Antibacterial Activity and Toxicity of Zinc Oxide Nanoparticles Combined with Supernatants of Lactobacillus spp. Against ESKAPE Bacteria: A Novel Mixture.

Background: The emergence of multidrug resistance among nosocomial pathogens has prompted researchers to look for new antibacterial sources. Metal nanoparticles and probiotic products have attracted the attention of researchers. However, combination therapy is an attractive alternative in this field. Objectives: This study evaluated the antibacterial activity and toxicity of Zinc Oxide nanoparticles (ZnO-NPs) combined with cell-free supernatant (CFS) of Lactobacillus plantarum and Lactobacillus acidophilus alone and in a novel mixture. Methods: Antibacterial effects and cytotoxic properties of ZnO-NPs, CFS of L. plantarum (SLP), and CFS of L. acidophilus (SLA) were determined alone and in a mixture against ESKAPE strains. In addition, the viability percentage of the cells was evaluated after exposure to these agents. Results: Antibacterial mixtures (ZnO-NPs with SLP or ZnO-NPs with SLA) demonstrated synergistic and additive effects against Pseudomonas aeruginosa (FIC≤0.75), Acinetobacter baumannii (FIC = 1), and Escherichia coli (FIC≤0.75). The viability percentage of the cells after 24 h of exposure to a mixture of ZnO-NPs and SLA (about 50%) was more than when the cells were exposed to ZnO-NPs alone (about 30%) at the same concentration. Conclusions: A mixture of ZnO-NPs and CFS of probiotics can be an alternative to antibiotics, with more effectiveness and fewer side effects.

Topical Treatment of Second-Degree Burn Wounds with Lactobacillus plantarum Supernatant: Phase I Trial.

Background & Objective: A burn wound is sterile immediately after injury, but opportunistic bacteria colonize the wound within 48 to 72 hours after the burn, causing delayed or failed burn wound healing. In addition, the presence of multidrug-resistant (MDR) pathogens doubles the treatment problems. Lactobacillus plantarum (L. plantarum) is a well-known antibacterial and healing agent that could be used topically to treat burn wounds. Case Series Presentation: This clinical trial study (Case Series) was performed on 20 patients with deep second-degree burns. Patients had bilateral wounds; the wound on one side of the body was considered as control (treated with silver sulfadiazine) and the other side of the body as treatment (treated with bacteria-free supernatants (BFS) of L. plantarum). The wounds were evaluated by microbial assessments and assessments related to healing. Pseudomonas aeruginosa, Klebsiella pneumonia, and Staphylococcus aureus were isolated from 4 (22.2%), 0%, and 2 (11.1%) of wounds treated with L. plantarum on the fifth day of the treatment, respectively. Furthermore, 12 (66.7%) of wounds treated with L. plantarum were free from bacteria. The need for skin grafting was the same in both treatment and control groups, but graft rejection in the group treated with L. plantarum was (0%) (P=0.02). Conclusion: Regarding eliminating or reducing infection and wound healing, bacteria-free supernatants of L. plantarum can be considered a possible topical treatment option in the case of second-degree burn wounds.

Investigating the relationship between extended spectrum ß-lactamase producing Escherichia coli in the environment and food chains with the presence of this infection in people suspected of septicemia: Using the fuzzy set qualitative comparative analysis.

PROPOSE: Among antibiotic resistance cases, resistance to ß-lactam antibiotics is a major concern for the treatment of microbial infections. Furthermore, the prevalence of extended-spectrum ß-lactamases (ESBL) Escherichia coli (E. coli) in environment, food, and human resources of Iran has increased over the past few years. This study aimed to predict the relationship between the prevalence of ESBL E. coli in the environment and the food chains with the presence of this infection in people suspected of septicemia using fuzzy set qualitative comparative analysis model. METHODS: In this analytical cross sectional study samples were collected from the environment (hospital sewage, downstream and upstream urban sewage, and slaughterhouse sewage), food (chicken), and human chains (people suspected of septicemia) in Tehran province, Iran. This study was conducted from September to February 2019 and the prevalence of ESBL E. coli was calculated in each resource. Then, the relationship between the prevalence of ESBL E. coli in the environment and food chains and its prevalence in the human chain was predicted using the fuzzy set qualitative comparative analysis. RESULTS: The results showed the prevalence of ESBL E. coli in those suspected of septicemia in September, October, November, December, January and February was 58.1%, 60%, 33.3%, 100%, 43%, and 57.8%, respectively. Also, the results of the fuzzy set qualitative comparative analysis indicated hospital wastewater and chicken contamination with ESBL E. coli were the main causes of contamination with ESBL E. coli in people suspected of septicemia. CONCLUSIONS: According to the results of this study, if there is a contamination of hospital wastewater and chickens in an area, it can be claimed that people suspected of septicemia are infected with ESBL E. coli, and the percentage of this contamination can be high. On the other hand, controlling ESBL E. coli in hospital wastewater (environmental chain) and chickens (food chain) can prevent contamination in people with suspected septicemia.

Comparison of the effects of Lactobacillus plantarum versus imipenem on infected burn wound healing.

