Cat-scratch disease: a rare cause of osteomyelitis.

Cat-scratch disease is a zoonosis caused by Bartonella henselae, characterised by regional lymphadenopathy. Rarer presentations, such as osteomyelitis, can occur.We present an adolescent girl with severe right lumbar pain and fever, without animal contacts or recent travels. On examination, pain on flexion of torso, movement limitation and marked lordosis were noted, but there were no inflammatory signs, palpable masses or lymph nodes. Serological investigations revealed elevated inflammatory markers. Imaging revealed a paravertebral abscess with bone erosion. Several microbiological agents were ruled out. After a second CT-guided biopsy, PCR for Bartonella spp was positive. At this point, the family recalled having a young cat some time before. Cat-scratch disease was diagnosed, and complete recovery achieved after treatment with doxycycline and rifampicin.Cat-scratch disease is a challenging diagnosis in the absence of typical features. However, B. henselae must be investigated if common pathogens are ruled out and response to therapy is poor.

Perceptions about doxycycline post-exposure prophylaxis (Doxy-PEP) as an STI-prevention strategy among gay and bisexual men (GBM) in the United States: Results from a qualitative study.

OBJECTIVE: To leverage qualitative data to explore gay and bisexual men's (GBM) perceptions about doxycycline post-exposure prophylaxis (Doxy-PEP). Doxy-PEP is a novel biomedical STI-prevention strategy that helps reduce the risk of acquiring bacterial STIs. Little is known about Doxy-PEP's acceptability in the U.S., nor how best to engage those most vulnerable to STIs in taking up this nascent prevention strategy. METHOD: Between July and September of 2023, 24 GBM from across the U.S. completed qualitative interviews about their perceptions regarding Doxy-PEP. Interviews were analyzed using a codebook approach to thematic analysis. RESULTS: Participants were generally interested in using Doxy-PEP, but were concerned about the potential for antibiotic resistance, side-effects, medication interactions to occur, along with stigmatizing discourse around its use. Meanwhile, participants were motivated by the simplicity of Doxy-PEP and the protection it could confer on both an individual and community-level- as well as its potential to reduce STI-related anxiety. Finally, participants desired additional information on Doxy-PEP to address their concerns. CONCLUSIONS: There is a need for clear guidelines and expanded public health messaging on Doxy-PEP in the U.S.

Doxycycline protects against sepsis-induced endothelial glycocalyx shedding.

Endothelial glycocalyx (eGC) covers the inner surface of the vessels and plays a role in vascular homeostasis. Syndecan is considered the "backbone" of this structure. Several studies have shown eGC shedding in sepsis and its involvement in organ dysfunction. Matrix metalloproteinases (MMP) contribute to eGC shedding through their ability for syndecan-1 cleavage. This study aimed to investigate if doxycycline, a potent MMP inhibitor, could protect against eGC shedding in lipopolysaccharide (LPS)-induced sepsis and if it could interrupt the vascular hyperpermeability, neutrophil transmigration, and microvascular impairment. Rats that received pretreatment with doxycycline before LPS displayed ultrastructural preservation of the eGC observed using transmission electronic microscopy of the lung and heart. In addition, these animals exhibited lower serum syndecan-1 levels, a biomarker of eGC injury, and lower perfused boundary region (PBR) in the mesenteric video capillaroscopy, which is inversely related to the eGC thickness compared with rats that only received LPS. Furthermore, this study revealed that doxycycline decreased sepsis-related vascular hyperpermeability in the lung and heart, reduced neutrophil transmigration in the peritoneal lavage and inside the lungs, and improved some microvascular parameters. These findings suggest that doxycycline protects against LPS-induced eGC shedding, and it could reduce vascular hyperpermeability, neutrophils transmigration, and microvascular impairment.

The impact of socio-environmental factors on doxycycline post-exposure prophylaxis awareness in the US: a cross-sectional study.

