The management of herpes simplex virus infections

Brucella, a bacterium with multiple ways of causing infection

Brucellosis is a zoonotic infection caused by the intracellular gram-negative bacterium Brucella. It is the most common zoonosis worldwide, and its transmission is classically associated with consumption of unpasteurized animal products. However, other mechanisms of transmission include contact of the skin or mucous membranes with infected animal tissue. We present a case of a patient who had more than one possible route of infection.

Osteonecrosis of the femoral head due to brucellosis: a case report

BACKGROUND

Brucellosis is a zoonotic infection transmitted from infected animals to humans, osteonecrosis of the femoral head (ONFH) is a devastating disease that affects patients' life with pain, dysfunction of walking and always lead to total hip arthroplasty (THA). We presented a case of ONFH which was very likely due to the infection of Brucella spp.

CASE PRESENTATION

The patient was a 49 years-old male who was a herder living in Inner Mongolia, the northern part of China. He first showed recurrent fever then presented bilateral hip pain, which was confirmed to be brucellosis and ONFH on the right side of the hip. He was admitted to our center showed bilateral ONFH with the restrictive movement of both hips. We performed THA after it was confirmed that the infection has been cured. The patient can walk with the help of the walker the second day after surgery.

CONCLUSION

Brucellosis is still a common epidemic disease worldwide, which can lead to many complications, brucellosis arthritis is the most common complication of Brucellosis. Osteonecrosis of the femoral head can also present in the patients with brucellosis. All the patients presented with recurrent fever and hip pain, who is from the epidemic region, should be taken both septic arthritis and ONFH into consideration.

Bioactive natural products with anti-herpes simplex virus properties

Objectives

In this review, we highlight and summarise the most promising extracts, fractions and pure compounds as potential anti-herpes simplex virus (HSV) agents derived from microorganisms, marine organisms, fungi, animals and plants. The role of natural products in the development of anti-HSV drugs will be discussed.

Key findings

Herpes simplex viruses (HSV-1 and -2) are common human pathogens that remain a serious threat to human health. In recent years, a great interest has been devoted to the search for integrated management of HSV infections. Acyclovir and related nucleoside analogues have been licensed for the therapy that target viral DNA polymerase. Although these drugs are currently effective against HSV infections, the intensive use of these drugs has led to the problem of drug-resistant strains. Therefore, the search for new sources to develop new antiherpetic agents has gained major priority to overcome the problem.

Summary

Natural products as potential, new anti-HSV drugs provide several advantages such as reduced side effects, less resistance, low toxicity and various mechanisms of action. This paper aims to provide an overview of natural products that possess antiviral activity against HSV.

Expression and Validation of D-Erythrulose 1-Phosphate Dehydrogenase from Brucella abortus: A Diagnostic Reagent for Bovine Brucellosis

Brucella abortus is a bacterium of brucellosis causing abortion in cattle. The diagnosis of bovine brucellosis mainly relies on serologic tests using smooth lipopolysaccharide (S-LPS) from B. abortus. However, the usefulness of this method is limited by false-positive reactions due to cross-reaction with other Gram-negative bacteria. In the present study, the eryC gene encoding B. abortus D-erythrulose 1-phosphate dehydrogenase, which is involved in the erythritol metabolism in virulent B. abortus strain but is absent from a B. abortus vaccine strain (S19), was cloned. Recombinant EryC was expressed and purified for the evaluation as a diagnostic reagent for bovine brucellosis. Other B. abortus proteins, Omp16, PP26, and CP39 were also purified and their seroreactivities were compared. Recombinant EryC, Omp16, PP26, and PP39 were all reactive to B. abortus-positive serum. The specificity of recombinant Omp 16, PP26, CP39, and EryC, were shown to be approximately 98%, whereas that of B. abortus whole cell lysates was shown to be 95%. The sensitivity of Omp16, PP26, CP39, and EryC were 10%, 51%, 64%, and 43%, respectively, whereas that of B. abortus whole cell lysates was 53%. These results suggested that B. abortus EryC would be a potential reagent for diagnosis for bovine brucellosis as a single protein antigen.

Inhibition of herpes simplex virus by polyamines

BACKGROUND

Herpes simplex virus (HSV) establishes latent infection in humans with periodic reactivation. Acyclovir, valacyclovir and foscarnet are in medical use today against HSV type-1 (HSV-1) and type-2 (HSV-2), inhibiting the DNA synthesis of the viruses. Additional drugs that will affect the growth of these viruses by other mechanisms and also decrease the frequency of appearance of drug-resistant mutants are required.

METHODS

Cationic polysaccharides were synthesized by conjugation of various oligoamines to oxidized polysaccharides by reductive amination. Polycations of dextran, pullulan and arabinogalactan were grafted with oligoamines of 2-4 amino groups forming Schiff-base imine-based conjugates followed by reduction with borohydride to obtain the stable amine-based conjugate. Evaluation of toxicity to BS-C-1 cells and antiviral activity against HSV-1 and HSV-2 of the different compounds was performed in vitro by a semiquantitative assay. A quantitative study with a selected compound followed.

