Phytochemicals are effective and are gaining attention in fighting against drug-resistant bacterial strains. In the present study, rutin and quercetin were tested for antibacterial, antibiofilm, and wound healing activities on excision wounds infected with MDR-P. aeruginosa in diabetic mice. Antibacterial and antibiofilm activities were studied in vitro using broth dilution assay and crystal violet assay, respectively. These phytochemicals were tested alone for wound-healing activities at different concentrations (0.5% and 1% in ointment base) and in combination with gentamicin to evaluate any additive effects. Rutin and quercetin demonstrated effectiveness against MDR-P. aeruginosa at higher concentrations. Both phytochemicals inhibited biofilm formation in vitro and contributed to the healing of diabetic wounds by eradicating biofilm in the wounded tissue. Rutin at a low concentration (0.5%) had a lesser effect on reducing the epithelization period and regeneration of the epithelial layer compared to quercetin. When combined with gentamicin, quercetin (1%) displayed the maximum effect on epithelium regeneration, followed by rutin (1%) in combination with gentamicin. Both phytochemicals were found to be more effective in controlling biofilm and wound-healing activities when used as an additive with gentamicin. The study supports the traditional use of phytochemicals with antibacterial, antibiofilm, and wound-healing activities in managing diabetic infections.

Background: Obesity and type 2 diabetes (T2D) pose global health problems that continue to rise. A chronic low-grade inflammation and activation of the immune system are well established in both conditions. The presence of these factors can predict disease development and progression. Emerging evidence suggests that platelet–high density lipoprotein ratio (PHR) is a potential inflammatory marker. The purpose of this study was to investigate the relationship between PHR and T2D among obese patients. Methods: 203 patients with BMI ≥ 30 kg/m² participated in the study. Patients were categorized into two groups: non-diabetic obese and diabetic obese. Comorbidities, baseline characteristics, laboratory data, as well as PHR levels of the study groups were analyzed. Medians, risk assessment, and the diagnostic performance of PHR values were examined in both groups. Results: In obese patients, the median PHR were significantly increased in obese patients with T2D compared to non-diabetic obese (p < 0.0001). Furthermore, T2D obese with high PHR had a significantly higher FBG and HbA1c (p < 0.05). Although PHR was weakly yet significantly correlated with glycemic markers, ROC curve analysis of the PHR indicated an AUC of 0.700 (p < 0.0001) in predicting T2D in obese patients, and the cutoff value was 6.96, with a sensitivity and specificity of 53.4% and 76.1%, respectively. Moreover, increased PHR (OR = 4.77, p < 0.0001) carried a significantly higher risk for developing T2D in obese individuals. Conclusions: The PHR is a convenient and cost-effective marker that can reliably predict the presence of T2D in high-risk obese population.

Glycerol utilization as a carbohydrate source by Borreliella burgdorferi , the Lyme disease spirochete, is critical for its successful colonization and persistence in the tick vector. The expression of the glpFKD ( glp ) operon, which encodes proteins for glycerol uptake/utilization, must be tightly regulated during the enzootic cycle of B. burgdorferi . Previous studies have established that the second messenger cyclic di-GMP (c-di-GMP) is required for the activation of glp expression, while an alternative sigma factor RpoS acts as a negative regulator for glp expression. In the present study, we report identification of a cis element within the 5´ untranslated region of glp that exerts negative regulation of glp expression. Further genetic screen of known and predicted DNA-binding proteins encoded in the genome of B. burgdorferi uncovered that overexpressing Borrelia host adaptation regulator (BadR), a known global regulator, dramatically reduced glp expression. Similarly, the badR mutant significantly increased glp expression. Subsequent electrophoretic mobility shift assay analyses demonstrated that BadR directly binds to this cis element, thereby repressing glp independent of RpoS-mediated repression. The efficiency of BadR binding was further assessed in the presence of c-di-GMP and various carbohydrates. This finding highlights multi-layered positive and negative regulatory mechanisms employed by B. burgdorferi to synchronize glp expression throughout its enzootic cycle. IMPORTANCE: Borreliella burgdorferi , the Lyme disease pathogen, must modulate its gene expression differentially to adapt successfully to its two disparate hosts. Previous studies have demonstrated that the glycerol uptake and utilization operon, glpFKD , plays a crucial role in spirochetal survival within ticks. However, the glpFKD expression must be repressed when B. burgdorferi transitions to the mammalian host. In this study, we identified a specific cis element responsible for the repression of glpFKD . We further pinpointed Borrelia host adaptation regulator as the direct binding protein to this cis element, thereby repressing glpFKD expression. This discovery paves the way for a deeper exploration of how zoonotic pathogens sense distinct hosts and switch their carbon source utilization during transmission.