Background We investigated awareness and use of doxycycline post-exposure prophylaxis (doxyPEP) in the US. DoxyPEP has preventative benefits for bacterial STIs among people assigned male at birth. We considered how individual, interpersonal and social determinants of health, such as state-level LGBTQ equality, impact doxyPEP awareness. Methods We conducted an online snapshot cross-sectional survey in June 2023. Survey questions included demographics, sexual and substance use behaviours, and socio-environmental factors, and provided a short explanation of doxyPEP, with questions regarding prior awareness and use. Results Among a racially diverse sample of 196 participants (median age 33 years), 94% identified as cisgender men, 26% were aware of doxyPEP, whereas only 14 (7%) had ever used it. Factors significantly associated with awareness included being college educated (OR 2.50, 95% CI 1.09-5.74), a past year bacterial STI (OR 4.20, 95% CI 1.97-8.89), having discussed HIV pre-exposure prophylaxis with a health care provider (OR 3.88, 95% CI 1.99-7.57) and having taken HIV pre-exposure prophylaxis (OR 2.29, 95% CI 1.11-4.70). Socio-environmental factors associated with doxyPEP awareness included living in a large urban city (OR 2.14, 95% CI 1.12-4.10) and living in a state with higher levels of LGBTQ policy equality (OR 2.18, 95% CI 1.07-4.44). Conclusions Considering the disproportionate impact of bacterial STIs on men who have sex with men, especially those living in lower LGBTQ equality regions, such as the Southern US, our study emphasises how socio-environmental factors may limit awareness and uptake of novel biomedical approaches that have the potential to prevent morbidity and enhance sexual health.

Molecular imprinting-based triple-emission ratiometric fluorescence sensor with aggregation-induced emission effect for visual detection of doxycycline.

The development of high-performance sensors for doxycycline (DOX) detection is necessary because its residue accumulation will cause serious harm to human health and the environment. Here, a novel tri-emission ratiometric fluorescence sensor was proposed by using "post-mixing" strategy of different emissions fluorescence molecularly imprinted polymers with salicylamide as dummy template (DMIPs). BSA was chosen as assistant functional monomer, and also acted as sensitizers for the aggregation-induced emission (AIE) effect of DOX. The blue-emitting carbon dots and the red-emitting CdTe quantum dots were separately introduced into DMIPs as the response signals. Upon DOX recognition within 2 min, blue and red fluorescence of the tri-emission DMIPs sensor were quenched while green fluorescence of DOX was enhanced, resulting in a wide range of color variations observed over bluish violet-rosered-light pink-orange-yellow-green with a detection limit of 0.061 µM. The sensor possessed highly selective recognition and was successfully applied to detect DOX in complicated real samples. Moreover, with the fluorescent color collection and data processing, the smartphone-assisted visual detection of the sensors showed satisfied sensitivity with low detection limit. This work provides great potential applications for rapid and visual detection of antibiotics in complex substrates.

Treatment of peri-implantitis using nonsurgical debridement combined with bioresorbable doxycycline nanospheres: a case report with 3-year follow-up.

Treatment of peri-implant diseases focuses on reducing the bacterial load and consequent infection control. The use of local antimicrobials as an adjunct to mechanical therapy may result in a better outcome. Among antimicrobials, doxycycline stands out because of its local modulation of cytokines, microbial reduction, and clinical parameters in the treatment of periodontal diseases. The objective of this case report was to describe the combined application of mechanical debridement and bioresorbable doxycycline-loaded nanospheres for the treatment of peri-implantitis in a 71-year-old man. At the 3-year evaluation, the peri-implant tissues had improved, showing decreased probing depths, an absence of bleeding on probing, and no suppuration. This case report highlights the importance of supportive therapy, which is essential for the long-term success of peri-implantitis treatment.

Doxycycline as Postsexual Exposure Prophylaxis: Use, Acceptability, and Associated Sexual Health Behaviors Among a Multi-Site Sample of Clinical Trial Participants.

Doxycycline postexposure prophylaxis (doxy-PEP) reduces sexually transmitted infections (STIs) in men who have sex with men (MSM) and transgender women (TGW). In a clinical trial of doxy-PEP, we sought to assess acceptability, impact, and meaning of doxy-PEP use among MSM/TGW. We conducted semistructured, in-depth 1:1 interviews with MSM and TGW enrolled in the intervention arm of the Doxy-PEP study. We queried motivations for and meaning of use, attitudes, beliefs, adherence, effect on sexual behaviors, and partner, community, and structural factors related to use. We coded interview transcripts into content areas, followed by thematic analysis. We interviewed 44 participants (median age 38), 2% were TGW, 17% Black, 61% White, 30% Hispanic, and 45% persons with HIV. We identified three overarching themes. First, participants found doxy-PEP acceptable, and believed it was effective based on their history of STIs, easy to adhere to, and acceptable to sex partners. Second, doxy-PEP benefited their quality of life and mental health, offering "peace of mind" by reducing their anxiety about acquisition or unwitting transmission of STIs. Participants reported feeling more "in control" of preventing STIs, and positive about supporting their personal, partner, and community health. Third, impact on sexual behavior was variable, with most reporting no change or a brief initial change. Participants in a multi-site clinical trial of doxycycline for STI prevention perceived it to be efficacious, and that it provided quality-of-life benefits, including reduced anxiety and sense of control over sexual health. Doxy-PEP had limited impact on sexual behavior. Clinicaltrials.gov: NCT03980223.

