Avicenna Journal of Clinical Microbiology and Infection
Volume:8 Issue: 2, Jun 2021

Brucellosis is a common zoonotic disease with protean clinical manifestations. Osteoarticular involvement is the most common complication of the disease. This study aimed to compare the clinical and para-clinical manifestations of brucellosis among the patients with and without spondylodiscitis.

In this comparative and cross-sectional study, 135 patients having brucellosis with and without spondylodiscitis and admitted to Sina hospital in Hamadan, Iran from March 2009 to March 2014 were included. Clinical and para-clinical data of the patients were obtained from their medical records in the hospital based on a designed checklist.

Thirty-five patients having brucellar spondylodiscitis (BS) with the mean age of 55.60 ± 14.31 years, and 100 patients having brucellosis without BS with the mean age of 43.27 ± 18.35 years were examined. A significant difference was found between the mean age of the patients with spondylodiscitis and that of those without spondylodiscitis (P < 0.001). All patients with spondylodiscitis complained of back pain and vertebral tenderness, while 60% of the patients without BS suffered from back pain but experienced no vertebral tenderness (P = 0.003). The most common vertebral involvement in spinal MRI of the patients with BS was L4-L5 (45.7%). Patients with spondylodiscitis had more increased ESR and CRP than those without spondylodiscitis (P < 0.001).

It is recommended that Brucellar spondylodiscitis be considered in the differential diagnosis of the patients with prolonged fever, back pain, and vertebrae tenderness in the endemic areas.

Bacteriocins are heterogeneous inhibitory substances that could affect the bacteria belonging to the same genus. Both gram-positive and gram-negative bacteria produce bacteriocins. One of the best sources of producing bacteriocins is Lactobacillus. The aim of this study was to isolate and purify bacteriocin from Lactobacillus rhamnosus and assess its effects on Pseudomonas aeruginosa and synthesis of its lipopolysaccharide.

L. rhamnosus was prepared and cultured at MRS broth and incubated at 37ºC for 24 hours. Then, the medium was centrifuged for the isolation of bacteriocin and the supernatant was considered as bacteriocin. Antibacterial properties of different concentrations of bacteriocin (50, 100, 200, and 400 μg/mL) against P. aeruginosa were assayed by using agar diffusion and broth micro dilution methods. Also, the effect of bacteriocin against lipopolysaccharide synthesis in P. aeruginosa was analyzed by using one unit of minimum inhibitory concentration (MIC) for bacteriocin.

The results showed that all bacteriocin concentrations had antibacterial activity against P. aeruginosa. The MIC value was 31.25 μg/mL and minimal bactericidal concentration (MBC) was 62.5 μg/mL. Also, the synthesis of lipopolysaccharide decreased during P. aeruginosa growth period, and it reached zero after 5 hours.

The results of this study showed the antibacterial effect of bacteriocin isolated from L. rhamnosus against P. aeruginosa. In addition, this bacteriocin prevented the lipopolysaccharide synthesis in P. aeruginosa.

Metal oxide nanoparticles (NPs) have shown promising efficacy for combating bacterial resistance due to their antibacterial properties. This research investigated the effect of zinc oxide NPs (ZnO-NPs) on the antibacterial activity of conventional antibiotics including ciprofloxacin (CIP), cefotaxime (CTX), and colistin (CST) against multidrug-resistant Acinetobacter isolates.

The disc diffusion method was performed to detect the pattern of antibiotic resistance in isolates. The synthesized ZnO-NPs via the solvothermal method were characterized by field emission scanning electron microscopy (FESEM), X-ray diffraction (XRD), and energy-dispersive X-ray spectroscopy (EDS). Finally, the broth microdilution technique was conducted to demonstrate the antibacterial activity of CIP, CTX, and CST antibiotics with and without a sub-inhibitory concentration of ZnO-NPs.

XRD, EDS, and FESEM results confirmed the crystalline structure of ZnO-NPs, and the average size was 100±58.68 nm. All isolates were discovered to be of multidrug-resistant (MDR) type and fully susceptible to CST. The antibacterial activity of CTX and CIP was restored when combined with a sub-inhibitory level of ZnO-NPs (0.25 mg/L), and the highest activity was obtained at the concentrations of 32 μg/mL CTX and 8 μg/ mL CIP. Eventually, ZnO-NPs showed a synergistic effect on the antibacterial properties of CST against MDR Acinetobacter.

This research indicated that the combination of ZnO-NPs with some common antibiotics can be considered as a novel strategy for reducing the spread of antibiotic-resistant bacteria.

Of all enterococci species, the most renowned clinically as multidrug-resistant pathogens are Enterococcus faecium and Enterococcus faecalis. Vancomycin-resistant Enterococcus (VRE) species are the principal cause of opportunistic hospital-acquired infections, due to numerous resistance mechanisms.

