Jundishapur Journal of Microbiology
Volume:16 Issue: 8, Aug 2023

Despite the global vaccination program, there are many new cases of pertussis in different societies annually.

This study aimed to investigate the prevalence of some microorganisms associated with pertussis-like syndrome and compare the clinical presentations between Bordetella pertussis and pertussis-like syndrome in children.

Children younger than 5 years old suspected of pertussis-like syndrome were admitted to a hospital in Ahvaz, Iran, and examined from July 2018 to July 2019. Nasopharyngeal samples were evaluated using molecular methods. The studied microorganisms were the following: Bordetella pertussis, B. parapertussis, Mycoplasma pneumoniae, Chlamydophila pneumoniae, adenovirus, respiratory syncytial virus, and parainfluenza virus type III.

Forty-five children were enrolled. Bordetella pertussis was detected in 15 cases (33.3%), respiratory syncytial virus in 14 (31.1%), C. pneumoniae in 3 (6.7%), and parainfluenza virus type III in 3 (6.7%). The collected samples were negative in terms of M. pneumoniae, adenovirus, and B. parapertussis. In the case of paroxysmal cough, the clinical symptoms were significantly different between pertussis and pertussis-like groups.

The results indicated that children with pertussis-like syndrome are commonly infected with B. pertussis and respiratory syncytial virus, so more attention should be paid to this issue. The study also demonstrated the importance of molecular diagnosis methods, along with diagnosis based on clinical symptoms, in children suspected of pertussis-like syndrome.

COVID-19 might worsen preexisting cardiac conditions and cause new heart failure (HF). To appropriately triage and treat patients, an early diagnosis is necessary.

This study assessed the levels of antibodies immunoglobulin G (IgG) and immunoglobulin M (IgM) required for the coronavirus spike S protein in the serum of individuals with cardiovascular disease (CVD) who developed HF complications from COVID-19.

A total of 104 hospitalized patients with confirmed COVID-19 were equally divided into severe COVID-19 cases with new HF evidence and controls. The levels of IgG and IgM antibodies vs SARS-CoV-2 were measured. The possible correlation of antibody levels with underlying cardiac risk factors was also investigated.

It was found that 86% of HF patients and 5% of controls had an IgG level greater than 100 AU/mL (P < 0.05). Ischemic heart disease (IHD) was the most common disease in the patient group, and the highest level of antibodies was also found in this group.

Increasing IgG during COVID-19 can beoneof the signs of worsening heart disease, which ismoreprevalent in patients with an underlying IHD and hypertension.

The spike protein of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has been undergoing variation. Most of the variants cause no concern for human health. Some others have had worse outcomes in terms of transmissibility, vaccination resistance, and, generally, the survival of patients infected with SARS-CoV-2.

This study investigated the mutation of interest in the receptor-binding domain (RBD) of SARS-CoV-2.

Ribonucleic acid (RNA) was extracted from 40 swap samples. Next, the polymerase chain reaction (PCR) assay was carried out to detect the RBD. Investigation of SARS-COV-2 RBD was performed completely by phylogenetic and tree alignment. The multiple sequence alignment (MSA) of the biological sequence of RBD was created by BioEdit, Snap Gene, and MEGA software and was then compared to sequences of different variants of SARS-COV-2 in the GenBank (National Center for Biotechnology Information). The Influenza Surveillance and Response System (GSAID) was used to detect mutations in the RBD sequence.

Multiple sequence alignment (MSA) RBD domain showed that the RBD domain sequence obtained from the Iranian patients’ highest identity by severe acute respiratory syndrome coronavirus 2 isolate MZ907347. Several mutations of interest, including A475V, L452R, V483A, and F490L, were detected in the RBD region. However, the dN/dS analysis detected positive selection in RBD regions.

Amino acid changes in the surface protein can significantly alter the viral function and/or interactions with neutralizing antibodies. Most of the nucleotide changes in the spike gene reduce infectivity. TheV503Wand P521Q mutations reduce infectivity, the A522Q mutation increases sensitivity to neutralizing antibodies, and the H519T mutation decreases susceptibility to convalescent sera.

Antibacterial peptides have a broad antibacterial spectrum and are not affected by classical resistance mechanisms; therefore, they can be used in combination with classic antibiotics to treat multidrug-resistant Acinetobacter baumannii infections, making them an alternative for the development of new therapeutic strategies.

This study aimed to assess the effectiveness of combining amphiphilic peptides, specifically C12-prp and mastoparan, with antibiotics in combating A. baumannii clinical isolates.