Leptospira-specific immunoglobulin Y (IgY) is protective in infected hamsters.

Leptospirosis, a globally significant zoonotic disease caused by pathogenic Leptospira, continues to threaten the health and public safety of both humans and animals. Current clinical treatment of leptospirosis mainly relies on antibiotics but their efficacy in severe cases is controversial. Passive immunization has a protective effect in the treatment of infectious diseases. In addition, chicken egg yolk antibody (IgY) has gained increasing attention as a safe passive immunization agent. This study aimed to investigate whether hens produce specific IgY after immunization with inactivated Leptospira and the protective effect of specific IgY against leptospirosis. First, it was demonstrated that specific IgY could be extracted from the eggs of hens vaccinated with inactivated Leptospira and that specific IgY can specifically recognize and bind homotypic Leptospira with a high titre, as shown by MAT and ELISA. Next, we tested the therapeutic effects of IgY in early and late leptospirosis using a hamster model. The results showed that early specific IgY treatment increased the survival rate of hamsters to 100%, alleviated pathological damage to the liver, kidney, and lung, reduced leptospiral burden, and restored haematological indices as well as functional indicators of the liver and kidney. The therapeutic effect of early specific IgY was comparable to that of doxycycline. Late IgY treatment also enhanced the survival rate of hamsters and improved the symptoms of leptospirosis similar to early IgY treatment. However, the therapeutic effect of late IgY treatment was better when combined with doxycycline. Furthermore, no Leptospira colonization was observed in the kidneys, livers, or lungs of the surviving hamsters treated with specific IgY. Mechanistically, IgY was found to inhibit the growth and adhesion to cells of Leptospira. In conclusion, passive immunotherapy with specific IgY can be considered an effective treatment for leptospirosis, and may replace antibiotics regarding its therapeutic effects.

Efficacy and safety of antibiotics for treatment of leptospirosis: a systematic review and network meta-analysis.

BACKGROUND: Leptospirosis, an important zoonotic bacterial disease, commonly affects resource-poor populations and results in significant morbidity and mortality worldwide. The value of antibiotics in leptospirosis remains unclear, as evidenced by the conflicting opinions published. METHODS: We conducted a search in the PubMed, Web of Science, and Cochrane Library databases for studies. These studies included clinical trials and retrospective studies that evaluated the efficacy or safety of antibiotics for leptospirosis treatment. The primary outcomes assessed were defervescence time, mortality rate, and hospital stays. Subgroup analyses were performed based on whether there were cases involving children and whether there were cases of severe jaundice. Safety was defined as the prevalence of adverse events associated with the use of antibiotics. p scores were utilized to rank the efficacy of the antibiotics. RESULTS: There are included 9 randomized controlled trials (RCTs), 1 control trial (CT), and 3 retrospective studies (RS) involving 920 patients and 8 antibiotics. Six antibiotics resulted in significantly shorter defervescence times compared to the control, namely cefotaxime (MD, - 1.88; 95% CI = - 2.60 to - 1.15), azithromycin (MD, - 1.74; 95% CI = - 2.52 to - 0.95), doxycycline (MD, - 1.53; 95% CI = - 2.05 to - 1.00), ceftriaxone (MD, - 1.22; 95% CI = - 1.89 to - 0.55), penicillin (MD, - 1.22; 95% CI = - 1.80 to - 0.64), and penicillin or ampicillin (MD, - 0.08; 95% CI = - 1.01 to - 0.59). The antibiotics were not effective in reducing the mortality and hospital stays. Common adverse reactions to antibiotics included Jarisch-Herxheimer reaction, rash, headache, and digestive reactions (nausea, vomiting, diarrhea, abdominal pain, and others). CONCLUSIONS: Findings recommend that leptospirosis patients be treated with antibiotics, which significantly reduced the leptospirosis defervescence time. Cephalosporins, doxycycline, and penicillin are suggested, and azithromycin may be a suitable alternative for drug-resistant cases. SYSTEMATIC REVIEW REGISTRATION: PROSPERO CRD42022354938.