RESULTS

Structure-activity relationship studies showed that the nature of the grafted oligoamine of the polycation plays an essential role in the antiviral activity against HSV-1 and HSV-2. Dextran-propan-1,3-diamine (DPD) was found to be the most potent of all the compounds examined. DPD did not decrease the infectivity of HSV upon direct exposure to the virions. The growth of HSV was significantly inhibited when DPD was added to the host cells 1 h prior to infection, thus preventing the adsorption and penetration of the virus into the cells.

CONCLUSIONS

Our in vitro data warrant clinical investigation. DPD could have an advantage as a topical application in combination therapy of HSV lesions.

Human brucellosis in a nonendemic country: a report from Germany, 2002 and 2003

Human brucellosis has become a rare disease in Germany since the eradication of bovine and ovine/caprine brucellosis in this country. Therefore, most physicians are unfamiliar with the illnesses clinical presentation, diagnostic tools, and therapeutic strategies. This retrospective study was carried out to evaluate the epidemiological, clinical, and laboratory features of human brucellosis in Germany in the years 2002 and 2003. Thirty-one bacterial isolates from 30 patients sent to the German national reference laboratory were characterized using the genus-specific bcsp31 real-time PCR, the species-specific AMOS-PCR, and standard microbiological methods for the detection and identification of Brucella spp. The medical records of all patients with bacteriologically confirmed brucellosis were evaluated. All 31 isolates proved to be Brucella (30 Brucella melitensis and 1 Brucella suis). Most of the brucellosis patients were infected in endemic countries while visiting friends and relatives during their summer holidays. One case of laboratory-acquired infection was identified. Brucellosis was transmitted mainly by the consumption of contaminated unpasteurized milk or cheese from goats and sheep. The patients presented primarily with flu-like symptoms, i.e. fever, chills, sweating, headaches, arthralgia, and myalgia. In most cases, however, symptoms and signs of focal complications, e.g. spondylitis, endocarditis, and meningoencephalitis, predominated. The rate of complications was much higher than that in endemic countries, presumably as a result of diagnostic delay due to a low index of suspicion. In summary, physicians in nonendemic countries such as Germany must be aware of brucellosis being a possible cause of fever of unknown origin in immigrants and tourists travelling from endemic countries.

Therapeutic Options for Herpes Simplex Infections

Herpes simplex viruses are responsible for a number of disease states in infected individuals. Capable of establishing latent infection, herpes simplex can reactivate, causing pain, discomfort, and psychosocial consequences. Because no cure is available, treatment modalities for herpes simplex infection are required, from both personal and public health standpoints. To date, therapy has centered around the use of antiviral drugs to control infection and suppress recurrences. To expand the scope of available treatments, efforts have focused on the development of vaccines against herpes simplex virus and new agents such as immune response modifiers. Recent data suggest that these new agents are promising in their therapeutic potential.

Novel agents and strategies to treat herpes simplex virus infections

The quiet pandemic of herpes simplex virus (HSV) infection has plagued humanity since ancient times, causing mucocutaneous infection, such as herpes labialis and herpes genitalis. Disease symptoms often interfere with everyday activities and occasionally HSV infections are the cause of life-threatening or sight-impairing disease, especially in neonates and the immunocompromised patient population. After primary or initial infection the virus persists for life in a latent form in neurons of the host, periodically reactivating and often resulting in significant psychosocial distress for the patient. Currently, no cure is available. In the mid-1950s the first antiviral, idoxuridine, was developed for topical treatment of herpes disease and, in 1978, vidarabine was licensed for systemic use to treat HSV encephalitis. Acyclovir (Zovirax), a potent, specific and tolerable nucleosidic inhibitor of the herpes DNA polymerase, was a milestone in the development of antiviral drugs in the late 1970s. In the mid-1990s, when acyclovir became a generic drug, valacyclovir (Valtrex) and famciclovir (Famvir), prodrugs of the gold standard and penciclovir (Denavir), Vectavir), a close analogue, were launched. Though numerous approaches and strategies were tested and considerable effort was expended in the search of the next generation of an antiherpetic therapy, it proved difficult to outperform acyclovir. Notable in this regard was the award of a Nobel Prize in 1988 for the elucidation of mechanistic principles which resulted in the development of new drugs such as acyclovir. Vaccines, interleukins, interferons, therapeutic proteins, antibodies, immunomodulators and small-molecule drugs with specific or nonspecific modes of action lacked either efficacy or the required safety profile to replace the nucleosidic drugs acyclovir, valacyclovir, penciclovir and famciclovir as the first choice of treatment. Recently though, new inhibitors of the HSV helicase-primase with potent in vitro antiherpes activity, novel mechanisms of action, low resistance rates and superior efficacy against HSV in animal models have been discovered. This review summarises the current therapeutic options, discusses the potential of preclinical or investigational drugs and provides an up-to-date interpretation of the challenge to establish novel treatments for herpes simplex disease.