Background: Infection of burn wounds is one of the most important problems in the world. Lactobacillus plantarum is known for burn wound healing because of the immunomodulatory and anti-microbial roles. This study was performed to compare the effects of L. plantarum and imipenem - alone and in combination - on infected burn wound healing. Methods: Burn wounds were experimentally induced on 50 rats in three test groups (germ and supernatant of L. plantarum ) and two control groups (n=10 each) and were inoculated with Pseudomonas aeruginosa. During a 14-day period, wounds in all groups were daily treated topically. The data were analyzed using one-way analysis of variance followed by Tukey-Kramer and LSD. A p-value of < 0.05 was considered as statistically significant. Results: The mean size of the wound on day 14 after the treatment in the probiotic group was significantly lower than the control and the supernatant treated groups (p<0.05). The percentage of wound healing was significantly higher in the probiotic pellet treated group compared to the imipenem and the supernatant groups (by Anova test: 69.58%, p=0.022). The mean leukocyte count in the probiotic pellet group (12110) and supernatant group (13650) was significantly higher than the imipenem group (7670) (p=0.002 and 0.001, respectively). Wound cultures revealed that the percentage of cases where the pathogens had no growth was significantly different among the comparison groups. In all three test groups, P. aeruginosa was completely eliminated in comparison to the positive control group (p<0.05). Conclusion: The results of our study showed that L. plantarum and its by-products promote wound healing and can be used as an alternative to antibiotics to treat ulcer infections caused by resistant bacteria.

Dose-Dependent Effects of Common Antibiotics Used to Treat Staphylococcus aureus on Biofilm Formation.

BACKGROUND & OBJECTIVE: Staphylococcus aureus, especially methicillin-resistant S. aureus (MRSA), represent serious nosocomial and community infections. Biofilm formation as an important virulence factor may be affected by sub-inhibitory levels of antibiotics. Few studies examined the effects of all therapeutic antimicrobial agents on clinical S.aureus. The current study aimed at observing the inducing and reducing effects of antibiotics, commonly used to treat staphylococcal infections on the production of staphylococcal biofilm. METHODS: Four MRSA (1ATCC and 3 clinical) and 1 methicillin-susceptible Staphylococcus aureus (MSSA) strains with biofilm forming ability, evaluated by the Congo red agar (CRA) plate test, were employed. Biofilm formation was measured by crystal violet microtiter plate assay. Cefazolin, rifampicin, vancomycin, oxacillin, clindamycin, cotrimoxazole, minocycline, linezolid, azithromycin, and clarithromycin were added to wells ranging from 0.06to 128 µg/mL (1× to 1/1024 MIC dependent on the MIC value of each strain). RESULTS: The current study showed that azithromycin and vancomycin had a significant inducing effect on biofilm formation. In contrast, linezolid, cefazolin, and clarithromycin, and in the second place, clindamycin and minocycline could inhibit the level of biofilm production in the sub-minimal inhibitory concentrations. CONCLUSION: The findings demonstrated that the biofilm formation as an important virulence factor may be affected by the subinhibitory levels of antibiotics.

Probiotics Lactobacillus plantarum and bifidobacterium B94: cognitive function in demyelinated model.

BACKGROUND: Multiple Sclerosis (MS) is a disease of the immune system that creates damage of Learning and memory in that. Using probiotic supplements is recommended for preventing MS disease and improving memory. This study aimed to investigate the effect of Lactobacillus plantarum (LP) and bifidobacterium B94 (BB94), on acquisition phase of spatial memory in the local demyelination of rats` hippocampus. METHODS: In this study, 32 male Wistar rats were divided into control, damage group and treatment groups. Treatment groups were including (LP) and (BB94). After the induction of demyelination by 3 µl of EB into the right dentate gyrus of the hippocampus in treatment groups, 1.5×10(8) probiotic bacteria were administered by gavage for 28 days. Data was analyzed using one-way ANOVA and Tukey post-hoc tests (p≤0.05). RESULTS: Findings demonstrated that injection of EB caused a significant increase in traveled distance (p<0.01) and also escape latency (p<0.05) compared with control group. Also, effect administrations of (LP) and (BB94) on traveled distance and escape latency were reviewed, and it was determined that administration of them do not cause significant reduction in the traveled distance compared with the lesion group. Also mentioned probiotics has no significant effect on swimming speed compared with lesion and saline groups. CONCLUSION: According to some studies, probiotics have a positive impact on improving the performance of spatial memory and learning, although the results of the current study could not indicate finality of this assumption. It seems that more researches is needed on this subject.

Analysis of antibiotic consumption in burn patients.

Infection control is very important in burn care units, because burn wound infection is one of the main causes of morbidity and mortality among burn patients. Thus, the appropriate prescription of antibiotics can be helpful, but unreasonable prescription can have detrimental consequences, including greater expenses to patients and community alike. The aim of this study was to determine the effect of antibiotic therapy on the emergence of antibiotic-resistant bacteria. 525 strains of Pseudomonas aeruginosa, Acinetobacter baumannii and Staphylococcus aureus were isolated from 335 hospitalized burn patients. Antibiotic susceptibility tests were performed after identification the strains. The records of patients were audited to find the antibiotic used. The results indicated that P. aeruginosa is the most prevalent Gram-negative bacteria. Further, it showed a relation between abuse of antibiotics and emergence of antibiotic resistance. Control of resistance to antibiotics by appropriate prescription practices not only facilitates prevention of infection caused by multi-drug resistant (MDR) microorganisms, but it can also decrease the cost of treatment.