Mycoplasma hominis peritonitis after oocyte donation.

We report the case of a young, immunocompetent, non-pregnant woman diagnosed with acute abdomen 3 weeks after an ultrasound-guided transvaginal oocyte retrieval (TVOR). Peritoneal fluid, obtained during exploratory laparoscopy, yielded Mycoplasma hominis as the sole pathogen. The patient's symptoms and signs improved after 24-hour treatment with intravenous clindamycin, ampicillin and gentamycin. Complete resolution was achieved with oral doxycycline for 14 days.

A combined experimental and theoretical approach for doxycycline sensing using simple fluorescent probe with distinct fluorescence change in wide range of interferences.

Overuse of doxycycline (DOXY) can cause serious problems to human health, environment and food quality. So, it is essential to develop a new sensing methodology that is both sensitive and selective for the quantitative detection of DOXY. In our current research, we synthesized a simple fluorescent probe 4,4'-bis(benzyloxy)-1,1'-biphenyl (BBP) for the highly selective detection of doxycycline by through fluorescence spectroscopy. The probe BBP displayed ultra-sensitivity towards doxycycline due to Forster resonance energy transfer (FRET). Fluorescence spectroscopy, density functional theory (DFT), 1H NMR titration, UV-Vis, and Job's plot were used to confirm the sensing mechanism. The charge transfer between the probe and analyte was further examined qualitatively by electron density differences (EDD) and quantitively by natural bond orbital (NBO) analyses. Whereas the non-covalent nature of probe BBP towards DOXY was verified by theoretical non-covalent interaction (NCI) analysis as along with Bader's quantum theory of atoms in molecules (QTAIM) analysis. Furthermore, probe BBP was also practically employed for the detection of doxycycline in fish samples, pharmaceutical wastewater and blood samples.

Study on Drug Resistance to Treatment for Ureaplasma Urealyticum Infections in the Female Genital Tract.

BACKGROUND: Ureaplasma urealyticum (U. urealyticum) commonly occurs in female genitourinary infections, and its different biovars and serotypes have varying degrees of resistance to different antibiotics. This study aimed to ex-plore the characteristics of U. urealyticum infection and drug-resistant profiles in Chinese females. METHODS: We included 1,045 females with genital tract infections who visited Tangshan Workers' Hospital and Tangshan Maternal and Child Health Center from September 2017 to December 2018. The bacteria were selectively cultured, and drug sensitivity experiments were conducted. Eight pairs of oligonucleotide primers were designed, and polymerase chain reaction (PCR) was performed to amplify specific DNA fragments to perform bacterial strain typing. RESULTS: Among the 1,045 participants included, 566 (54.11%) participants were positive for mycoplasma infection. There were 432 (41.34%) participants with U. urealyticum infection, accounting for 76.33% of the positive participants. The infection rate of U. urealyticum was the highest in females who were 21 - 30 years old, followed by those who were 31 - 40 years old. Ureaplasma urealyticum showed the highest sensitivity to tetracyclines and the greatest resistance to quinolones. The biovar 1 of U. urealyticum with the highest detection rate of serotype 4, accounted for 66.88%. The biovar 2 of U. urealyticum mainly showed mixed subtypes 2 and 3. Biovar 2 showed higher resistance to sparfloxacin, clarithromycin, josamycin, and doxycycline than biovar 1. CONCLUSIONS: Women might be more susceptible to U. urealyticum, especially if they are of childbearing age. Urea-plasma urealyticum is mainly caused by a single serotype 6 infection. The resistance of U. urealyticum to quinolone (e.g., norfloxacin) is a great concern. Sparfloxacin, clarithromycin, ciprofloxacin, and doxycycline might be more suitable for people with biovar 1 infection. Biotyping may facilitate clinical drug use and help avoid the emergence of drug-resistant strains.

A case report of Vancomycin in the treatment of Q fever endocarditis.

The patient, a 43-year-old male, was admitted to the hospital with gradually aggravated exertional palpitations and chest tightness over a 2-day period. Upon hospital admission, a cardiac ultrasound revealed aortic valve redundancy, however multiple blood culture investigations came back negative. Blood mNGS was perfected, revealing Coxiella burnetii, and the diagnosis of Q fever (query fever) was established. The temperature and inflammatory indices of the patient were all normal with the treatment of vancomycin before cardiac surgery. But for the potential liver damage of and the Coxiella burnetii was still positive in the anti-phase II IgG titer, the doxycycline and hydroxychloroquine instead of vancomycin were applied for the patient. Despite receiving standardized anti-infective therapy of doxycycline combined with hydroxychloroquine, this patient had fever and increased leukocytes following surgery. After the addition of vancomycin as an anti-infective treatment, the temperature and leukocytes improved quickly. During the treatment of vancomycin, a discovery of liver injury may have resulted. These findings provide new therapy options for future professionals.

