Vol 14 No 4 (2022)

Invited Commentary

Original Article(s)

  • XML | PDF | downloads: 220 | views: 309 | pages: 438-444

    Background and Objectives: Carbapenem-resistant Acinetobacter baumannii has recently been identified by the World Health Organization as a critical pathogen. We propose to characterize the molecular characteristics of clinical isolates of A. baumannii resistant to carbapenems collected in a Moroccan hospital.
    Materials and Methods: Seventy carbapenem-resistant A. baumannii isolates from various samples were received at the microbiology laboratory of the Hospital Center. Antibiotic susceptibility was tested by the diffusion disc method and molecular characterization of antimicrobial resistance was performed by PCR and sequencing.
    Results: Carbapenemase genes were detected in our isolates: the OXA-51 gene and the ISbA1 sequence were detected in all isolates (100%), the OXA-23 and OXA-58 genes were detected in 82.85% and 10% of isolates respectively, MBL genes were dominated by VIM 39 isolates (55.7%), followed by GIM 26 isolates (37%), SIM 20 isolates (28.5%), IMP 8 isolates (11, 4%), NDM 3 isolates (4%) and for the first time in Morocco SPM with 4 isolates (5.7%).
    Conclusion: The emergence of resistance of A. baumannii to carbapenems is a serious problem in our hospital which requires the establishment of a prevention strategy and strict respect for hygiene to minimize their dissemination.

  • XML | PDF | downloads: 243 | views: 499 | pages: 445-457

    Background and Objectives: Uropathogenic Escherichia coli (UPEC) is divided into different phylogenetic groups that differ in their antibiotic resistance patterns, serogroups and pathogenicity. This study aimed to investigate the prevalence of phylogenetic groups of UPEC isolates and their relationship with serogroups and virulence factors in patients with UTIs.
    Materials and Methods: Of the 412 urine samples tested a total of 150 UPEC were isolated and confirmed with PCR using 16S rRNA gene. Antibiotic resistance of the isolates was tested using disk diffusion method and the isolates were divided into phylogenetic groups by the quadruplex PCR method. The prevalence of serogroups and virulence genes were investigated using multiplex PCR.
    Results: 87 (58%) of the isolates belonged to phylogroup B2. Virulence genes fimH (95.3%), aer (49.3%) and serogroups O8 (22.3%), O25 (21.5%) showed the highest prevalence. The lowest drug resistance was observed against imipenem (4.6%) and meropenem (3.3%). The prevalence of multidrug-resistant and extended-spectrum beta-lactamases isolates were 60% and 61.3%, respectively. We also found a significant relationship between phylogenetic groups, serogroups and virulence factors among our isolates.
    Conclusion: The high abundance of phylogenetic group B2, serogroups O8 and O25, and virulence genes fimH and aer indicate their importance in the pathogenesis of UPEC in this country.

  • XML | PDF | downloads: 330 | views: 497 | pages: 458-465

    Background and Objectives: We compared two common antibiotic regimens for the treatment of mild to moderate CAP: levofloxacin versus β-lactam and macrolide combination; in terms of their efficacy and side effects.
    Materials and Methods: Patients with mild to moderate CAP were randomized into two groups. Group I received a combination of 1 gram ceftriaxone daily and 500 mg azithromycin daily for 5-7 days. Group II received levofloxacin 750 mg daily for five days. The signs and symptoms, hospitalization length, and the side effects were investigated.
    Results: There were 77 and 74 patients in groups I and II. The vital signs of group II were significantly better on the 3rd day of admission, except for the temperature (P=0.09). The O2 saturation of group II was markedly improved on the 5th day of admission (P=0.0061). In terms of clinical symptoms and hospitalization length, group II was considerably better. However, the rate of side effects in both groups was similar (P=0.885).
    Conclusion: Hospitalized patients with mild to moderate CAP might take more advantage of fluoroquinolone administration. It could improve the patients' signs and symptoms and reduce hospitalization length, compared with the combination of macrolide and cephalosporin, with the same rate of side effects.

