Pulmonary actinomycosis: cytomorphological features

Pulmonary actinomycosis is an uncommon infectious disease. Although the gold standard for diagnosis is histological examination with bacterial culture of lung tissue, cytology samples offer a fast and low-cost alternate diagnostic procedure. The cytology literature on this topic is limited to mostly case reports. Therefore, the aim of this study was to review cytological material in a series of patients with a diagnosis of pulmonary actinomycosis to characterize the main cytomorphological findings. Different cytological respiratory samples including sputum smears, bronchoalveolar lavages (BALs), transthoracic or endobronchial fine needle aspiration cytology (FNAC) and cell block preparations were used for retrospective examination. For all cases patient age, gender, symptoms, and radiological chest findings were recorded. A total of 26 cytological respiratory samples (14 sputum smears, 9 FNAC, two BALs) including direct smears and 6 cell blocks from 9 patients were examined. In sputum smears the most remarkable findings were the presence of dark cotton ball masses with projections like spider legs and/or mouse tails (75% of the samples). Sulfur granules were observed in 4 (40%) of the sputum smears and within FNAC cases. Various respiratory cytology samples including sputum smears, FNAC and BALs can reveal cytomorphological findings diagnostic of pulmonary actinomycosis. Characteristic cytological findings compatible with a diagnosis of this infection include cotton ball masses and less frequently sulfur granules.

“Candidatus Thiovulum sp. strain imperiosus”: The largest free-living epsilon proteobacteraeota Thiovulum strain lives in marine mangrove environment.

A large (47.75±3.56 µm in diameter) Thiovulum bacterial strain forming white veils is described from marine mangrove ecosystem. High sulfide concentrations (up to 8 mM of H2S) were measured on the sunken organic matters (wood/bone debris) in laboratory conditions. This sulfur-oxidizing bacterium colonized such organic matter forming white veil. According to conventional scanning electron microscope (SEM) observations, bacterial cells are ovoid and slightly motile by numerous small flagella present through the cell surface. Intracytoplasmic large internal sulfur granules were shown suggesting a sulphidic-based metabolism. Observations were confirmed by sulfur elemental sulfur distribution detected by energy-dispersive X-ray spectroscopy (EDXS) analysis using environmental scanning electron microscope (ESEM) on non-dehydrated samples. Phylogenetic analysis of partial sequence of 16S rDNA obtained from purified fractions of this -proteobacteraeota strain indicates that this bacterium belongs to the Thiovulaceae cluster and could be one of the largest Thiovulum ever described. We propose to name this species “Candidatus Thiovulum sp. strain imperiosus”.

Post COVID-19 invasive mucormycosis and actinomycosis co-infection: a case report

<p>Actinomyces are commensals of human oropharynx and actinomycosis is considered mainly as an endogenous infection that is triggered by a mucosal lesion. Typically, the disease presents as a slowly progressive painless indurated mass evolving into multiple abscesses with draining sinus tracts sometimes expressing a typical yellow exudate with characteristic sulfur granules. The gold standard of diagnosis is histological examination and bacterial culture of the tissue. Most isolates are susceptible to beta lactams and they are the treatment of choice along with surgical management with drainage of abscesses and excision of recalcitrant fibrotic lesions and debridement of necrotic bone tissue. Here we present a case of 37-year-old male patient who has developed severe COVID-19 infection following which he developed invasive mucormycosis followed by actinomycosis. We postulate that the lymphopenia and the use of immunosuppressants used in treatment of COVID-19 lead to mucormycosis and aggressive debridement used as a strategy in treatment of mucormycosis led to colonization of actinomyces leading to cervicofacial actinomycosis.</p>

Actynomicosis of the abdomen mimicking acute appendicitis

Bacteria of the genus Actinomyces are non-spore-forming filamentous, Microaerophilic or strict anaerobic, Gram-positive bacilli, mainly belonging to the human commensal flora of the oropharynx, gastrointestinal tract, and urogenital tract; Actynomicosis israelii is most frequently isolated in human infection by this bacteria (90% of the cases), and is a very rare, generally a polymicrobial granulomatous infection which affects the cervicofacial (55% of all cases), abdominopelvic (22%) and thoracic (15%) regions, causing formation of abscesses, woody fibrosis and sinus discharge of characteristic sulfur granules. We present the case of a 42 year old patient with no prior medical history who presented to the emergency room with acute onset abdominal pain in the lower right quadrant, leukocytosis and neutrophilia, as well as ultrasonographic images which suggested acute appendicitis, the patient underwent laparoscopic appendectomy and cultures of abscesses surrounding the appendix were positive for A. israelii, which was also isolated in the histopathological specimen. The patient underwent antimicrobial treatment with ampicilin-sulbactam for a three month period postoperatively.

