Comparative safety and efficacy of autogenous vaccine administrated by different routes against furunculosis caused by Aeromonas salmonicida sub. salmonicida in large Rainbow trout (Oncorhynchus mykiss).

The development and growth of fish farming are hindered by viral and bacterial infectious diseases, which necessitate effective disease control measures. Furunculosis, primarily caused by Aeromonas salmonicida, stands out as a significant bacterial disease affecting salmonid fish farms, particularly rainbow trout. Vaccination has emerged as a crucial tool in combating this disease. The objective of this experiment was to assess and compare the efficacy and duration of different vaccine protocols against furunculosis in large trout under controlled rearing conditions, utilizing single and booster administrations via intraperitoneal, oral, and immersion routes. Among the various vaccination protocols tested, only those involving intraperitoneal injection, administered at least once, proved truly effective in preventing the expression of clinical signs of furunculosis and reducing mortality rates. A single intraperitoneal administration provided protection for up to 2352°-days, equivalent to approximately 5 months in water at 16 °C. However, intraperitoneal vaccination may lead to reduced growth in the fish due to resultant intraperitoneal adhesions. Additionally, protocols incorporating booster doses via intraperitoneal injection demonstrated efficacy regardless of the administration route of the primary vaccination. Nevertheless, the use of booster vaccinations via the intraperitoneal route did not confer any significant advantage over a single intraperitoneal injection in terms of efficacy.

Common Skin Conditions in Children and Adolescents: Bacterial Infections.

Bacterial skin infections represent a significant health care burden. Cellulitis and erysipelas are rapidly spreading, painful, superficial skin infections, usually caused by streptococci or Staphylococcus aureus. Folliculitis is an infection of hair follicles mostly caused by S aureus. Simple folliculitis typically is self-limited. Topical benzoyl peroxide is a first-line nonantibiotic treatment. Mupirocin and clindamycin are topical antibiotic options. For treatment-resistant cases, oral cephalexin or dicloxacillin is an appropriate option. Impetigo is a common, self-limited infection in children. Bullous impetigo is caused by S aureus, and nonbullous impetigo is caused by beta-hemolytic streptococci, S aureus, or both. In most cases, topical mupirocin or retapamulin (Altabax) is effective. Oral antibiotics should be considered for household outbreaks or patients with multiple lesions. Abscesses are red, painful collections of purulence in the dermis and deeper tissues caused by S aureus or polymicrobial infections. Furuncles are abscesses of a hair follicle, whereas carbuncles involve several hair follicles. In recurrent cases of these lesions, culture of the exudate is recommended. Abscess, furuncle, and carbuncle management consists of incision and drainage. Oral antibiotics are not necessary in most cases but should be prescribed for patients with severe immunocompromise or systemic signs of infection. In bacterial skin infections, methicillin-resistant S aureus coverage should be considered for patients with infections that have not improved with treatment.

A bacterial ghost vaccine against Aeromonas salmonicida infection in turbot (Scophthalmus maximus).

Aeromonas salmonicida is one of the most prevalent pathogens that causes huge economic losses to aquaculture. Effective vaccination is the first choice for preventing infection. Bacterial ghost (BG), an empty bacterial shell devoid of cytoplasm, is a promising vaccine antigen with distinct advantages. Herein, we established strategies for producing a substantial yield of A. salmonicida ghost (ASG) and investigated the immune-protective properties of it. As a result, 2.84 mg/ml NaOH was discovered to be capable of inducing considerable amounts of ASG. Furthermore, the ASG vaccine elicited adaptive immunity in turbots after rapid activation of innate immunity. Even though formalin-killed cells (FKC) produced a few more antibodies than ASG, ASG ultimately provided a much stronger immune protection effect because it strengthened cellular immunity, with a relative percentage survival (RPS) of 50.1 % compared to FKC. These findings demonstrated that ASG effectively activated cell-mediated immunity, which helped get rid of microorganisms inside cells. Therefore, this study presented novel perspectives for future research on furunculosis vaccine products based on ASG as an antigen.

Role of cold shock proteins B and D in Aeromonas salmonicida subsp. salmonicida physiology and virulence in lumpfish (Cyclopterus lumpus).

Cold shock proteins (Csp) are pivotal nucleic acid binding proteins known for their crucial roles in the physiology and virulence of various bacterial pathogens affecting plant, insect, and mammalian hosts. However, their significance in bacterial pathogens of teleost fish remains unexplored. Aeromonas salmonicida subsp. salmonicida (hereafter A. salmonicida) is a psychrotrophic pathogen and the causative agent of furunculosis in marine and freshwater fish. Four csp genes (cspB, cspD, cspA, and cspC) have been identified in the genome of A. salmonicida J223 (wild type). Here, we evaluated the role of DNA binding proteins, CspB and CspD, in A. salmonicida physiology and virulence in lumpfish (Cyclopterus lumpus). A. salmonicida ΔcspB, ΔcspD, and the double ΔcspBΔcspD mutants were constructed and characterized. A. salmonicida ΔcspB and ΔcspBΔcspD mutants showed a faster growth at 28°C, and reduced virulence in lumpfish. A. salmonicida ΔcspD showed a slower growth at 28°C, biofilm formation, lower survival in low temperatures and freezing conditions (-20°C, 0°C, and 4°C), deficient in lipopolysaccharide synthesis, and low virulence in lumpfish. Additionally, ΔcspBΔcspD mutants showed less survival in the presence of bile compared to the wild type. Transcriptome analysis revealed that 200, 37, and 921 genes were differentially expressed in ΔcspB, ΔcspD, and ΔcspBΔcspD, respectively. In ΔcspB and ΔcspBΔcspD virulence genes in the chromosome and virulence plasmid were downregulated. Our analysis indicates that CspB and CspD mostly act as a transcriptional activator, influencing cell division (e.g., treB), virulence factors (e.g., aexT), and ultimately virulence.

