In Vitro Biofilm Formation and Antibiotic Susceptibility Patterns of Bacteria from Suspected External Eye Infected Patients Attending Ophthalmology Clinic, Southwest Ethiopia

Bacterial foodborne illness and Escherichia coli O157:H7 strain infection among asymptomatic food handlers in Northeast Ethiopia: Implication for hygienic practices and mass-screening

Background and Aims

Food-borne illness is a public health concern in developing countries because of improper food handling and sanitation practices, irregular medical checkups, lack of clean water supplies, and inadequate education among food handlers. This study investigated the burden of bacterial food-borne illness, antibiotic resistance patterns, and associated factors among food handlers in prison and nonprison food establishment settings.

Methods

A cross-sectional study was conducted from August 2022 to January 2023 among asymptomatic food handlers in Shewa Robit town. A total of 384 food handlers participated. Data were collected using structured questionnaires. Stool and hand swab samples were collected and cultivated onto MacConkey agar, xylose-lysine-deoxycholate, Mannitol salt agar, and blood agar, and incubated at 37°C. Bacterial species were identified using biochemical tests and gram staining. Mueller-Hinton agar was used in Kirby Bauer's disk diffusion method. Data were entered and analyzed using SPSS. Descriptive and logistic regression analysis were performed.

Results

Fecal and hand carriage rate of bacterial isolates were 106 (27.6%), and 214 (55.7%), respectively. Out of the 102 bacterial isolates, the most common ones from stool samples were Escherichia coli 71 (18.5%), Klebsiella aerogenes 12 (3.1%), and Salmonella spp. 7 (1.8%). Among 214 bacterial isolates, coagulase-negative Staphylococci 115 (29.9%) and Staphylococci aureus 66 (17.3%) were identified from hand swab samples. Hand washing practice after restroom with water (adjusted odds ratio [AOR] = 2; 95% confidence interval [CI]: 1.16-3.45), irregular medical checkups (AOR = 2.49; 95% CI: 1.35-4.59), and did not receive food safety and hygiene training (AOR = 2.33; 95% CI: 1.34-4.05) were statistically significant association with food-borne illness.

Conclusions

Foodborne pathogens pose a serious health risk in the study areas. The level of antimicrobial resistance are also concerning. Food handlers should therefore get strict regular health education, medical checkups, and training programs to prevent the spread of infections to the customers.

Activity of biogenic silver nanoparticles in planktonic and biofilm-associated Corynebacterium pseudotuberculosis

Corynebacterium pseudotuberculosis is a gram-positive bacterium and is the etiologic agent of caseous lymphadenitis (CL) in small ruminants. This disease is characterized by the development of encapsulated granulomas in visceral and superficial lymph nodes, and its clinical treatment is refractory to antibiotic therapy. An important virulence factor of the Corynebacterium genus is the ability to produce biofilm; however, little is known about the characteristics of the biofilm produced by C. pseudotuberculosis and its resistance to antimicrobials. Silver nanoparticles (AgNPs) are considered as promising antimicrobial agents, and are known to have several advantages, such as a broad-spectrum activity, low resistance induction potential, and antibiofilm activity. Therefore, we evaluate herein the activity of AgNPs in C. pseudotuberculosis, through the determination of minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), antibiofilm activity, and visualization of AgNP-treated and AgNP-untreated biofilm through scanning electron microscopy. The AgNPs were able to completely inhibit bacterial growth and inactivate C. pseudotuberculosis at concentrations ranging from 0.08 to 0.312 mg/mL. The AgNPs reduced the formation of biofilm in reference strains and clinical isolates of C. pseudotuberculosis, with interference values greater than 80% at a concentration of 4 mg/mL, controlling the change between the planktonic and biofilm-associated forms, and preventing fixation and colonization. Scanning electron microscopy images showed a significant disruptive activity of AgNP on the consolidated biofilms. The results of this study demonstrate the potential of AgNPs as an effective therapeutic agent against CL.

Rutin/Sulfobutylether-β-Cyclodextrin as a Promising Therapeutic Formulation for Ocular Infection

Ocular pathologies present significant challenges to achieving effective therapeutic results due to various anatomical and physiological barriers. Natural products such as flavonoids, alone or in association with allopathic drugs, present many therapeutic actions including anticancer, anti-inflammatory, and antibacterial action. However, their clinical employment is challenging for scientists due to their low water solubility. In this study, we designed a liquid formulation based on rutin/sulfobutylether-β-cyclodextrin (RTN/SBE-β-CD) inclusion complex for treating ocular infections. The correct stoichiometry and the accurate binding constant were determined by employing SupraFit software (2.5.120) in the UV-vis titration experiment. A deep physical-chemical characterization of the RTN/SBE-β-CD inclusion complex was also performed; it confirmed the predominant formation of a stable complex (Kc, 9660 M-1) in a 1:1 molar ratio, with high water solubility that was 20 times (2.5 mg/mL) higher than the free molecule (0.125 mg/mL), permitting the dissolution of the solid complex within 30 min. NMR studies revealed the involvement of the bicyclic flavonoid moiety in the complexation, which was also confirmed by molecular modeling studies. In vitro, the antibacterial and antibiofilm activity of the formulation was assayed against Staphylococcus aureus and Pseudomonas aeruginosa strains. The results demonstrated a significant activity of the formulation than that of the free molecules.

