International Journal of Microbiology

The indiscriminate use of antibacterial agents has resulted in one of the largest recent global health problems, which is the emergence of bacterial resistance. This study aimed to examine the antimicrobial and antioxidant activities of ethanolic extracts of the two medicinal plants; Rosmarinus officinalis pods and Thymus vulgaris leaves on Escherichia coli urinary isolates. Both plants were extracted by absolute ethanol, and various concentrations (100, 50, 25, and 12.5 mg/ml) of the ethanolic extracts were prepared and tested against 53 urinary isolates of E. coli. An antibiotic susceptibility test was performed using chloramphenicol, gentamycin, amoxicillin, ceftriaxone, and ciprofloxacin against isolated bacteria. The antioxidant activity was measured using the DPPH method. The chemical analysis of both extracts was determined using gas chromatography-mass spectrometry (GC/MS) technique. The results showed that 88.7% of the isolated bacteria were sensitive to chloramphenicol and 87% were sensitive to gentamycin, while all isolates were resistant to amoxicillin, 13% of E. coli isolates were found to be multidrug-resistant (MDR). The inhibitory zone of R. officinalis extract against E. coli ranged between 8 and 23 mm and for T. vulgaris extract ranged between 8 and 20 mm at concentrations between 25, 50, and 100 mg/ml. The MIC of both extracts against isolates is between 12.5 and 50 mg/ml, while the MBC is between 50 and 100 mg/ml. The DPPH radical scavenging potential of T. vulgaris was 83.09%, followed by R. officinalis (81.26%). The chemical analysis by GC-MS of R. officinalis showed that the most active compounds were: eucalyptol (18.57%), bicycloheptan (10.01%), and octahydrodibenz anthracene (7.44%) and for T. vulgaris the most active compounds were: thymol (5.7%), phytol (7.92%), and hexadecanoic acid (18.51%). R. officinalis and T. vulgaris ethanolic extracts possessed antimicrobial and antioxidant activities and were found to be rich natural sources of active constituents used as traditional medicine.

Introduction. Tonsillitis is the third most frequently diagnosed infection in the pediatric age and is associated with significant morbidity and loss of school attendance. Throat swab cultures are useful for the confirmation of children with a clinically suspected tonsillitis. However, Somaliland is one of the underdeveloped countries with a low standard of sanitation and poor health seeking culture. Treatment of tonsillitis with antibiotics is irrational and not empirical. This study determined the bacterial throat swab culture positivity and antibiotic resistance profiles of the bacterial isolates among children 2–5 years of age with suspicion of tonsillitis at Hargeisa Group of Hospital, Somaliland. Materials and Methods. A cross-sectional study was conducted from March to July 2020. A total of 374 children from 2 to 5 years of age suspicion of tonsillitis was included using a convenient sampling method. Throat swabs were collected, and bacterial isolation and identification were done using standard bacteriological procedures. Antimicrobial susceptibility testing was done using the disk diffusion method. Data on demographic variables and clinical profiles were collected using structured questionnaires. Logistic regression analysis was computed to identify factors associated with bacterial tonsillitis. Results. Overall, 120 (32.1%) (95% CI 27.4–36.8%) of children were positive for bacterial throat cultures. Of these, 23 (19.2%) were mixed bacterial isolates. The most frequent bacterial isolates were beta-hemolytic streptococci 78 (55%), Staphylococcus aureus 42 (29%), and Streptococcus pneumoniae 10 (7%). Isolates revealed 83.3–100% rate of resistance to ampicillin. Beta-hemolytic streptococci isolates were 94.9% resistant to ampicillin. S. aureus was resistant to clarithromycin (38%) while S. pneumoniae isolates were 100% resistant to ampicillin. History of tonsillitis (AOR = 0.12; 95% CI = 0.06–0.21), difficulty in swallowing (AOR = 6.99; 95% CI = 3.56–13.73), and attending schools (AOR = 2.98; 95% CI = 1.64–5.42) were found to be associated with positive throat culture. Conclusions. Resistance to ampicillin and MDR among beta-hemolytic streptococci and other isolates of throat colonizers in children with clinically suspected of bacterial tonsillitis are major concerns in Hargeisa, Somaliland. Therefore, treatments of cases are recommended to be guided by regular culture and antimicrobial susceptibility testing to prevent complications of tonsillitis and associated antibiotic resistance.