Influence of Thermal Treatment on the Composition of Alpinia officinarum Rhizome.

Alpinia officinarum is a representative of the Zingiberaceae family, which is known for its wide use in the food and pharmaceutical industries also due to its precious pharmacological potential. The major aim of the present study was to evaluate the influence of thermal treatment on the composition of the rhizome of Alpinia officinarum and its antioxidant activity. The fresh rhizome was subjected to various thermal treatment processes-boiling, frying and microwave heating during various time intervals-and their composition and antioxidant activity were determined using chromatographic (HPLC - High Performance Liquid Chromatography and HPLC-MS - High Performance Liquid Chromatography Mass Spectrometry) and spectrophotometric (DPPH and TPC - Total Phenolic Content) methods. Pinobanksin was the main compound found in the extract of the fresh rhizome (537.79 mg/kg), followed by galangin (197.7 mg/kg) and zingerone (185.5 mg/kg). The effect of thermal treatment on the rhizome composition was varied. In general, thermal processing significantly decreased the content of active compounds in the rhizome. However, there were some exceptions-boiling for 4 min significantly increased the content of pinobanksin (1162.4 mg/kg) and galangin (280.7 mg/kg), and microwave processing for 4 min increased the content of pinocembrin (213 mg/kg). It was found that boiling and microwave treatment significantly increased the antioxidant activity of the processed rhizomes.

Inactivated Aeromonas salmonicida impairs adaptive immunity in lumpfish (Cyclopterus lumpus).

Aeromonas salmonicida, a widely distributed aquatic pathogen causing furunculosis in fish, exhibits varied virulence, posing challenges in infectious disease and immunity studies, notably in vaccine efficacy assessment. Lumpfish (Cyclopterus lumpus) has become a valuable model for marine pathogenesis studies. This study evaluated several antigen preparations against A. salmonicida J223, a hypervirulent strain of teleost fish, including lumpfish. The potential immune protective effect of A. salmonicida bacterins in the presence and absence of the A-layer and extracellular products was tested in lumpfish. Also, we evaluated the impact of A. salmonicida outer membrane proteins (OMPs) and iron-regulated outer membrane proteins (IROMPs) on lumpfish immunity. The immunized lumpfish were intraperitoneally (i.p.) challenged with 104 A. salmonicida cells/dose at 8 weeks-post immunization (wpi). Immunized and non-immunized fish died within 2 weeks post-challenge. Our analyses showed that immunization with A. salmonicida J223 bacterins and antigen preparations did not increase IgM titres. In addition, adaptive immunity biomarker genes (e.g., igm, mhc-ii and cd4) were down-regulated. These findings suggest that A. salmonicida J223 antigen preparations hinder lumpfish immunity. Notably, many fish vaccines are bacterin-based, often lacking efficacy evaluation. This study offers crucial insights for finfish vaccine approval and regulations.

Aeromonas salmonicida, causative agent of salmonid furunculosis, isolated from the freshwater parasitic copepod, Salmincola californiensis.

Here, we provide evidence that the freshwater parasitic copepod, Salmincola californiensis, acts as a vector for Aeromonas salmonicida. While investigating the effects of S. californiensis on Chinoook salmon (Oncorhynchus tshawytscha), we tangentially observed that fish infected with the copepod developed furunculosis, caused by A. salmonicida. This occurred despite being reared in pathogen-free well water in a research facility with no prior history of spontaneous infection. We further investigated the possibility of S. californiensis to serve as a vector for the bacterium via detection of fluorescently labelled A. salmonicida inside the egg sacs from copepods in which the fish hosts were experimentally infected with GFP-A449 A. salmonicida. We then evaluated copepod egg sacs that were collected from adult Chinook salmon from a freshwater hatchery with A. salmonicida infections confirmed by either culture or PCR. The bacterium was cultured on tryptic soy agar plates from 75% of the egg sacs, and 61% were positive by PCR. These three separate experiments indicate an alternative tactic of transmission in addition to direct transmission of A. salmonicida in captivity. The copepod may play an important role in transmission of the bacterium when fish are more dispersed, such as in the wild.

Factors that influence safe water drinking practices among older persons in slums of Kampala: Analyzing disparities in boiling water.