Antimicrobial resistance pattern of Klebsiella isolated from various clinical samples in Ethiopia: a systematic review and meta-analysis

BACKGROUND

The burden of Klebsiella drug resistance to antimicrobials is a major public health concern worldwide; particularly the problem is severe in developing countries including Ethiopia. Therefore, the aim of this systematic review and meta-analysis is to establish the pooled estimate of Klebsiella drug resistance; and antimicrobial-specific resistance pattern among Klebsiella clinical isoaltes in Ethiopia.

METHODS

Articles were searched from PubMed, Google Scholar, and Science direct and grey literature from 2009 to 2019. Four authors have independently extracted data on the prevalence and antimicrobial resistance pattern of the isolates. Statistical analysis was conducted by using Open meta-analyst (version 3.13) and Comprehensive meta-analysis (version 3.3). The main outcome measures were the overall Klebsiella resistance; and drug-specific resistance patterns. A random-effects model was used to determine the pooled resistance prevalence with 95% confidence interval (CI), and significant heterogeneity was considered at p < 0.1; and I2 > 50% using DerSimonian and Laird method. In addition, subgroup analyses were conducted to improve the outcome.

RESULT

We obtained 174 potentially relevant studies through searching electronic databases, and finally, 35 eligible studies were included for meta-analysis. A total of 13,269 study samples participated, from which 1017 Klebsiella species were isolated. The overall Klebsiella resistance in Ethiopia was found to stand at 53.75% (95% CI: 48.35-58.94%). Based on the subgroup analyses; the highest (64.39%); and lowest (46.16%) values were seen in Southern Nations, Nationalities, and Peoples of Ethiopia; and Tigray regions respectively; and the highest Klebsiella resistance was reported to ampicillin (90.56%), followed by amoxicillin (76.01%) and trimethoprim-sulfamethoxazole (66.91%). A relatively low level of resistance rate was observed to amikacin (16.74%) and cefoxitin (29.73%).

CONCLUSION

The pooled Klebsiella resistance was found to be considerably high (53.75%) to most of the essential antibiotics in Ethiopia. Klebsiella was highly resistant to ampicillin and amoxicillin but relatively lower to amikacin. Therefore, appropriate interventional strategies need to be taken to address the emerging resistance of Klebsiella species.

Bacterial isolates, their antimicrobial susceptibility pattern, and associated factors of external ocular infections among patients attending eye clinic at Debre Markos Comprehensive Specialized Hospital, Northwest Ethiopia

Background

External eye infection caused by bacteria can lead to reduced vision and blindness. Therefore, pathogen isolation and antimicrobial susceptibility testing are vital for the prevention and control of ocular diseases.

Objective

The main aim of this study was to assess bacterial isolates, their antimicrobial susceptibility pattern, and associated factors of external ocular infection (EOI) among patients attended eye clinic at Debre Markos Comprehensive Specialized Hospital (DMCSH), Northwest Ethiopia.

Methods

We conducted a cross-sectional study in patients with external ocular infections from January 1, 2021, to June 30, 2021, at DMCSH. Socio-demographic and clinical data were collected using semi-structured questionnaires. Following standard protocols, external ocular swabs were collected and inoculated onto blood agar, chocolate agar, MacConkey agar and mannitol salt agar (MSA). Finally, bacterial isolates were identified by Gram stain, colony morphology, and biochemical tests. Antimicrobial susceptibility testing was done by using the modified Kirby-Bauer disk diffusion technique according to Clinical and Laboratory Standards Institute (CLSI) guideline. Cleaned and coded data were entered into EpiData version 4.2 software and exported to Statistical Packages for Social Sciences (SPSS) version 22 for analysis. Bivariate logistic regression was applied to investigate the association between predictors and outcome variables. P-values ≤ 0.05 with 95% confidence interval were considered statistically significant.

