Avicenna Journal of Clinical Microbiology and Infection
Volume:9 Issue: 1, Mar 2022

Early detection of extended-spectrum β-lactamases (ESBLs) producing bacteria is critical for infection prevention and control. Numerous phenotypic approaches and automated systems have been developed for detecting ESBL bacteria. However, there is a scarcity of data in Ethiopia regarding the most reliable, simple, and cost-effective methods for detecting ESBL-producing bacteria. This study, therefore, aimed to evaluate the diagnostic performance of three phenotypic approaches for detecting ESBL-producing bacteria.

In this study, 117 isolates of Klebsiella pneumoniae, Escherichia coli, Klebsiella oxytoca, and Proteus mirabilis were examined. Cefotaxime (30 µg) and ceftazidime (30 µg) were used for screening ESBL enzymes. A screening breakpoints of≤27 mm and≤22 mm were used for cefotaxime (30 µg) and ceftazidime (30 µg), respectively, as per the Clinical and Laboratory Standards Institute (CLSI) guidelines. All 117 strains were further confirmed by the Vitek 2 compact, double disk synergy, ESBL Epsilometer test, and combined disk method. The combined disk method was adopted as the reference method.

Out of 117 isolates, 90 (86%) had zone diameters of≤27 mm and≤22 mm for cefotaxime (30 µg) and ceftazidime (30 µg), respectively. The reference method detected 76 (65%) ESBL isolates out of 117 ones. From among the three techniques (i.e., double disk synergy, Vitek 2 compact, and ESBL Epsilometer test), the double disk synergy method demonstrated overall sensitivity and specificity of 97.4% and 97.6%, respectively. Vitek-2, cefotaxime, and ceftazidime Epsilometer test indicated indeterminate results of 6.8%, 6.8%, and 5.1% respectively.

Double disk synergy was found to have the highest sensitivity and specificity for detecting ESBL isolates with no indeterminate results.

Actinobacteria are widespread and live in a variety of habitats. Today, these bacteria are very important due to the production of various secondary metabolites with different biological activities. The present study aimed to isolate strains of Actinobacteria from different habitats (the Persian Gulf, Gandom Beryan area in the Lut Desert, and some plant roots). The anticancer and antimicrobial activities of secondary metabolites of these isolates were also investigated.

Samples were taken from water of the Persian Gulf, soil of Gandom Beryan area in the Lut Desert, and plant roots. For isolation of Actinobacteria, samples were cultured in ISP2, ISP4, AIA, Gauze, M1, ISP3, and GYP media. Bacterial strains were identified based on the colony and bacterial morphology and confirmed using the specific primers for Actinobacteria. The anticancer and antimicrobial activities of crude metabolite extracts and supernatant of the isolates were evaluated on MCF-7 and Staphylococcus aureus PTCC 112 and Pseudomonas aeruginosa PTCC 1214 strains.

The results showed that the supernatants of 7 isolates (ga31, ez, sa, mar2, rz, ga33, and ga5) and the metabolite extracts of 4 strains (ga31, ga5, rz, and ez) had anticancer activity. Overall, ga31 was the best strain with anticancer activity of more than 75%. When evaluating the antimicrobial activity of bacterial secondary metabolites, we found that only two strains (ga31 and ga5) had antimicrobial activity against S. aureus PTCC 1112.

In general, strain ga31, which has high anticancer and antimicrobial activities, could be a good candidate for new trials in the pharmaceutical industry.

Chlorhexidine (CHX) is the gold standard chemical agent against oral pathogenic bacteria and is widely used for plaque/gingivitis control. The aim of the present study was to compare the effect of alcohol-based and alcohol-free CHX mouthwashes on oral microorganisms.

In the present in vitro study, the standard strains of four microorganisms present in the oral cavity were prepared, including Streptococcus mutans, Streptococcus sanguinis, Streptococcus salivarius, and Lactobacillus casei. The serial dilutions of CHX antimicrobial agents were obtained, and the level of minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) was determined using the broth dilution method. Finally, data were analyzed using the Kruskal-Wallis test, the Mann-Whitney U test, and SPSS-16.

The MIC values of 0.12% and 0.2% alcohol-free CHX and 0.2% alcohol-based CHX for S. mutans were 1.17, 0.48, and 0.24 µg/mL, respectively. The MBC values of 0.12% and 0.2% alcohol-free CHX and 0.2% alcohol-based CHX for S. mutans were 18.78, 7.81, and 7.81 µg/mL, respectively. The MIC and MBC values of the tested CHX mouthwashes for S. mutans were significant (P≤0.05).

Overall, the 0.2% alcohol-based CHX mouthwash had the highest antibacterial activity against gram-positive bacteria.

Recently, the rate of antibiotic resistance of Campylobacter has been reported to be increasing and the mechanism of this resistance has been reported to be related to the activity of efflux pumps. The purpose of this study was to isolate Campylobacter strains from domestic animals such as poultry and cows and evaluate the role of efflux pumps in antibiotic resistance property of them.

