WhyD tailors surface polymers to prevent bacteriolysis and direct cell elongation in Streptococcus pneumoniae

Penicillin and related antibiotics disrupt cell wall synthesis in bacteria and induce lysis by misactivating cell wall hydrolases called autolysins. Despite the clinical importance of this phenomenon, little is known about the factors that control autolysins and how penicillins subvert this regulation to kill cells. In the pathogen Streptococcus pneumoniae (Sp), LytA is the major autolysin responsible for penicillin-induced bacteriolysis. We recently discovered that penicillin treatment of Sp causes a dramatic shift in surface polymer biogenesis in which cell wall-anchored teichoic acids (WTAs) increase in abundance at the expense of lipid-linked lipoteichoic acids. Because LytA binds to these polymers, this change recruits the enzyme to its substrate where it cleaves the cell wall and elicits lysis. In this report, we identify WhyD (SPD_0880) as a new factor that controls the level of WTAs in Sp cells to prevent LytA misactivation and lysis. We show that WhyD is a WTA hydrolase that restricts the WTA content of the wall to areas adjacent to active PG synthesis. Our results support a model in which the WTA tailoring activity of WhyD directs PG remodeling activity required for proper cell elongation in addition to preventing autolysis by LytA.

Antimicrobial Selection for the Treatment of Clinical Mastitis and the Efficacy of Penicillin Treatment Protocols in Large Estonian Dairy Herds

Clinical mastitis (CM) is the most common microbial disease treated in dairy cows. We analyzed the antimicrobial usage in cows with CM (n = 11,420) in large dairy herds (n = 43) in Estonia. CM treatment data were collected during a 12-month study period. The antimicrobial usage was observed during the 21 days from the initiation of treatment, and the incidence of antimicrobial-treated CM was calculated for each study herd. The effect of intramammary (IMM), systemic, and combined (systemic and IMM) penicillin treatment of CM on the post-treatment somatic cell count (SCC) was analyzed using the treatment records of 2222 cows from 24 herds with a mixed multivariable linear regression model. The median incidence of antimicrobial-treated CM was 35.8 per 100 cow-years. Procaine benzylpenicillin and marbofloxacin were used in 6103 (35.5%, 95% CI 34.8–36.2) and 2839 (16.5%, 95% CI 16.0–17.1) CM treatments, respectively. Post-treatment SCC was higher after IMM penicillin therapy compared to systemic or combination therapy. Treatment of CM usually included first-choice antimicrobials, but different antimicrobial combinations were also widely used. The effect of procaine benzylpenicillin to post-treatment SCC was dependent on the administration route, cow parity, and days in milk. Further studies should evaluate the factors affecting veterinarians’ choice of antimicrobial used in the treatment of CM.

Penicillin Treatment Failure in Rabbit Syphilis Due to the Persistence of Treponemes (Treponema paraluisleporidarum Ecovar Cuniculus) in the Focus of Infection

Rabbit venereal spirochetosis, a disease caused by Treponema paraluisleporidarum ecovar Cuniculus (TPeC), affects both wild and pet rabbits, and is transmitted sexually and via direct contact among animals. Treatment of syphilis in pet rabbits requires administration of antibiotics, including penicillin G, chloramphenicol, or fluoroquinolones. The aim of this work was to elucidate the cause of penicillin treatment failure in rabbit syphilis in a pet rabbit treated in Brno, Czech Republic, and to assess the phylogenetic relatedness of the agent to previously characterized pathogenic treponemes. Following amputation of the infected digits, the second round of penicillin treatment using the same dosage and application route resulted in the disappearance of clinical symptoms within a period of two weeks. The bacterium was successfully isolated from the claws, propagated in three experimental rabbits, and the resulting TPeC strain was designated as Cz-2020. Analysis of four genetic loci revealed that the Cz-2020 strain was similar but also clearly distinct from the only TPeC strain, which had been characterized in detail to date, i.e., the Cuniculi A strain, which was isolated in North America. The strain Cz-2020 represents the first available viable TPeC strain of European origin. DNA sequences encoding five penicillin-binding proteins of the strain Cz-2020 were compared to those of Cuniculi A, which is known to be sensitive to penicillin. The sequences differed in six nucleotides resulting in single amino acid changes in Penicillin-binding protein 1, 2, and 3. Since the second round of treatment was successful, we conclude that the penicillin treatment failure in the first round resulted from the presence of infection foci in claws where treponemes persisted.