Results

Two hundred seven study participants were enrolled in this study. More than half of them (57.5%, 119/207) were males, and 37.7% (78/207) of them were ≥ 65 years old. A total of 130 (62.8%) bacterial isolates were identified, with Gram-positive bacteria accounting for 78.5% (102/130) of the isolates. Staphylococcus aureus was the most common isolate with a 46.2% (60/130) prevalence. Ciprofloxacin was comparatively effective against Gram-positive and Gram-negative bacteria. The prevalence of culture-confirmed bacteria was significantly associated with age groups 15–24 (AOR: 9.18, 95%CI: 1.01–82.80; P = 0.049) and 25–64 (AOR: 7.47, 95%CI: 1.06–52.31; P = 0.043). Being farmer (AOR: 5.33, 95% CI: 1.04–37.33; P = 0.045), previous history of eye surgery (AOR: 5.39, 95% CI: 1.66–17.48; P = 0.005), less frequency of face washing (AOR: 5.32, 95% CI: 1.31–7.23; P = 0.010) and face washing once a day (AOR: 3.07, 95% CI: 1.13–25.13; P = 0.035) were also significantly associated with the prevalence of culture-confirmed bacteria.

Conclusion

The prevalence of culture-confirmed bacteria among patients with EOI was high in the study area. A considerable proportion of bacterial isolates exhibited mono and/or multi-drug resistance. Age (15–64 years), being farmer, previous history of eye surgery and less frequency of face washing were significantly associated with the prevalence of culture-confirmed bacteria. Bacterial isolation and antibiotic susceptibility testing should be routinely performed in the study area to combat the emergence of antibiotic resistance.

In vitro evaluation of the antimicrobial activity of antiseptics against clinical Acinetobacter baumannii strains isolated from combat wounds

Healthcare-associated infections (HCAIs) are among the most prominent medical problems worldwide. In the context of increasing antibiotic resistance globally, the use of antiseptics as the main active agent and potentiator of antibiotics for the treatment of purulent-inflammatory complications of traumatic wounds, burns, and surgical wounds can be considered to tackle opportunistic infections and their prevention during war. This study presents a comparative investigation of the antimicrobial efficacy of antiseptics used for surgical antisepsis and antiseptic treatment of skin, mucous membranes, and wounds against multidrug-resistant clinical isolates of Acinetobacter baumannii as a wound pathogen of critical priority (according to the WHO). It was found that strains of A. baumannii, which have natural and acquired resistance to antimicrobial drugs, remain susceptible to modern antiseptics. Antiseptic drugs based on decamethoxine, chlorhexidine, octenidine, polyhexanide, and povidone-iodine 10% and 2% provide effective bactericidal activity against A. baumannii within the working concentrations of these drugs. Chlorhexidine and decamethoxine can inhibit biofilm formation by A. baumannii cells. In terms of bactericidal properties and biofilm formation inhibition, chlorhexidine and decamethoxine are the most effective of all tested antiseptics.

Clinical characteristics of external bacterial ocular and periocular infections and their antimicrobial treatment patterns among a Ghanaian ophthalmic population

Empirical antimicrobial therapy is linked to a surge in antimicrobial resistant infections. However, an insight on the bacteria etiology of ocular infections is essential in the appropriation of choice of antimicrobial among clinicians, yet there remains a dearth of data from Ghana. We investigated the bacteria etiology of external ocular and periocular infections and antimicrobial treatment patterns among a Ghanaian ophthalmic population. A multicenter study design with purposive sampling approach was employed. Patients demographics and clinical data were collated using a pretested structure questionnaire. Cornea specimens and conjunctival swabs were obtained for bacterial isolation following standard protocols. About 95% (98/103) of ocular samples were positive for bacteria culture. The proportion of Gram-negative bacteria was 58.2%, and the predominant bacteria species were Pseudomonas aeruginosa 38.8% and Staphylococcus aureus 27.6%. Conjunctivitis 40.0% and keratitis 75.0% were mostly caused by Pseudomonas aeruginosa. The routinely administered antimicrobial therapy were polymyxin B 41.2%, neomycin 35.1% and ciprofloxacin 31.6%. Participants demographic and clinical characteristics were unrelated with positive bacteria culture (p > 0.05). Our results showed a markedly high burden of ocular bacterial infections and variations in etiology. Bacterial infection-control and antimicrobial agent management programs should be urgently institutionalized to prevent the emergence of resistant infections.

