Avicenna Journal of Clinical Microbiology and Infection
Volume:7 Issue: 3, Sep 2020

Peptidoglycan (Murein), which consists of disaccharide and amino acid chain subunits, has a key role in bacterial survival and ranks first in the line defense system against drug therapy. In addition, the transpeptidase enzyme plays an important role in cross-linking in bacterial cell walls. In Escherichia coli bacteria, cross-linking happens by proteins that have a D-D transpeptidase role and bond two amino acids of D-alanine together. These proteins are characterized by their affinity for and binding of penicillin thus they are called penicillin-binding proteins (PBPs). It should be noted that this bonding formation is prevented by the beta-lactam family as they have a similar structure to the above-mentioned proteins. The product of the idtD gene by characteristics such as L-D transpeptidase can catalyze the peptidoglycan structure in the bacterial cell wall in the presence of beta-lactam antibiotics.

In this study, around 426 interactions were identified between genes and approximately 20 genes with a key role in the process of bacterial cell wall synthesis by the reconstruction of 44 genes involved in bacterial cell wall synthesis.

The idtD gene locus at the reconstructed network clearly shows that its catalytic activity is the side activity, and there won’t be a lag or disturbance in the procedure cell wall synthesis by removing it from the cycle. However, this side process causes the strengthening of the bacterial cell wall synthesis process against disorders arising by the presence of beta-lactam antibiotics.

These five genes in E. coli that furnish L-D transpeptidase properties include IdtA, IdtC, IdtD, IdtE, and mrdA out of which, IdtD is the most important gene in this process

Hepatitis C virus (HCV) is a public health issue. Successful treatment of HCV infection results in sustained virologic response (SVR) in the majority of subjects. Subsequent recurrence of HCV, either from late relapse or reinfection, may occur. The aim of this study was to assess the recurrence rate of HCV in Iraqi patients.

In this study, 113 patients who completed anti-HCV therapy successfully were recruited. While 23 patients received a classical regimen of peg-interferon plus ribavirin, 90 patients received direct-acting antiviral therapy. Those patients were followed up for three years. HCV recurrence rate was calculated using events/ person years of follow-up (PYFU).

Among the recruited patients, HCV RT-PCR was positive in 1 (0.88%) patient giving a recurrence rate of 2.95 per 1000 PYFU. When the data were stratified according to the treatment regimen, the recurrence rate was 14.49 per 1000 PYFU in patients who received the classical regimen of interferon and ribavirin.

The overall recurrence rate was low in Iraq. No recurrence was recorded in patients received direct-acting antiviral therapy. Further studies are needed with a larger sample size and longer follow-up to determine the relapse rate in Iraq.

Arcobacter is one of the most common bacteria in humans and livestock, leading to gastroenteritis in humans as well as genital and enteric diseases in animals. This bacterium is known to be the main cause of diarrhea. In molecular studies, the 16SrRNA gene was primarily used as the standard gene for the determination of the Arcobacter. The purpose of this study was to investigate the molecular detection of Arcobacter using glyA, atpA, and gyrA genes compared to16SrRNA.

In this study, 61 samples of Arcobacter DNA isolated from fecal specimens of patients and healthy individuals in the sample bank were used. In order to detect Arcobacter, the intended primers for 16SrRNA as well as glyA, atpA, and gyrA genes were used for polymerase chain reaction (PCR). The products obtained from the PCR were sequenced.

The results of the proliferation reactions indicated the accuracy of the intended primers and the associated molecular experiments. Our results showed that 65.57% of the cases were detected to be positive for Arcobacter among 61 samples using the glyA gene. This percentage was higher compared to 16SrRNA (42.62%), gyrA (42.62%), and atpA (24.59%). The analysis was statistically significant.

Given the presence of repetitive sequences in the 16SrRNA in most bacteria, the interpretation of the results is likely to be difficult for researchers. The results of this study showed more sensitivity and accurate diagnosis of Arcobacter using the glyA gene than other studied genes. In diagnostic studies of Arcobacter, the glyA gene is proposed as an alternative to the 16SrRNA.

Helicobacter pylori infection is associated with peptic ulcer diseases and gastric adenocarcinoma. Accordingly, the aim of this study was to assess the efficiency of tetracycline quadruple therapy versus levofloxacin-based regimen (LBR) for the eradication of H. pylori.