Campylobacter organisms are the major cause of bacterial gastroenteritis and diarrhoeal illness in man and livestock. Campylobacter is growingly becoming resistant to critically crucial antibiotics; thereby presenting public health challenge. This study aimed at establishing antimicrobial use, susceptibility profiles, and resistance genes in Campylobacter isolates recovered from chicken, cattle, and cattle-trough water samples. The study was conducted between October 2020 and May 2022 and involved the revival of cryopreserved Campylobacter isolates confirmed by PCR from a previous prevalence study in Kajiado County, Kenya. Data on antimicrobial use and animal health-seeking behaviour among livestock owners (from the same farms where sampling was done for the prevalence study) were collected through interview using a pretested semistructured questionnaire. One hundred and three isolates (29 C. coli (16 cattle isolates, 9 chicken isolates, and 4 water isolates) and 74 C. jejuni (38 cattle isolates, 30 chicken isolates, and 6 water isolates)) were assayed for phenotypic antibiotic susceptibility profile using the Kirby–Bauer disk diffusion method for ampicillin (AX), tetracycline (TE), gentamicin (GEN), erythromycin (E), ciprofloxacin (CIP), and nalidixic acid (NA). Furthermore, detection of genes conferring resistance to tetracyclines (tet (O), β-lactams (bla_OXA-61), aminoglycosides (aph-3-1), (fluoro)quinolones (gyrA), and multidrug efflux pump (cmeB) encoding resistance to multiple antibiotics was detected by mPCR and confirmed by DNA sequencing. The correlation between antibiotic use and resistance phenotypes was determined using the Pearson’s correlation coefficient (r) method. Tetracyclines, aminoglycosides, and β-lactam-based antibiotics were the most commonly used antimicrobials; with most farms generally reported using antimicrobials in chicken production systems than in cattle. The highest resistance amongst isolates was recorded in ampicillin (100%), followed by tetracycline (97.1%), erythromycin (75.7%), and ciprofloxacin (63.1%). Multidrug resistance (MDR) profile was observed in 99 of 103 (96.1%) isolates; with all the Campylobacter coli isolates displaying MDR. All chicken isolates (39/39, 100%) exhibited multidrug resistance. The AX-TE-E-CIP was the most common MDR pattern at 29.1%. The antibiotic resistance genes were detected as follows: tet (O), gyrA, cmeB, bla_OXA-61, and aph-3-1 genes were detected at 93.2%, 61.2%, 54.4%, 36.9%, and 22.3% of all Campylobacter isolates, respectively. The highest correlations were found between tet (O) and tetracycline-resistant phenotypes for C. coli (96.4%) and C. jejuni (95.8%). A moderate level of concordance was observed between the Kirby–Bauer disk diffusion method (phenotypic assay) and PCR (genotypic assay) for tetracycline in both C. coli (kappa coefficient = 0.65) and C. jejuni (kappa coefficient = 0.55). The study discloses relatively high resistance profiles and multidrug resistance to antibiotics of critical importance in humans. The evolution of the multidrug-resistantCampylobacter isolates has been linked to the use and misuse of antimicrobials. This poses a potential hazard to public and animal health, necessitating need to reduce the use of antibiotics in livestock husbandry practice coupled with stringent biosecurity measures to mitigate antimicrobial resistance.

Background. Methicillin-resistant Staphylococcus aureus (MRSA) is a major bacterial pathogen. Aim. The present study aimed to determine the incidence of MRSA infections among kidney dialysis patients and the antibiotic susceptibility patterns and investigate the prevalence of mecA gene among MRSA isolates. Materials and Methods. A total of 83 nasal sterile cotton swabs samples were obtained from hemodialysis patients from Al-Karak Governmental Hospital, Al-Karak, Jordan. Collected and cultured on nutrient agar and mannitol salt agar and incubating at 37°C for 24–48 hours, Staphylococcus aureus (S. aureus) strains were identified by gram stain, coagulase test, and catalase tests. The MRSA isolates were tested for the presence of MecA and SCCmec genes using the Xpert SA Nasal Complete assay real-time PCR. Factors such as age and gender were included in the study. The antibiotic profile tested by using the disc diffusion method tested all MRSA isolates. Results. This study showed that 10.8% of the cultures’ growth was S. aureus and 9.6% of all the patients were infected with MRSA, with no relationship between the number and frequency of MRSA according to the patient’s gender or age. All MRSA (100%) isolates have both genes (MecA genes and SCCmec genes), and all samples were resistant to oxacillin, ceftazidime, cefoxitin, aztreonam, and ampicillin. Conclusion. The MRSA prevalence was determined among kidney dialysis patients in the hospital. All positive samples were resistant to oxacillin, ceftazidime, cefoxitin, aztreonam, and ampicillin, which is a very rare finding, and this will give the scientists and doctors a dangerous indication about health-care centers in the Al-Karak city of Jordan.