Immunoglobulin replacement vs prophylactic antibiotics for hypogammaglobulinemia secondary to hematological malignancy.

ABSTRACT: Immunoglobulin replacement and prophylactic antibiotics are commonly used to prevent infections in patients with secondary hypogammaglobulinemia due to hematological malignancies but have never been directly compared. In this randomized controlled feasibility trial conducted in 7 hospitals in Australia and New Zealand, we enrolled patients with secondary hypogammaglobulinemia with either a history of recurrent/severe infection or an immunoglobulin G level <4 g/L. Participants were randomized in a 1:2 ratio to immunoglobulin (0.4 g/kg per 4 weeks IV) or daily antibiotics (trimethoprim-sulfamethoxazole 160 mg/800 mg or, if contraindicated, 100 mg doxycycline) for 12 months. Participants allocated to antibiotics were allowed to crossover after grade ≥3 infections. The primary outcome was proportion of patients alive on the assigned treatment 12 months after randomization. Between August 2017 and April 2019, 63 patients were randomized: 42 to antibiotics and 21 to immunoglobulin. Proportion of participants alive on allocated treatment at 12 months was 76% in the immunoglobulin and 71% in the antibiotic arm (Fisher exact test P=.77; odds ratio, 0.78; 95% CI, 0.22-2.52). The lower quartile for time to first major infection (median, not reached) was 11.1 months for the immunoglobulin and 9.7 months for the antibiotic arm (log-rank test, P=.65). Three participants in the immunoglobulin and 2 in the antibiotic arm had grade ≥3 treatment-related adverse events. A similar proportion of participants remained on antibiotic prophylaxis at 12 months to those on immunoglobulin, with similar rates of major infections. Our findings support the feasibility of progressing to a phase 3 trial. Trial registration #ACTRN12616001723471.

Extended blood stage sensitivity profiles of Plasmodium cynomolgi to doxycycline and tafenoquine, as a model for Plasmodium vivax.

Testing Plasmodium vivax antimicrobial sensitivity is limited to ex vivo schizont maturation assays, which preclude determining the IC50s of delayed action antimalarials such as doxycycline. Using Plasmodium cynomolgi as a model for P. vivax, we determined the physiologically significant delayed death effect induced by doxycycline [IC50(96 h), 1,401 ± 607 nM]. As expected, IC50(96 h) to chloroquine (20.4 nM), piperaquine (12.6 µM), and tafenoquine (1,424 nM) were not affected by extended exposure.

Epsilon-poly-l-lysine microneedle patch loaded with amorphous doxycycline nanoparticles for synergistic treatment of skin infection.

The development of antibiotic-loaded microneedles has been hindered for years by limited excipient options, restricted drug-loading space, poor microneedle formability, and short-term drug retention. Therefore, this study proposes a dissolving microneedle fabricated from the host-defense peptide ε-poly-l-lysine (EPL) as an antibacterial adjuvant system for delivering antibiotics. EPL serves not only as a major matrix material for the microneedle tips, but also as a broad-spectrum antibacterial agent that facilitates the intracellular accumulation of the antibiotic doxycycline (DOX) by increasing bacterial cell membrane permeability. Furthermore, the formation of physically crosslinked networks of EPL affords microneedle tips with improved formability, good mechanical properties, and amorphous nanoparticles (approximately 7.2 nm) of encapsulated DOX. As a result, a high total loading content of both antimicrobials up to 2319.1 µg/patch is achieved for efficient transdermal drug delivery. In a Pseudomonas aeruginosa-induced deep cutaneous infection model, the EPL microneedles demonstrates potent and long-term effects by synergistically enhancing antibiotic activities and prolonging drug retention in infected lesions, resulting in remarkable therapeutic efficacy with 99.91 % (3.04 log) reduction in skin bacterial burden after a single administration. Overall, our study highlights the distinct advantages of EPL microneedles and their potential in clinical antibacterial practice when loaded with amorphous DOX nanoparticles.