tetracycline and low prevalence to third-generation cephalosporins and fluoroquinolones.

CONCLUSIONS

Our results indicate high prevalence of AMR in clinical bacterial isolates to antimicrobial drugs commonly used in sSA. Enhanced approaches for AMR surveillance are needed to support empirical therapy in sSA.

Evaluation of concordance between the microorganisms detected in the nasopharynx and middle ear of children with otitis media

Studies of microorganisms involved in otitis media in children often use a nasopharyngeal sample as a proxy for the middle ear fluid to test for bacteria and viruses. The question is whether such studies provide an accurate estimate of the prevalence of microorganisms involved in otitis media. We performed a systematic review of the literature reporting on the concordance between test results of nasopharyngeal and middle ear fluid samples for the most prevalent microorganisms in children with otitis media. Our findings show that the concordances vary from 68% to 97% per microorganism. For the most prevalent microbes, positive predictive values are around 50%. Most negative predictive values are moderate to high, with a range from 68% up to 97%. These results indicate that test results from nasopharyngeal samples do not always provide an accurate proxy for those of the middle ear fluid. It is important to interpret and use results of such studies carefully.