  • XML | PDF | downloads: 131 | views: 250 | pages: 466-474

    Background and Objectives: Escherichia coli (E. coli) is an important member of Enterobacteriaceae family involved in severe infections. The increased rate of resistance towards different classes of antibiotics limits their treatment options. The aim of this study was to assess the in vitro activity of classical and novel combinations of β-lactam/ β-lactamase inhibitor against E. coli clinical isolates.
    Materials and Methods: 140 clinical isolates of E. coli were collected from clinical specimens from Gastrointestinal Surgery Center (GISC) in Egypt. Extended spectrum β-lactamase (ESBL) was detected by double disk synergy test. Furthermore, the minimum inhibitory concentrations (MICs) for five different combinations were determined using the broth microdilution method including: amoxicillin/clavulanate and ampicillin/sulbactam as an example for classical combinations and cefoperazone/sulbactam, ceftazidime/avibactam, and cefepime/enmetazobactam as an example for new combinations.
    Results: The percentage of ESBL production among the tested isolates was 46.4%. Isolates were highly resistant to classical β-lactam/ β-lactamase inhibitor combinations, where (40.7%) and (42.9%) of isolates were resistant to amoxicillin/clavulanate and ampicillin/sulbactam, respectively. While new β-lactam/ β-lactamase inhibitor combinations had promising inhibitory action. The addition of novel β-lactamase inhibitors restored the susceptibility of isolates, where (94.3%) of isolates became susceptible to ceftazidime/avibactam combination, followed by cefoperazone/sulbactam (89.2%) and cefepime/enmetazobactam (85.7%). The synergistic effect seems to be effective where ceftazidime and avibactam were synergistic in 80% of isolates.
    Conclusion: The antibacterial activity of some antimicrobial agents can be enhanced by the addition of new β-lactamase inhibitors. Further in vivo investigation is needed to confirm their therapeutic efficacy against local isolates.

  • XML | PDF | downloads: 138 | views: 317 | pages: 475-483

    Background and Objectives: To provide data on the occurrence of classical K. pneumoniae (cKp) and hypervirulent Klebsiella pneumoniae (hvKp) strains harboring the gene encoding regulator of mucoid phenotype A (rmpA) and evaluated characteristics of virulence biomarkers, carbapenemase, extended-spectrum-β-lactamase (ESBL)-producing, and capsule serotypes among K. pneumoniae clinical isolates collected in the south of Iran.
    Materials and Methods: A total of 400 K. pneumoniae isolates were collected. First, the K. pneumoniae isolates were screened for rmpA gene by PCR, and then they were characterized for the presence of the virulence genes (pagO, iucA, iroB, luxR), capsular serotype genes (K1, K2, K5, K20, K54, and K57), carbapenemase (blaNDM, blaIMP, blaVIM, blaKPC, blaSPM, blaOXA-48, and blaOXA-181) and ESBL (blaCTX-M, blaSHV and blaTEM) genes. For all K. pneumoniae isolates phenotypic tests include of string test and disk diffusion test were performed.
    Results: In total, 16 (4%) hvKp-rmpA+ and 384 (96%) cKp were observed. Of hvKp-rmpA+ strains, 16 (100%) were carried pagO, iroB, and luxR genes, and 13 (81.3%) strains harbored iucA gene. The most prevalent capsular type genes were K1 (62%) and K2 (19%) in hvKp-rmpA+ strains. The incidence of blaSHV gene in hvKp and cKp was 94% (15/16) and 87.5% (336/384), respectively. The cKp isolates carried blaNDM (30/384; 7.8%) gene.
    Conclusion: Our data suggest that the incidence of hvKp was low. Also, hvKp-rmpA+ strains have less antibiotic resistance than cKp isolates. Serotypes K1 and K2, and blaSHV gene were strongly associated with hvKp-rmpA+.