To this end, 197 subjects with H. pylori infection were recruited in this randomized clinical study in Kurdistan region, Iraq between October 2018 and May 2019 and randomly divided into 2 groups. The LBR group received levofloxacin 500 mg one time per day, amoxicillin 1000 mg two times per day, and omeprazole 20 mg two times per day for two weeks. In addition, the tetracycline-metronidazole-bismuth (TMB) group received bismuth subcitrate 140 mg, metronidazole 125 mg, and tetracycline 125 mg plus omeprazole 20 mg twice per day for 10 days. Finally, 28 days after the completion of the treatment course, the eradication of H. pylori was evaluated by the 14C urease breath test.

The total eradication rate of H. pylori infection was 149/197 (75.6%). Although the success eradication rate in the LBR regimen was 70/112 (62.5%), the eradication success rate was 79/85 (92.9%) in the TMB regimen (P = 0.001, odds ratio = 7.9, confidence interval = 3.17-19.7). Finally, gender and age represented on the effect of the eradication rate.

In general, the bismuth-based regimen could eradicate a high rate of H. pylori infection. Therefore, this regimen can be used to overcome treatment failure in areas with a high prevalence of antibiotics resistance.

Influenza is a main viral disease in poultry production that causes various annual economic losses to the poultry production industry. Avian influenza virus (AIV) is susceptible to antigenic changes, and the genome of this virus codes different proteins some of which have more biological properties. The matrix (M) protein is one of these proteins that plays a role in the immunization and pathogenesis of the virus. Therefore, the evaluation of molecular characteristics and changes in the influenza gene can provide a new horizon for further genomic studies. Accordingly, in this study, the molecular characteristics of AI H9N2 strains were compared with those of other reference strains in the world gene bank by determining their M gene sequence.

In this regard, 4 strains of AIV (H9N2) were selected for the analysis of the M gene sequence. The polymerase chain reaction product was sequenced after its purification from the gel and the amplification of the M gene. Finally, the nucleotide sequence of these strains and other reference strains were aligned and analyzed by MegAlign software using the Clustal W method.

The results indicated that the M gene sequences of AIVs belonging to the last decade were highly similar to each other and other reference strains in special regions such as the ionic gate and the cleavage site. Based on the M sequence, 3 strains appeared to be resistant to amantadine. These viruses in the epitope regions showed a high similarity to the highly pathogenic avian influenza (HPAI) Hong Kong H5N1 strain.

In general, it seems that the sequence of the M gene in Iranian H9N2 strains belonging to the last decade is relatively constant although the continuous monitoring of changes in various genes of the influenza virus is necessary

The resistance of pathogenic bacteria against synthetic drugs led scientists to conduct research on medicinal plants. The present study investigated the antioxidant and antibacterial activity of the aqueous, methanol, and ethanol alcoholic extracts of the plant Citrus maxima Merr. (Syn. Citrus grandis) against some human pathogenic bacteria. Then, the presence of secondary metabolites was evaluated in vitro, including alkaloid, saponin, and tannin.

The samples (i.e., root, stem, and seed) of C. maxima were collected at Babolsar, Mazandaran province, Iran. The agar well diffusion assay was used to determine antibacterial activity. In addition, several bacteria were applied based on the aim of the study, including Streptococcus pyogenes (PTCC1447), Bacillus subtilis (PTCC-1156), Bacillus cereus (PTCC-1247), Enterococcus faecalis (PTCC-1185), Micrococcus luteus (ATCC-10987), and Staphylococcus aureus (PTCC-1189). Further, some Gramnegative bacteria were used, encompassing Escherichia coli (ATCC-25922), Shigella boydi(-), Salmonella typhi (PTCC-1609), Pseudomonas aeruginosa (PTCC-1181), Enterobacter aerogenes (PTCC-1221), and Klebsiella pneumoniae (PTCC-1139). Next, the minimum inhibitory and bactericidal concentrations were determined by the serial dilution method. Furthermore, free radical activity was identified by 2,2-diphenyl-1-picrylhydrazyl. Moreover, the total phenolic and total flavonoid contents were conducted by Folin-Ciocalteu and aluminum chloride methods, respectively. Finally, the phytochemical compounds were investigated as well.

The highest sensitivity was observed on M. luteus against the root methanol extract. Additionally, the total phenolic content of root, seed, and leaf was determined as 98.22, 89.66, and 77.51 (mgGA/g), respectively. Similarly, the flavonoid content was determined as 3.52, 3.43, and 3.56 (mgQ/g), respectively. In addition, the IC50 of the root, seed, leaf, and ascorbic acid were calculated as 0.129, 0.135, 0.113, and 0.109 mg mL-1, respectively. Eventually, the methanol extract of the leaf and root showed the presence of alkaloid, saponin, and tannin.

In general, C. maxima is suggested for producing natural drugs with antibiotic properties in the pharmaceutical industry due to the presence of secondary metabolites in its different parts.