“Holes” in the Jaw—A Report of Two Cases of Periapical Actinomycosis

Periapical actinomycosis is a relatively rare form of cervicofacial actinomycosis, which typically involves the periapical region with subsequent potential spread to the jaw bones. We hereby present two cases of periapical actinomycosis. Both patients presented with jaw pain and “holes” in their gum and lacked the characteristic clinical features commonly seen in cervicofacial actinomycosis such as jaw mass, draining ulcers, sinuses and fistulae. The first patient was an immunocompetent host with chronic stable medical conditions but with a rather bad dentition requiring multiple recent teeth extractions. The second patient was edentulous, had refractory multiple myeloma, was on low-dose chronic steroids and pomalidomide therapy and therefore relatively immunocompromised. Both cases of actinomycosis were diagnosed by jaw bone histopathology, which showed characteristic sulfur granules and embedded Actinomyces-like organisms. The two patients had excellent clinical response to six months of penicillin therapy without any need for surgical intervention. The cases remind clinicians of including actinomycosis in the differential diagnosis of periapical lesions and illustrates the possibility of achieving cure with non-surgical treatment.

Middle Ear Actinomycosis

Middle ear actinomycosis is an atypical and exceedingly rare anaerobic infection. The authors report a case of a 7-year-old girl with persistent right side otalgia, conductive hearing loss, and headache. Otoscopic findings included a thickened, intact, and bulging tympanic membrane. Computed tomography imaging revealed soft tissue density filling the middle ear with areas of bone erosion. Typical sulfur granules were found on surgical exploration. Actinomycosis was diagnosed by histopathological examination. Penicillin was prescribed for 5 weeks followed by oral amoxicillin for 6 months. Recovery was uneventful and with a 2-year follow-up, no recurrence or complications were observed.

Nitrate removal from aquaculture effluents using woodchip bioreactors improved by adding sulfur granules and crushed seashells

This study examined the effects on nitrate removal when adding sulfur granules and crushed seashells to a woodchip bioreactor treating aquaculture effluents. Using a central composite design, the two components were added at three levels (0.000, 0.125 and 0.250 m3/m3 bioreactor volume) to 13 laboratory-scale woodchip bioreactors, and a response surface method was applied to find and model the optimal mixture ratios with respect to reactor performance. Adding 0.125 m3/m3 sulfur granules improved the total N removal rate from 3.27 ± 0.38 to 8.12 ± 0.49 g N/m3/d compared to pure woodchips. Furthermore, the inclusion of crushed seashells together with sulfur granules helped to maintain the pH above 7.4 and prevent a production (i.e., release) of nitrite. According to the modeled response surfaces, a sulfur granule:crushed seashell:woodchip mixture ratio containing about 0.2 m3 sulfur granules and 0.1 m3 crushed seashells per m3 reactor volume would give the best results with respect to high N removal and minimal nitrite release. In conclusion, the study showed that N removal in woodchip bioreactors may be improved by adding sulfur granules and seashells, contributing to the optimization of woodchip performance in treating aquaculture effluents.

Omental actinomycosis imitating a foreign body infection

Actinomycosis is a rare chronic disease caused by a group of anaerobic Gram-positive bacteria that colonize the mouth, colon, and urogenital tract. Infection involving the cervicofacial area is the most common clinical presentation, followed by that of the pelvic and thoracic areas. The preoperative diagnosis of abdominal actinomycosis is difficult because the condition can be easily confused with malignancy, tuberculosis, or other inflammatory diseases. We report a case of omental actinomycosis mimicking a foreign body. Actinomycosis is diagnosed based on the histopathologic demonstration of sulfur granules in a tissue or organ that was surgically removed. Following confirmative diagnosis by surgical intervention, the patient was treated with oral doxycycline 100 mg twice daily for 6 months. A follow-up abdominopelvic computed tomography after 16 months showed no evidence of inflammation. Moreover, the patient no longer had disease-associated symptoms and exhibited normal laboratory findings.

Cytopathology of Hepatobiliary-Related Actinomycosis

Background: The clinical diagnosis of hepatobiliary-related actinomycosis can be challenging owing to its rarity and variable presentation. Moreover, actinomycotic pseudotumors may mimic malignancy and result in unnecessary surgical resection. Herein, we present the clinical and cytopathological features of 3 cases with hepatobiliary-related actinomycosis. Cases: The first patient was a 73-year-old man who presented with an exophytic liver lesion. The second patient was a 78-year-old woman who presented with a biliary stricture. The third patient was an 88-year-old woman with a right flank mass extending to the liver. The aspirate smears in these 3 cases demonstrated ‘cotton ball' clusters of filamentous microorganisms and abscesses. The cell blocks of 2 of the patients showed sulfur granules with peripheral filamentous microorganisms positive with a Gram stain but negative with an acid fast stain, consistent with Actinomyces species. All patients were elderly and shared a past surgical history of laparoscopic cholecystectomy. Conclusion: These cases demonstrate the complementary role of cytology in the diagnosis of hepatobiliary actinomycosis. A cytologic diagnosis of actinomycosis is minimally invasive and quick. It can prompt proper culture medium selection and avoid unnecessary or extensive surgery. Based on our experience, laparoscopic cholecystectomy may be a precipitating factor for the subsequent development of hepatobiliary-related actinomycosis.