  • XML | PDF | downloads: 178 | views: 331 | pages: 484-494

    Background and Objectives: With the increase in immunosuppressed patients and antimicrobial misuse, Bacillus species have risen as opportunistic pathogens in hospitalized patients. The present study aimed at comparing chromogenic media, automated identification cards versus MALDI-TOF as the gold standard method for identification of different Bacillus species and determining minimal inhibitory concentration (MIC) of different antibiotics by broth microdilution method (BMD) to suggest recommendations for Bacillus treatment.
    Materials and Methods: The study included 30 Bacillus species isolates recovered from normally sterile sites of the human body and were subjected to identification by MALDI-TOF, Vitek-2c, and HiCrome Bacillus Agar. BMD test was performed to determine the MIC of vancomycin, gentamicin, and ciprofloxacin.
    Results: Our study showed B. cereus was the most commonly isolated species (76.66%) followed by B. subtilis (23.33%). Regarding the different methods of identification, the highest agreement with MALDI-TOF was exhibited by HiCrome agar without polymyxin B (93.3%) followed by Vitek-2C and HiCrome agar with polymyxin with an agreement of 83.3%. Concerning the antibiogram, the tested isolates showed a susceptibility of 93.3%, 86.6%, and 83.3% towards vancomycin, gentamicin, and ciprofloxacin respectively.
    Conclusion: In conclusion, we spotlight that Bacillus species should no longer be considered contaminant bacteria in cultures, particularly in immunosuppressed patients. HiCrome Bacillus Agar without polymyxin B displayed the highest agreement with MALDI-TOF. Hence, it represents a good option for identification for routine laboratories where expensive instruments are unavailable. The high susceptibility towards the tested antibiotics can suggest the possibility of empirical use of vancomycin, gentamicin, and ciprofloxacin.

  • XML | PDF | downloads: 122 | views: 192 | pages: 495-502

    Background and Objectives: Helicobacter pylori, is a major etiologic agent associated with gastritis. There is more evidence of noncoding microRNAs (miRs) dysregulation in gastrointestinal diseases, including inflammation caused by Helicobacter pylori. Also, the classification of gastrointestinal malignancies using the miRs profile is better than the protein profile. MiRNA-155(miRNA-155) among other miRs plays an important role in control of inflammation and gastric malignancy, so it can be remarkable prognosis marker of gastric cancer in the phase of chronic gastritis. The aim of this study was to compare the expression of miRNA-155 in gastric biopsy and serum samples of adult patients with chronic gastritis.
    Materials and Methods: Biopsy and blood samples were collected from endoscopy candidates at Taleghani hospital, Tehran, during 2019. H. pylori infection was detected using histology, culture and molecular PCR methods. Based on cagA and vacA genotyping, the toxicity of H. pylori isolates were determined. After RNA extraction, the expression rate of miRNA-155 was evaluated by real-time polymerase chain reaction (RT-PCR) in gastric tissue and serum of adults infected by H. pylori (n = 30) compared with control group without infection (n = 20). RNU6 housekeeping miRNA were used as endogenous control and statistical analyses were performed using SPSS, ANOVA and Student’s t-test.
    Results: miRNA-155 expression in H. pylori infected adult patients increased significantly by 5.61 and 10.11 fold in serum and tissue respectively, compared to that observed in the control group. Evaluation of miRNA-155 expression pattern in relation to bacterial virulence factors showed that the increase in miRNA-155 expression is independent of CagA and VacA toxins.
    Conclusion: According to the differential expression patterns of miRNA-155 in serum samples of the infected adult patients, miRNA-155 has the potential to evaluate as chronic gastritis marker.