Borrelia burgdorferi , the pathogen of Lyme disease, differentially produces many outer surface proteins (Osp), some of which represent the most abundant membrane proteins, such as OspA, OspB, and OspC. In cultured bacteria, these proteins can account for a substantial fraction of the total cellular or membrane proteins, posing challenges to the identification and analysis of non-abundant proteins, which could serve as novel pathogen detection markers or as vaccine candidates. Herein, we introduced serial mutations to remove these abundant Osps and generated a B. burgdorferi mutant deficient in OspA, OspB, and OspC in an infectious 297-isolate background, designated as Osp ^{ABC −} mutant. Compared to parental isolate, the mutant did not reflect growth defects in the cultured medium but showed differential mRNA expression of representative tested genes, in addition to gross changes in cellular and membrane protein profiles. The analysis of differentially detectable protein contents of the Osp ^{ABC −} mutant, as compared to the wild type, by two-dimensional gel electrophoresis followed by liquid chromatography-mass spectrometry, identified several spirochete proteins that are dominated by proteins of unknown functions, as well as membrane transporters, chaperons, and metabolic enzymes. We produced recombinant forms of two of these represented proteins, BBA34 and BB0238, and showed that these proteins are detectable during spirochete infection in the tick-borne murine model of Lyme borreliosis and thus serve as potential antigenic markers of the infection. IMPORTANCE: The present manuscript employed a systemic approach to identify non-abundant proteins in cultured Borrelia burgdorferi that are otherwise masked or hidden due to the overwhelming presence of abundant Osps like OspA, OspB, and OspC. As these Osps are either absent or transiently expressed in mammals, we performed a proof-of-concept study in which their removal allowed the analysis of otherwise less abundant antigens in OspABC-deficient mutants and identified several immunogenic proteins, including BBA34 and BB0238. These antigens could serve as novel vaccine candidates and/or genetic markers of Lyme borreliosis, promoting new research in the clinical diagnosis and prevention of Lyme disease.

In Borrelia burgdorferi , the causative agent of Lyme disease, differential gene expression is primarily governed by the alternative sigma factor RpoS (σ ^S ). Understanding the regulation of RpoS is crucial for elucidating how B. burgdorferi is maintained throughout its enzootic cycle. Our recent studies have shown that the homolog of Fur/PerR repressor/activator BosR functions as an RNA-binding protein that controls the rpoS mRNA stability. However, the mechanisms regulating BosR, particularly in response to host signals and environmental cues, remain largely unclear. In this study, we uncovered a positive feedback loop between RpoS and BosR, wherein RpoS post-transcriptionally regulates BosR levels. Specifically, mutation or deletion of rpoS significantly reduced BosR levels, whereas artificial induction of rpoS resulted in a dose-dependent increase in BosR levels. Notably, RpoS does not affect bosR mRNA levels but instead modulates the turnover rate of the BosR protein. Moreover, we demonstrated that environmental cues do not directly influence bosR expression but instead induce rpoS transcription and RpoS production, thereby enhancing BosR protein levels. These findings reveal a new layer of complexity in the RpoN-RpoS regulatory pathway, challenging the existing paradigm and suggesting a need to re-evaluate the factors and signals previously implicated in regulating RpoS via BosR. This study provides new insights into the intricate regulatory networks underpinning B. burgdorferi ’s adaptation and survival in its enzootic cycle. IMPORTANCE: Lyme disease is the most prevalent arthropod-borne infection in the United States. The etiological agent, Borreliella (or Borrelia ) burgdorferi , is maintained in nature through an enzootic cycle involving a tick vector and a mammalian host. RpoS, the master regulator of differential gene expression, plays a crucial role in tick transmission and mammalian infection of B. burgdorferi . This study reveals a positive feedback loop between RpoS and a Fur/PerR homolog. Elucidating this regulatory network is essential for identifying potential therapeutic targets to disrupt B. burgdorferi ’s enzootic cycle. The findings also have broader implications for understanding the regulation of RpoS and Fur/PerR family in other bacteria.

Ticks are known vectors of various pathogens and are increasingly recognized as carriers of antimicrobial-resistant (AMR) bacteria. However, the role of camel ticks in AMR transmission remains poorly understood. In this study, we investigated bacteria isolated from Hyalomma dromedarii hard ticks collected from dromedary camels in Hail Province, Saudi Arabia, and assessed their AMR profiles. A total of 57 ticks were collected, yielding 29 bacterial isolates. The majority (79%; 23/29) were Gram-negative bacteria, primarily Enterobacter cloacae complex (n = 21) and Pseudomonas putida (n = 2). Gram-positive isolates (21%; 6/29) included Staphylococcus sciuri (n = 4) and Staphylococcus xylosus (n = 2). All Gram-negative isolates were resistant to cefazolin, 91% to amoxicillin/clavulanic acid, and 8.7% to trimethoprim/sulfamethoxazole, while remaining susceptible to higher-generation cephalosporins, carbapenems, and aminoglycosides. Among Gram-positive isolates, resistance to fusidic acid was universal, with occasional resistance to benzylpenicillin (33%) and erythromycin (17%). No multidrug resistance across three or more antibiotic classes was observed. These findings highlight the presence of clinically relevant AMR bacteria in camel ticks and underscore the need for targeted AMR surveillance in arid livestock regions. Such efforts are critical to understanding and mitigating AMR risks within the animal–human–environment interface of the One Health framework.