We investigated combinations that inhibited the growth of A. baumannii clinical isolates, consisting of 24 extensively drug-resistant (XDR) and 11 pan-drug-resistant (PDR) strains collected between January 2004 and December 2014 at Chosun University Hospital using a multiple combination bactericidal test (MCBT). A time-kill study was used to confirm the bactericidal activity and synergism of the four combinations selected via MCBT.

Four combinations (C12-prp-colistin, C12-prp-rifampicin, mastoparan-colistin, and mastoparan-rifampicin) showed 100% (24/24) synergy with XDR A. baumannii strains. However, in the case of the PDR strains, only two combinations, C12-prp-colistin and mastoparan-colistin, showed a 9.1% (1/11) synergy. Moreover, the mastoparan-colistin and mastoparan-rifampicin combinations showed 100% (24/24) bactericidal activity against the XDR A. baumannii strains, whereas the C12-prp-colistin and C12-prp-rifampicin combinations showed 91.7% (22/24) bactericidal activity. None of the combinations showed bactericidal activity against PDR strains.

Our study highlighted the substantial synergistic antibacterial efficacy of C12-prp and mastoparan peptides when combined with colistin or rifampicin. Furthermore, this approach could be a promising alternative for developing new treatment strategies for XDR A. baumannii infections.

Klebsiella pneumoniae is a bacterium that commonly causes urinary tract infections (UTIs) in hospital settings. The widespread and improper usage of quinolones has increased the resistance rates against these broad-spectrum antibiotics.

This study aimed to examine the connection between the ability to form biofilms and fluoroquinolone resistance in K. pneumoniae isolated from catheter-associated UTIs.

A total of 110 nonduplicative K. pneumoniae-related catheter-associated UTIs were isolated from three large educational hospitals in Babol, north of Iran. The minimal inhibitory concentration (MIC) of ciprofloxacin was calculated for each detected isolate using the agar dilution procedure. Biofilm production was investigated by a 96-well flat-bottom microtiter plate. The prevalence of gyrA, parC, qnrA, qnrS, acc (6’)-Ib-cr, qepA, qnrB, oqxA, and oqxB genes was evaluated using polymerase chain reaction (PCR).

Overall, 28.2% of the strains were resistant to imipenem and considered carbapenem-resistant K. pneumoniae (CRKp). Ciprofloxacin resistance was observed in 66.4%. Moreover, 70% of the isolates produced biofilm. Biofilm production was significantly higher in ciprofloxacin-resistant compared to ciprofloxacin-susceptible strains (P-value < 0.05). Molecular distribution of resistance genes in the 68-fluoroquinolone resistance-Kp strains showed that the prevalence of gyrA, parC, qnrA, qnrS, acc (6’)-Ib-cr, qepA„ qnrB, oqxA, and oqxB genes was 39.7%, 42.6%, 5.9%, 54.4%, 69.1%, 94.1%, 41.2%, 69.1%, and 83.8%, respectively.

Our study highlights the high prevalence of plasmid-mediated quinolone resistance genes in clinical samples of K. pneumoniae in the studied region, which is alarming given the possibility of the spread of these pathogens and the few treatments available for infections brought on by multidrug-resistant strains. Moreover, the study characterizes particular mutations in the parC and gyrA genes that cause quinolone resistance.

Onychomycosis is one of the most common fungal infections. The most common etiological agents of onychomycosis in Iran are Candida species, especially fingernails. It is more common in women than men, particularly workers in occupations requiring them to submerge their hands or feet in water for prolonged periods.

The current study’s main aim was to determine the abundance of candidal onychomycosis, identify the Candida species using molecular methods, and evaluate the in vitro antifungal susceptibility profiles.

One hundred forty samples were obtained from patients suspected of onychomycosis, and 51 (36.4%) Candida strains were identified by PCR-RFLP. The in vitro susceptibility of four triazole (FLC, ITC, VRC, and POS) antifungal drug testing of 51 Candida species was performed using broth microdilution.

Direct microscopic examination by KOH 20% of 140 nail samples showed that 51 (36.4%) samples were positive in terms of fungal elements, with Candida parapsilosis complex being the most frequently isolated of patients, followed by C. albicans complex, C. glabrata, C. krusei, C. tropicalis, C. guilliermondii, C. famata, C. kefyr, and Candida species. All Candida species showed they were susceptible to four triazoles, except that five C. kruseiwereresistant to fluconazole. OnlyoneC. glabrata isolatesandoneC. parapsilosis isolate were resistant to fluconazole.

The growing trend towards the frequency of fingernail onychomycosis in housewives has been noticeable in the last decades in Iran. Therefore, accurate identification of Candida species and perform in vitro antifungal susceptibility testing can aid physicians in choosing an effective potential drug for treating onychomycosis patients.