  • XML | PDF | downloads: 137 | views: 224 | pages: 503-509

    Background and Objectives: Cell-immobilization is used to maintain microbial culture to produce metabolites in repeated-batch or continuous fermentations, thereby reducing the time and resources spent on delivering mass production of microbe. The technique also enables shortening of the detoxification phase and the amount of formaldehyde required due to low incidence of viable bacteria in the extract.
    Materials and Methods: A solution of sodium alginate containing Clostridium perfringens cells was dropped into stirring CaCl2 solution via a sterile syringe needle. Optimizations resulted in reasonably uniform beads containing C. perfringens. Beads were externally stabilized by poly L-lysine, followed by immersion in a solution of Na-alginate to coat them with a new layer of alginate forming an alginate-PLL-alginate cortex.
    Results: This study proved successful in immobilizing C. perfringens cells inside uniform alginate microspheres. Cell loading and cell propagation inside the beads were measured. The cell loaded beads were cultivable in liquid media producing 550 minimum lethal doses per milliliter (MLD/ml) in a 72 h.
    Conclusion: The research paved the way for further investigations to optimize and establish an efficient bacterial encapsulation method. Thus, it seems possible to produce toxins from beads engulfing C. perfringens on larger scales via repeated-batch or continuous fermentation processes.

  • XML | PDF | downloads: 157 | views: 251 | pages: 510-517

    Background and Objectives: Acinetobacter baumannii is one of the main pathogens of the hospital and causes various infections. csu A/BABCDE involved in the initial surface attachment during biofilm formation and bap gene produces specific proteins at the cell surface that play a direct role in formation of biofilm and the infectivity of this bacterium. The aim of this study was to investigate the effect of silver nanoparticles and gold nanoparticles on the expression of bap and csu genes in the Acinetobacter baumannii biofilm formation.
    Materials and Methods: The susceptibility test was performed to determine the MIC of silver nanoparticles, gold nanoparticles and gold- vancomycin nanoparticles performed by broth dilution method on A. baumannii strains. The ability of biofilms formation in strains treated by MIC of silver nanoparticles and gold- vancomycin nanoparticles were evaluated by microtiter plate method and A. baumannii ATCC19606 used as control. Expression of the csu and bap genes were determinded by measuring the cognate mRNA level by real-time PCR.
    Results: In present study, gold nanoparticles could not prevent the growth and biofilm formation of A. baumannii strains. The MIC concentration of silver nanoparticles and vancomycin- gold nanoparticles were 6.25 μg/ml and 0.625 μg/ml respectively and MBC concenteration of nanoparticles for 70% of strain was 12.5 μg/ml and 1.25 μg/ml respectively. Real-time PCR and data analysis, determined that the expression of bap, csuC and csuE genes in A. baumannii strains treated with MIC concentration (6.25 μg/ml) of silver nanoparticles decreased compared to control groups. Also, the expression of csuC and csuE genes in strains treated with MIC concentration (0.625 μg/ml) of vancomycin -gold nanoparticles increased, however the expression of bap was decreased compared to the control groups.
    Conclusion: Due to the inhibitory effect of silver nanoparticles and gold- vancomycin nanoparticles against A. baumannii biofilm formation and genes expression, they can probably be used for prevent of biofilm formation in medical instrument or can be use for treatment of infections with or without antibiotic.

  • XML | PDF | downloads: 87 | views: 216 | pages: 518-528

    Background and Objectives: Nanoscience is one of the most important branches of modern science, which deals with the knowledge, structure, and properties of nanoparticles. This study aimed to investigate the ability of an airborne fungus (Aspergillus flavus) to synthesize silver nanoparticles (AgNPs) and to test the antibacterial activity of the synthesized AgNPs.
    Materials and Methods: The confirmation of AgNPs synthesis and the characterization of their properties were done using UV-Vis spectrophotometer, Zeta potential, Zeta sizer, FT-IR, and XRD analyses. The antibacterial activity was determined using broth microdilution method.
    Results: The findings showed that the average diameter of the resultant AgNPs was 474.2 nm with a PDI value of 0.27, and the zeta potential was -33.8 mV. Transmission electron microscopy (TEM) revealed that the AgNPs were regular and spherical in shape. TEM micrographs demonstrated that the AgNPs were smaller than those that were observed by DLS examination because the drying process resulted in particle shrinkage. The average size of AgNPs were less than 35 nm. The AgNPs exhibited a remarkable antibacterial activity against K. pneumoniae, E. coli, E. cloacae, S. aureus, S. epidermidis, and Shigella sp., and the MIC values ranged from 25 to 100 µg/mL. However, an exception was P. aeruginosa in which its MIC was >125 µg/mL.
    Conclusion: The results suggest that, the biosynthesized AgNPs by A. flavus could be utilized as a source of potent antibacterial agents in medicine and biotechnological applications.