Syphilis and pregnancy: Review

Syphilis is a disease that has not been eradicated in part due to inadequate management of antibiotic therapy which is selected according to the stage of the disease and to the misuse of the type of penicillin. Treatment of this disease should be done to prevent it´s chronic complications, to avoid infecting sexual partners and the fetus in a pregnant woman. Syphilis in pregnancy causes increase in the rate of recurrent abortions and neonatal morbidity and mortality, that´s the main reason why early detection and treatment without delay is extremely important. Pregnancy alters immunity, so the serological diagnosis can provide false positives, with the use of inverse algorithms these results may decrease, by increasing the sensitivity of the tests. Today, after 69 years since the advent of penicillin, it has become the drug of choice for any stage of syphilis and in pregnant women; if the patient has allergy, desensitization is indicated either orally or intravenously and other antibiotic shouldn´t be used because of the security offered by penicillin in the cure rate and in the reduction of congenital syphilis. Keywords: Syphilis; Pregnancy; Inverse algorithms.

Cauliflower-shaped lesions on a young woman’s vulva

A 20-year-old young woman with cauliflower-shaped lesions on her vulva was misdiagnosed as condyloma acuminatum. Further evaluation revealed positive serological tests for syphilis. On histological examination, and numerous plasma cells were seen to infiltrate the dermis heavily. The cauliflower-shaped lesions on vulva completely disappeared after benzathine penicillin treatment. Cauliflower-shaped lesions are a rare manifestation of secondary syphilis.

Cutaneous Anthrax: Evaluation of 27 Cases

Introduction: While the incidence of anthrax is decreasing in Turkey, it is still endemic in some regions of the country. In this study, it was aimed to develop preventive methods by determining the characteristics of cutaneous anthrax after assessing the literature over the last six years (2013-2019) of cutaneous anthrax cases in Turkey. Materials and Methods: The studies carried out in the last six years on cutaneous anthrax were examined retrospectively. Diagnosis, physical examinations, vital signs, laboratory results, medical treatments of the evaluated cases were performed and tables on demographic characteristics were developed. Results: Patients' age ranged from 8 to 65 years. A total of 13 patients (48.1%) who were assessed were males. The source of infection was contact with infected animal and its products in 23 cases (85.2%), husbandry in 2 cases (7.4%), contact with infected blood in one case (3.7%), and being in the same environment with an anthrax diagnosed patient in one case (3.7%). As a result of microbiological investigations, it was found out that 10 patients (37%) had Bacillus anthracis. All patients received penicillin treatment. Only three patients were surgically treated. Treatment resulted in recovery in 26 cases. Conclusion: In order to prevent the disease, preventive measures such as training of risky individuals dealing with animal husbandry and vaccination of animals will reduce the incidence of the disease.

Nonvenereal endemic treponematoses: Yaws, endemic syphilis (bejel), and pinta

The endemic treponematoses are chronic, granulomatous diseases caused by morphologically and serologically identical spirochaetes of the genus Treponema. They are spread by intimate but non-sexual contact and possibly by fomites, mainly among children. Treponema pallidum subsp. pertenue causing yaws (framboesia), T. pallidum subsp. endemicum causing endemic syphilis (bejel) and T. carateum causing pinta (carate) are distinguishable from T. pallidum subsp. pallidum, causing venereal syphilis, by their epidemiology and pathological effects and genomic structure (e.g. the arp gene). Despite the successful WHO/UNICEF mass penicillin treatment campaign (1952–1964), there has been a resurgence of yaws, mainly in West Africa, Southeast Asia, and the Pacific. Children living in rural areas in warm, humid climates in tropical countries are most affected by yaws. About 10% of untreated cases develop late, disfiguring, or crippling lesions of skin, bone, and cartilage.