In this study, the prevalence and antibiotic resistance profiles of VRE according to clinical sources from three selected hospitals in Southwest-Nigeria were investigated. Altogether, 431 samples (urine, rectal, and wound swabs - caesarian section (CS), automobile accidents, and other skin lesions and abrasions) were collected from three selected hospitals in Osun State, Nigeria. Established techniques were employed for the recovery of enterococci and screening for VRE while antibiotic susceptibility tests were carried out by disc diffusion technique.

Altogether, 208 (48.3%) enterococci strains were recovered from which 85 (40.9%) were VRE. E. faecium predominated at 71.8% (61/85) and E. faecalis at 28.2% (24/85) as determined by phenotypic characterization. VRE isolates exhibited 100%, 97.6%, and 92.9% resistance to ampicillin, clindamycin, and quinupristin-dalfopristin (Q/D) respectively. The least resistance in-vitro was to tigecycline (27.1%). None of the antibiotics exhibited 100% activity against all the isolates. vanA resistant phenotype was prevalent at 65.9%. E. faecium from all study locations displayed higher levels of resistance than E. faecalis. Multiple antibiotic resistance (MAR) indices in all VRE isolates were ≥0.2, all being multidrug-resistant.

The high prevalence rate along with the high level of multidrug resistance observed in the present study is worrisome and poses a continuous threat in the therapy of illnesses triggered by VRE as vancomycin was perceived as a drug of choice to curb enterococcal infections.

Rhinoviruses (RVs) represent the most important aetiological agents of the common cold and are responsible for about two-thirds of acute exacerbations of chronic bronchitis, asthma, and chronic obstructive pulmonary disease (COPD) in both children and adults. This study aimed to design a pan-serotypic vaccine capable of inducing cross-reactive antibodies against most of the RV by using a reverse Vaccinology approach.

Bioinformatics analysis was carried out to characterise the capsid proteins (VP1, VP2, VP3, and VP4) of all known RV serotypes and to predict potential immune motifs. Conserved motifs consisting at least nine- mers common across all RV-A or B serotypes were selected and synthesized chemically. Four tagged full-length genes coding the capsid proteins of an ideal strain (HRV-74), VP1, VP2, VP3, and VP4 were constructed and cloned in vitro. Upon expression , the purified recombinant proteins were also administered subcutaneously to other groups of rabbits. The responses and cross-reactivity of the specific immunoglobulin M (IgM) and G (IgG) to the peptides, proteins, and whole viruses were measured.

The obtained anti-peptide antibodies exhibited a cross-neutralizing activity for different RV strains in vitro. Antibodies raised to the synthetic peptides exhibited cross-reactivity against the corresponding recombinant proteins and antigenically distinct RV strains coated on plates via ELISA assay.

The study findings indicated that the peptides corresponding to the conserved region of the RV capsid proteins were potent immunogenic; moreover, the findings showed that their combination was crucial for extending the cross-protection against variant RVs.

Scrub typhus is an infectious disease with potentially fatal consequences. It is caused by Orientia tsutsugamushi and transmitted to humans via the bites of infected larval mites (chiggers). Scrub typhus is one of the most neglected and severe diseases despite its easy treatment. Delay in diagnosis and treatment is not uncommon, resulting in a 10% fatality rate in cases of inappropriate treatment. The main aim of this study was to determine the prevalence of scrub typhus in Southeast Asia and the risk factors contributing to the disease in order to aid the development of effective control and prevention strategies.

In this meta-analysis, the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) were used as a guideline. The systematic literature search was performed for the relevant titles, abstracts, and keywords in the journal databases of PubMed, EBSCOhost, Ovid, and Google Scholar in November 2018. The keywords and terms were derived from population, intervention, comparison, outcome analysis, and a total of 720 studies were retrieved accordingly. Only original research, published articles, and articles written in the English language were selected for this purpose. Screening of abstracts had shortlisted 36 studies and data extraction was conducted accordingly. However, only 9 studies were accepted after a review of the full texts. The other 27 articles were excluded due to ecological studies and different outcome measures.

Several factors in this meta-analysis were identified to have significant risk of having scrub typhus (P < 0.05), including people who are involved in the agriculture sector (OR: 2.90, 95% CI: 2.33, 3.77), those having direct contact or being exposed to the vector habitat (OR: 2.17, 95% CI: 1.49, 3.16), and house yard conditions (OR: 3.02, 95% CI: 2.1, 4.33). Other factors were indoor house conditions (OR: 1.96, 95% CI: 1.45, 2.67), those having close contact with rodents or domestic animals (OR: 2.51, 95% CI: 1.67, 3.77), those working in paddy fields or vegetable farms (OR: 5.17, 95% CI: 3.15, 8.47), and bad occupational safety practices (OR: 1.71, 95% CI: 1.12, 2.62).

The identified risk factors from this meta-analysis highlight the importance of public health intervention strategies for the prevention of scrub typhus among high-risk populations.