  • XML | PDF | downloads: 95 | views: 168 | pages: 529-534

    Background and Objectives: The possible adverse effect of histamine on human health has made it a detrimental aspect to the quality and safety of many fermented food products especially fish sauce.
    Materials and Methods: In the present study, hdcA gene in Staphylococcus epidermidis TYH1 was knocked out and its effect on histamine production was evaluated. HdcA encodes histidine decarboxylase, an enzyme that produces histamine from histidine. Both strains of TYH1, the wild type (WT) and mutant (∆hdcA) were then incubated in tryptic soy broth (TSB) supplemented with histidine (0.5 mM). The histamine content determined by capillary zone electrophoretic (CZE) analysis. Safety assessment of this mutant of food origin was conferred by virulence genes.
    Results: It was found that S. epidermidis TYH1 exhibited production of histamine (50.09 ± 0.06 μg/mL), while ∆hdcA strain of TYH1 exhibited no histamine forming activity. Safety assessment of ∆hdcA revealed the presence of nuc gene, while superantigenic toxins and coa genes were not observed. Therefore, it has the ability to be used as a starter culture to decrease the histamine content in any fermented food products.
    Conclusion: Our study findings may contribute to provide a novel approach of promoting the food safety of fish sauce and other fermented food products regarding the regulation of histamine content.

  • XML | PDF | downloads: 133 | views: 163 | pages: 535-544

    Background and Objectives: Hadjr El Melh of Djelfa is an example of hypersaline ecosystems, which can harbor a wide variety of microorganisms under hostile physicochemical conditions. Given the importance of the study of halophilic microorganisms present there in terms of fundamental and applied microbiology, the purpose of this study was to characterize some halophilic archaea isolated from the brines of this environment.
    Materials and Methods: Eight water samples were chosen randomly and collected for physicochemical and microbiological analyses. Isolation of halophilic archaea was carried out by membrane filter technique. Ten strains were identified by polyphasic approach and tested for enzymes production.
    Results: Water samples of Djelfa’s rock salt were slightly acidic to neutral in pH (6.55-7.36) with salinity ranging from 258.68 g/l to 493.91 g/l. Phenotypic, biochemical, taxonomic and phylogenetic characteristics indicated that all strains were classified within the family of Halobacteiaceae. Based on the comparison of DNA sequences encoded 16S rRNA, it was determined that seven strains were affiliated to the genus Haloarcula, two strains were related to the genus Halobacterium and one strain within the genus Haloferax. Production of different enzymes such as protease, amylase, esterase, lipase, lecithinase, gelatinase and cellulase on solid medium indicated that one strain (S2-2) produced amylase, esterase, lecithinase and protease. However, no strains showed cellulolytic or lipolytic activity. Gelatinase was found in all tested strains.
    Conclusion: This report constitutes the first preliminary study of culturable halophilic archaea recovered from the brines of Djelfa’s rock salt with a promising enzymatic potential in various fields of biotechnology.

  • XML | PDF | downloads: 98 | views: 201 | pages: 545-553

    Background and Objectives: Neuraminidase inhibitors (NAIs) as an imperative antiviral for influenza prophylaxis and treatment are being consumed worldwide. Increasing use of these antivirals might be associated with drug resistance. Regarding the significance of these variations, this study aimed to investigate the mutations occurring in the NA gene of influenza A viruses leading to oseltamivir resistance during 2017-2019 in Iran.
    Materials and Methods: In this cross-sectional study, 40 influenza A (H1N1, H3N2) strains, isolated in National Influenza Center (NIC) from patients with Severe Acute Respiratory Infection (SARI) during 2017-2019 were subjected to RT-PCR and sequencing of NA complete gene. The frequency of oseltamivir resistance and variation of NA amino acids in these strains were investigated.
    Results: No significant mutation conferring oseltamivir resistance was detected. However, NA antigenic sites in these strains depicted minor changes compared to the vaccine strains. Among H3N2 isolates, mutations at 329, 344, 346 and 385 and among H1N1 isolates mutations at 143 and 188 residues occurred in NA antigenic regions.
    Conclusion: Evaluation of NA gene sequences, showed no resistant viruses to oseltamivir. Given that the viruses in the present study were the last viruses circulating in Iran before COVID-19 pandemic, the results will be beneficial to have a worthy comparison with the strains circulating after the pandemic. Constant monitoring for the emergence of drug-resistant variants and antigenic changes are crucial for all countries.