A total of 300 fecal samples were collected from poultry and cows and subjected to isolation of Campylobacter by preT-KB method. The isolates were identified and confirmed by phenotypic and genotypic methods and their antibiotic susceptibility was evaluated using the disk diffusion method. Efflux pump activity in the isolates was assessed by EtBr-agar cartwheel method and the presence of efflux pump cmeABC was evaluated in all isolates. Finally, the correlation between efflux pump activity and antibiotic resistance was evaluated in the isolates using inhibition of efflux pump activity of Phe-Arg β-naphthylamide.

Of all samples, 10 (3.3%) Campylobacter strains were isolated. Seven (70%) and three (30%) strains were isolated from poultry and cows, respectively. Of all isolates, 9 belonged to Campylobacter jejuni and 1 belonged to Campylobacter coli. The isolates were resistant to three antibiotics, namely Ciprofloxacin, Ceftriaxone, and Cefotaxime. Efflux pump activity was observed in all isolates; however, cmeABC genes were not present in all of them. In addition, resistance to Erythromycin and Ciprofloxacin was associated with efflux pump activity.

All Campylobacter isolates in the current study showed antibiotic resistance and the activity of efflux pumps could induce antibiotic resistance and decrease the antibacterial activity of many drug families in Campylobacter. In addition, the activity of efflux pumps can be considered a mechanism of antibiotic resistance and elimination of this activity might increase the effectiveness of antibiotics.

Cystic echinococcosis (CE), caused by the larval stage of the Echinococcus granulosus, is a common human and animal disease that occurs worldwide. This study aimed to investigate the clinico-epidemiological characteristics of patients with hydatid cyst in surgical cases from 2001 to 2019 in Qom hospitals.

This cross-sectional study was conducted in Qom province, the center of Iran, from 2001 to 2019. The study population included all cases with hydatid cyst who operated in governmental and private hospitals. The participants’ characteristics such as age, gender, occupation, place of residence, organ involved, clinical signs and, diagnosis and treatment methods were collected using a questionnaire. The statistical analysis was carried out using SPSS (version 23) software package.

The results revealed that 53.21% and 46.79% of patients were females and males, respectively. Most cases were uban residents (57.69%), and 62.18% of them were housewives. Liver involvement was the most common localization of hydatid cysts reported in 73.7% of patients. The main diagnostic procedures were computed tomography scanning and indirect hemagglutination (IHA). Abdominal pain was reported in 62.2% of cases, and the most common treatment method for the disease was surgical (84.6%). Further, recurrence occurred in 13.47% of patients.

The results of this study showed that the majority of patients with CE were housewives. Therefore, proper washing of fruits and vegetables is very important. To prevent the occurrence of CE, the public awareness level should be increased. In addition, educational programs must be conducted by the Ministry of Health to identify whether the control measures are needed in the high risk population.

The viable but non-culturable (VBNC) state is defined as an adaptive mechanism for microorganisms adjusting to stressful conditions. Although VBNC bacteria are alive and metabolically active, they are unable to grow on routine culture media. Nevertheless, the potential capacity of VBNC pathogens to retain virulence activity and further resuscitate into the culturable state in favorable conditions constitutes a major hazard to food safety and public health. Food processing, transformation, and storage, as well as non-thermal techniques, can provoke pathogens toward VBNC induction. The distinct characteristic of VBNC bacteria led to the emergence of novel culture-independent techniques to prevent the misinterpretation of food safety. To deepen our knowledge of the molecular aspect of the VBNC state, several mechanism-oriented studies investigated the metabolic activity of VBNC bacteria and their correlation with different stressful conditions. This review aims to discuss the molecular mechanisms and genomic factors underlying the induction and resuscitation of the VBNC state. The study will further highlight innovative detection methods to provide a comprehensive perspective for future studies in the emerging fields of research concerning VBNC state, food safety, and public health.

The rapid spread of the virus around the world is raising alarms among scientists to identify vulnerable people who are at greater risk of infection. In this regard, the present study aimed to determine the prevalence of severe acute respiratory syndrome coronavirus 2 in different blood groups.

To find relevant studies, a comprehensive and systematic search was conducted based on the PRISMA guidelines in international databases such as PubMed, Scopus, Web of Sciences, and Google Scholar by December 31, 2020.

After the audit and exclusion of double and unrelated studies, 19 articles were included in the analysis. The most prevalent blood types in alive patients were A and O which calculated the aggregate prevalence at - 39.06 (95% CI: 36.22-41.94) and 35.60 (95% CI: 32.48-38.79). In addition, patients with blood groups B and AB were less than two other groups. The aggregated/estimated prevalence was 7.72 (95% CI: 5.06-10.88) and 16.23 (95% CI: 12.86-19.91) for AB and B, respectively. The results for the deceased had a similar pattern that was high for blood types A and O.

The current meta-analysis validated different prevalence rates of blood group types in patients with COVID-19, confirming that types A and O blood groups are the most prevalent types of deaths and live patients.