Phenotypic and Genotypic Characterization of Antibiotic Resistance in Staphylococcus aureus Isolated from Different Sources

Background: Staphylococcus aureus is a bacterial pathogen that can cause a wide range of nosocomial infections. Nasal colonization by S. aureus plays an important role both in the epidemiology and pathogenesis of infection. Objectives: This study aimed at detecting the biofilm-forming capacity of clinical isolates and detection of icaA and agr genes. Methods: A total of 150 clinical specimens was collected from patients in different hospitals in Baghdad. The clinical samples included wounds, abscess, sputum, and ear infections. The suspected isolates were cultured for one day at 37 °C on mannitol salt agar in an aerobic environment. Results: The results showed that of 150 samples, 44 isolates were S. aureus (29.3%), of wounds samples, 22 isolates (45.83%) were S. aureus, 13 (37.14%) were from abscess, 7 (17.95%) from sputum, and 2 isolates (7.14%) from ear samples. This study found that most isolates formed biofilm, but the levels of biofilm were distributed across three ranges. The results also indicated that 47.7% of the isolates produced a strong biofilm, as well as 38.6 and 13.6% produced moderate and weak biofilms, respectively. The present molecular results showed that S. aureus from different samples were 13 (59.1%), 4 (30.77%), 3 (42.85%), 0 (0%) from wounds, abscess, sputum, ear, respectively, were positive for agr gene. While the results showed 18 (81.8%), 10 (76.9%), 5 (71.4%), 1 (50%), respectively, were positive for icaA gene. Conclusions: Most S. aureus isolates isolated from wound were biofilm positive. These isolates bore icaA and agr genes in a high quantity.

Bacterial profile and antimicrobial susceptibility patterns of isolates among patients diagnosed with surgical site infection at a tertiary teaching hospital in Ethiopia: a prospective cohort study

BACKGROUND

Globally, surgical site infections are the most reported healthcare-associated infection and common surgical complication. In developing countries such as Ethiopia, there is a paucity of published reports on the microbiologic profile and resistance patterns of an isolates.

OBJECTIVE

This study aimed at assessing the bacterial profile and antimicrobial susceptibility patterns of isolates among patients diagnosed with surgical site infection at Jimma Medical Center in Ethiopia.

METHODS

A prospective cohort study was employed among adult patients who underwent either elective or emergency surgical procedures. All the eligible patients were followed for 30 days for the occurrence of surgical site infection (SSI). From those who developed SSI, infected wound specimens were collected and studied bacteriologically.

RESULTS

Of 251 study participants, 126 (50.2%) of them were females. The mean ± SD age of the patients was 38 ± 16.30 years. The overall postoperative surgical site infection rate was 21.1% and of these 71.7% (38/53) were culture positive. On gram stain analysis, 78% of them were Gram-negative, 11.5% were Gram-positive and 10.5% were a mixture of two microbial growths. Escherichia coli accounted for (21.43%), followed by Pseudomonas aeruginosa (19.05%), Proteus species (spp.) 14.29%), Staphylococcus aureus (11.90%), Klebsiella species (11.90%), Citrobacter spp. (9.5%), streptococcal spp. (7.14%), Coagulase-negative S. aureus (CoNS) (2.38%) CONCLUSION: Gram-negative bacteria were the most dominant isolates from surgical sites in the study area. Among the Gram-negative bacilli, Escherichia coli were the most common bacteria causing surgical site infection. As there is high antibiotic resistance observed in the current study, it is necessary for routine microbial analysis of samples and their antibiogram.

Assessment of eugenol inhibitory effect on biofilm formation and biofilm gene expression in methicillin resistant Staphylococcus aureus clinical isolates in Egypt

Methicillin-resistant Staphylococcus aureus (MRSA) biofilm infection is a major threat in Healthcare facilities. The search for biofilm inhibitors is essential to overcome the antibiotic resistance. Eugenol is a phyto-compound that possesses many biological properties. In this study, the aim was to estimate the effect of eugenol on biofilms of MRSA through quantifying the level of gene expression of three genes (IcaA, IcaD and SarA) involved in biofilm development.. Fifty MRSA biofilm producers collected from the microbiology lab at Theodor Bilharz Research Institute were incubated with different concentrations of eugenol for 24 h. The minimum inhibitory concentration of eugenol (MIC) that eradicates the biofilms growth was detected. mRNA was extracted from all isolates before and after the application of eugenol at 0.5 x MIC, and then subjected to quantitative real-time PCR (qPCR). Results showed that fourteen isolates out of 50 (28%) exhibited intermediate biofilm formation ability, and 36 out of 50 (72%) were strong biofilm producers. The MIC values of eugenol for MRSA ranged from 3.125% to 0.01%. The mean values of MIC in both strong and intermediate biofilm forming MRSA isolates were statistically comparable (p = 0.202). qPCR results revealed that the levels of expression of the studied genes IcaA, IcaD, and SarA were decreased after eugenol treatment when compared with their corresponding values before treatment (p = 0.001). Eugenol inhibited the formation of biofilm of MRSA isolates, indicating it could be used to control infections associated with MRSA biofilms.