INTRODUCTION: Safe drinking water practice is a key public health promotion strategy for reducing the spread of waterborne diseases. The purpose of this study was to investigate the factors that influence boiling water practice among older persons in informal settlements of Kampala. METHODS: We collected primary data on "Access to safe water and health services among older persons in informal settlements of Kampala in October 2022. The study interviewed 593 men and women aged 60 years and older. The Complementary log-log multivariable technique was used to establish the association between boiling water practice and selected independent variables. RESULTS: The results show that nearly 8% of the respondents did not boil their water for drinking. The findings show that the female older persons had increased odds of boiling water to make it safe for drinking compared to their male counterparts (OR = 1.859, 95% CI = 1.384-2.495). Other factors associated with boiling water practice among older persons in the informal settlements of Kampala were; living alone, quality of house, and type of water source. CONCLUSION: Basing on our findings, we find that older women are more likely to use safe drinking water practice (boiling) compared to the male older persons. Health education majorly targeting older men about the importance and health benefits associated with safe water drinking practices should be prioritized by policy makers. There is need to improve housing conditions of older persons to minimize typhoid, diarrhea and other health risks associated with drinking unsafely managed water.

Reassessing Stephanofilaria stilesi dermatitis in cattle, with characterization of molecular markers for confirming diagnosis.

BACKGROUND: Stephanofilaria stilesi is a vector-borne filarioid nematode of cattle in North America that is transmitted via the hematophagous horn fly (Haematobia irritans) intermediate host. Despite being relatively common, little attention has been given to a thorough description of S. stilesi lesions and the potential integration of pathological and molecular diagnostic findings to confirm infection. METHODS: To characterize the cutaneous lesions caused by S. stilesi in cattle (Bos taurus taurus and Bos taurus indicus), skin of the ventral abdominal midline was collected from 22 animals during postmortem examination. Skin samples were processed for histology, transmission electron microscopy (TEM), DNA extraction, PCR, and Sanger sequencing targeting molecular markers cytochrome oxidase c subunit 1 (cox1), 12S, 18S rDNA, and 28S rDNA. RESULTS: Macroscopically, lesions ranged from 5 × 4 cm to 36 × 10 cm, consisting of one large single lesion, or two to four ovoid areas at the ventral abdominal midline, surrounding the umbilicus. Each lesion presented as ulcerative dermatitis with dry, serocellular crusts, or alopecic and lichenified areas. Histologically, eosinophilic, neutrophilic, and ulcerative dermatitis with furunculosis, folliculitis, and epidermal hyperplasia was observed. Cross sections of adult nematodes were identified in ~ 60% of the cases (n = 13) within intact follicles, sebaceous ducts, crusts, and areas of furunculosis. Stephanofilaria first-stage larvae (L1) were observed in five cases within "vitelline membranes" in the superficial dermis and crusts. Ultrastructurally, the L1 cross sections were compounded of smooth multilayered cuticle and somatic cells. The "vitelline membrane" is a tri-layered membrane where L1 are suspended in a matrix. Stephanofilaria stilesi DNA was found in 5 out of the 13 cases in which adults or L1 were histologically observed (38%) and in 1 out of the 9 cases without adults or L1 present (11%). Phylogenetic analyses suggest a closer relationship of the genus Stephanofilaria with Thelazioidea, instead of the family Filariidae (Filarioidea), in which it has been historically allocated. CONCLUSIONS: Our study improved the characterization of lesions and described ultrastructural findings of S. stilesi and highlights that molecular tools should be utilized in combination with histology for improved diagnostic resolution.

Ultrasonographic findings may be useful for differentiating interdigital abscesses secondary to migrating grass awns and interdigital furunculosis in dogs.

Grass awn migration and furunculosis are common diseases in dogs that can lead to interdigital subcutaneous lesions with a similar clinical presentation, and occasionally similar ultrasonographic images, but different treatments are required. This retrospective, multicentric, analytical study aimed to determine whether epidemiological, clinical, and ultrasonographic features could be used to differentiate interdigital furunculosis and abscesses secondary to migrating grass awns. Fifty-nine dogs that underwent interdigital ultrasonography were included (interdigital furunculosis [IDF], n = 27; interdigital abscess secondary to a migrating grass awn [IAGA], n = 32). Ultrasonographic images were reviewed by two observers blinded to the diagnosis, who graded nine qualitative and four quantitative parameters for each patient. In both groups, pruritus/licking (IDF 74%, IAGA 70%), a discharging interdigital wound (63% for each group), and thoracic limb involvement (IDF 88%, IAGA 75%) were common features. On ultrasound, a subcutaneous multilinear hyperechoic main element was identified in most dogs (IDF 85%, IAGA 100%). The ability to display this element in a single plane (P < 0.01), the absence of additional hyperechoic linear elements in different planes (P < 0.01), and a surrounding hypoechoic halo (P < 0.05) were significantly more common in dogs with interdigital abscesses secondary to migrating grass awns. A cut-off value of 0.83 cm for the length of the main multilinear element provided a sensitivity of 91% and a specificity of 87% in the diagnosis of a migrating grass awn. Findings supported prioritizing a differential diagnosis of interdigital abscesses secondary to grass awns in dogs with these ultrasonographic characteristics.