  • XML | PDF | downloads: 90 | views: 140 | pages: 554-562

    Background and Objectives: The viral transactivator HBx protein affect cellular, viral and pregenomic factors pathway. Mutations in this protein can produce new viruses with new antigenic determinants that are generally related to developing cancerous.
    Materials and Methods: In this cross-sectional study, 33 serum samples of patients diagnosed with acute HBV infection were investigated for HBeAg and HBV DNA viral load and HBx gene mutations. mutation in the HBx protein detected by sequencing analysis.
    Results: Out of the 33 samples, 19 samples were males (57.6%), and 14 samples were females. 15 (45.5%) were positive for HBx DNA and 18 patients were negative for HBx DNA (54.5%). After sequencing, three mutations were recognized in HBx at nucleotide positions 147, 148, and 391 that were stationed to G1524A, G1525A, and G1767C mutations.
    Conclusion: The analysis result of this study shows G1524A and G1525A mutations that an important role in altering the inhibition function of the HBx activity domain. The G1767C mutation inactivates HBx transactivation activity. These mutations have a critical role in the pathogenicity of the virus, and the intensity of hepatic tissue demolition and the development of cirrhosis or carcinoma in patients can be understood.

  • XML | PDF | downloads: 122 | views: 186 | pages: 563-567

    Background and Objectives: Hashimoto's thyroiditis is a chronic inflammation and an autoimmune disease of the thyroid gland that causes hypothyroidism. Genetic, internal, and environmental factors are the causes of this disease. Because human herpes viruses such as herpesvirus type 6 (HHV-6) are involved in some autoimmune disorders, they may also play a role in causing this disease. This study aimed to evaluate the association between human herpes virus 6 (HHV-6) with Hashimoto's thyroiditis.
    Materials and Methods: In the present study, 64 samples of thyroid paraffin tissue including 32 samples of thyroid paraffin tissue of healthy individuals as control, and 32 samples of thyroid paraffin tissue of Hashimoto's thyroiditis patients were taken from the pathology department of Loghman Hakim Hospital in Tehran. A questionnaire collected demographic information of patients. After DNA extraction from the samples, the nested-PCR technique was performed using specific primers for HHV-6.
    Results: Totally, the HHV6-DNA was found in 34.4% of thyroid tissues of healthy individuals (81.8% female and 18.2% male) and 46.9% of patients with Hashimoto's thyroiditis (73.3% female and 26.7% male). It was found that this difference in virus frequency between the two groups was not statistically significant (P value=0.309). There was also no statistically significant relationship between the prevalence of human herpesvirus type 6 and age or sex.
    Conclusion: Based on the present study, the number of HHV-6-infected individuals in Hashimoto's patients and controls did not differ significantly; therefore, HHV-6 appears not to be associated with Hashimoto's thyroiditis.

  • XML | PDF | downloads: 118 | views: 155 | pages: 568-573

    Background and Objectives: Parvovirus B19 (B19V) is usually transmitted through respiratory tract, but can also be received through blood transfusion. This study evaluated the seroprevalence, DNA existence, and circulating genotypes of B19V in hemophilia patients.
    Materials and Methods: Serum samples of cases and controls were analyzed for B19V using ELISA and real-time PCR. Finally, obtained sequences were used for genotyping.
    Results: Among cases, 3% were anti-B19V IgM positive and 47% were anti-B19V IgG positive and B19V DNA was detected in 16% of them. However, among controls, 38% were anti-B19V IgG positive (P>0.05) and 5% were B19V DNA positive (P= 0.019). Also ~13% of cases were positive and all of controls were negative for IgG avidity test (P= 0.029). Viral load in case group was higher than control group (P = 0.037).
    Conclusion: Since hemophilia patients receive large amounts of blood factors, prevalence of B19V in these patients might be higher than normal subjects.