Background. External ocular infection is a global public health problem. Frequently, bacteria cause an ocular infection that ranges from morbidity to loss of vision. The increasing bacterial resistance in ocular infections leads to the risk of treatment failure with possibly serious consequences. Objective. The study aimed to assess the bacterial profile of external ocular infections, their associated factors, and antimicrobial susceptibility pattern among patients admitted to Karamara hospital, Jigjiga, Eastern Ethiopia. Method. Institutional-basedcross-sectional study was conducted on 288 conveniently selected patients among patients admitted to Karamara hospital from May 1 to June 30, 2020. Data were collected using a structured questionnaire. The ocular sample was collected and cultured in the appropriate culture media and identified using a series of biochemical tests. Antimicrobial susceptibility testing of isolates was performed by using the disk diffusion method. Data were double entered onto EpiData version 3.1 then exported to SPSS version 20 and analyzed to calculate descriptive frequency and odds ratio, and value ≤0.05 was taken as the significant value. Result. The prevalence of bacterial infection in external ocular samples was 62.2% (95% CI: 56.6%, 68.4%). Out of the 179 isolates, the majority of the bacterial isolates (87.7%) were Gram-positive. Staphylococcus aureus (53.1%) was the predominant isolate. Using soap for washing the face (AOR = 0.43; 95% CI: 0.29, 0.95), having diabetes mellitus (AOR = 3.11; 95% CI: 1.45, 6.75), and history of hospitalization (AOR = 2.82; 95% CI: 1.44, 5.54) were significantly associated with external ocular infection. Most (95.5%) of the Gram-positive bacteria showed resistance to penicillin, but they were susceptible to vancomycin, clindamycin, and ciprofloxacin. Conclusion. The study showed a high prevalence of bacterial infections with the predominant isolate was S. aureus. Penicillin-resistant bacteria were identified among Gram-positive bacterial isolates. Soap usage, hospitalization, and diabetes mellitus were associated with the infection. Antibiotics that were susceptible to the specific bacteria should be used as a drug of choice and using soap for washing the face is advisable to protect against external ocular infection.

Bitis arietans (Puff adder), Naja haje (Egyptian cobra), and Naja pallida (Red spitting cobra) venoms were tested for antimicrobial activity. This evaluation employed disc diffusion and microbroth dilution techniques. Gram-positive bacteria (Bacillus cereus and Staphylococcus aureus) and Gram-negative bacteria (Escherichia coli, Klebsiella pneumonia, and Salmonella typhi) were used. Aztreonam (30 µg), cefpodoxime (10 µg), cefoxitine (30 µg), streptomycin (25 µg), ceftriaxone (30 µg), nalidixic acid (30 µg), tetracycline (30 µg), and sulfamethoxazole (25 µg) were used as controls. All tests were conducted in triplicate (n = 3). Results. The activity of B. arietans venom against Gram-negative bacteria was significantly lower () than that of controls. The efficacy of B. arietans venom and sulfamethoxazole against both Gram-positive and Gram-negative bacteria was not significantly different (). The efficacy of B. arietans venom against Gram-positive bacteria was significantly lower () than cefoxitin, streptomycin, and tetracycline. The efficacy of N. haje venom against Gram-negative bacteria was significantly lower () than that of controls. There was no significant difference in the antimicrobial efficacy of N. haje venom and controls against Gram-positive bacteria ( to ). There was no significant difference in the efficacy of N. pallida venom and controls against Gram-negative bacteria ( to ). There was no significant difference in the efficacy of N. pallida venom and controls against Gram-positive bacteria ( to ). Conclusions. Of all the tested venoms, only Naja pallida venom showed good efficacy against both Gram-positive and Gram-negative bacteria.