  • XML | PDF | downloads: 169 | views: 390 | pages: 574-586

    Background and Objectives: Rapid diagnosis is a cornerstone for controlling and preventing viral disease outbreaks. The present study is aimed to develop a rapid field diagnostic test based on gold nanoparticles for the detection of lumpy skin diseases (LSD), and foot and mouth diseases (FMD) in animals with high sensitivity and specificity.
    Materials and Methods: FMD and LSD vaccines were used as a source of viruses' antigens for preparing monoclonal antibodies and conjugated with gold nanoparticles that characterized using various techniques such as UV-visible spectrometry, and transmission electron microscopy (TEM). Monoclonal antibodies (mAbs) for each serotype produced in experimental rats and used to capture antibodies for FMDV and /or LSDV. ELISA was used to screen 469 milk samples and 1165 serum samples from naturally infected cattle, buffaloes, sheep, and goats for validation of the lateral flow test (LFT). LSDV DNA was extracted from 117 blood and skin biopsy samples collected from naturally infected cattle during the 2019 outbreak.
    Results: The specificity and sensitivity of GNP-LFT were evaluated and compared to Ag-ELISA, Western blot tests (WB), and PCR. A total of 95 FMDV positives out of 469 (20.25%) milk samples and 268 FMDV positives out of 1165 (23.3%) serum samples from natural infected cattle, buffaloes, sheep, and goats examined by ELISA to valid GNPS-LFT Viral LSDV DNA was detected in 60/117 (51.5%) and 31/60 (52.9%). While the GNPS-LFT assay results were 49/117 (41.9%) and 29/60 (48.3%) blood and skin biopsy samples, respectively. The diagnostic sensitivity and specificity of the GNP-LFT test were 72% and 82%, respectively. All vesicular fluid and epithelium samples collected from infected animals were identified as positive by the GNP- LFT and Ag-ELISA. Ag-ELISA, on the other hand, was 90% and 100%. While the developed GNP-LFT used LSDV polyclonal antibodies were similar to ELISA and IgG-WB with a sensitivity of 72.8% and a specificity of 88.8%, respectively.
    Conclusion: The GNPS-LFT is a novel immunoassay based on mono or polyclonal antibodies conjugated with gold nanoparticles that provides an accurate, rapid, specific, and sensitive tool for field rapid diagnosis of FMDV and LSDV.

  • XML | PDF | downloads: 194 | views: 258 | pages: 587-597

    Background and Objectives: Monitoring of contagious diseases is important to advance our knowledge of their epidemiology and to enable more impressive investigation and prevention efforts. This study aimed to examine antifungal drug susceptibility and molecular analysis of clinical isolates of Trichophyton rubrum and Trichophyton mentagrophytes in humans and cattle.
    Materials and Methods: A total of 400 patients and 500 cattle were evaluated in this study. Dermatophytosis was confirmed in cases by direct microscopy and culture methods. Antifungal drug susceptibility profiles, MIC50, and MIC90 of isolates were determined using the broth microdilution method. Multiplex-PCR, RAPD PCR, and sequencing methods were used for the genetic analysis of virulence genes and the ITS1 and ITS2 regions, respectively.
    Results: A total of 175 patients and 120 cattle were diagnosed with dermatophytosis. Dermatophytes showed a remarkable rate (30%) of terbinafine resistance. T. mentagrophytes showed lower susceptibility than T. rubrum (MIC50=16 μg/mL). Strains harboring Mep1, Mep2, and Mep4 genes had the highest frequency among all genotypes. A RAPD-PCR dendrogram divided T. mentagrophytes and T. rubrum strains into three and six groups, respectively.
    Conclusion: A notable rate of resistance to terbinafine in isolated dermatophytes was reported in this study. Examination of RAPD-PCR results showed that T. rubrum strains had higher genetic diversity than T. mentagrophytes. Genetic monitoring of dermatophytes must be considered an important factor in providing fungal infection prevention and treatment approaches.

  • XML | PDF | downloads: 86 | views: 147 | pages: 598-605

    Background and Objectives: Esophageal candidiasis once thought to be restricted amongst immunocompromised patients is being increasingly reported among non-immunocompromised individuals. It is debilitating and if not treated well may cause chronic long-lasting infections. The objective of this study was to identify the various species of Candida causing esophageal candidiasis and analyse their antifungal susceptibility pattern.
    Materials and Methods: This was an observational, prospective study. Total of 108 patients who attended the Gastroenterology Department of Sir Thutob Namgyal Memorial Hospital, Govt of Sikkim, Gangtok, India between July 2012 – May 2018 were included in the study. They had complaints of upper gastrointestinal disturbances and chronic dyspeptic symptoms that required an endoscopy. Esophageal biopsy and brushings were taken and were transported to Microbiology Department. They were subjected to microscopic observation, fungal culture on Sabourauds dextrose agar. Preliminary species identification was done by chlamydospore formation and growth characteristics on CHROMagar Candida. Species confirmation and antifungal susceptibility testing was done on VITEK 2 system at Microbiology Department, Kasturba Medical College and Hospital, MAHE, Manipal, Karnataka, India.
    Results: A total of 108 patients were screened among which 73 samples were positive for Candida species and species identification and antifungal susceptibility was performed. Forty fiveisolates were found to be C. albicans, 8 were C. glabrata, 4 were C. tropicalis, 3 were C. lusitaniae 2 were C. krusei, 2 were C. lipolyticaand 1 was C. parapsilosis. Eight isolates could not be identified and were recorded as Candida spp. C. albicans isolates were predominantly sensitive strain with susceptibility of 95% for both amphotericin B and fluconazole and 100% for caspofungin. C. glabrata showed high resistance to fluconazole with one isolate showing intermediate resistance to caspofungin.
    Conclusion: Upper gastrointestinal symptoms even in non-immunocompromised patients need to be screened by endoscopy to rule out esophageal candidiasis. With the emergence of drug resistant non albicans Candida species diagnostic testing laboratories should include Candida species identification and antifungal susceptibility testing facility to provide effective patient care.

Short Communication

  • XML | PDF | downloads: 94 | views: 230 | pages: 606-610

    Background and Objectives: Blocking the attachment of diphtheria toxins to host cells through the intact receptor binding site (tox B) was the initial mechanism of action of the diphtheria vaccine. Diphtheria outbreaks in populations with good vaccination coverage can be caused by mutations or changes in the genetic structure of the tox B protein. The aim of this study was to characterize the Tox B protein produced by Corynebacterium diphtheriae isolated from 2018 to 2019 in patients in Jakarta who had already received the diphtheria vaccine.
    Materials and Methods: Of the 89 throat swab specimens of patients with a clinical diagnosis of diphtheria, 10 were positive for diphtheria and toxin. PCR was used to amplify the tox B DNA fragment in the 10 positive isolates. DNA sequencing was conducted with overlapping primers and the DNA sequences were analysed by using SeqScape V2.7.
    Results: Of the 10 isolates, nine isolate showed a DNA mutation (G30A), but the mutation did not change the amino acid encoding arginin (silent mutation). Our findings indicate that the efficacy of the diphtheria vaccine used in Indonesia has not decreased because of mutations in the tox B genes not change the amino acid.
    Conclusion: Overall, there are no amino acid changes in the tox B protein, indicating that the outbreaks are not affected by mutation in tox B. Another possible mechanism – overexpression of the toxin – is likely responsible for causing diphtheria in patients who have a complete history of immunization in Indonesia.