The epidemiology, clinical presentation and treatment outcomes in CNS actinomycosis: a systematic review of reported cases.

BACKGROUND: CNS actinomycosis is a rare chronic suppurative infection with non-specific clinical features. Diagnosis is difficult due to its similarity to malignancy, nocardiosis and other granulomatous diseases. This systematic review aimed to evaluate the epidemiology, clinical characteristics, diagnostic modalities and treatment outcomes in CNS actinomycosis. METHODS: The major electronic databases (PubMed, Google Scholar, and Scopus) were searched for the literature review by using distinct keywords: "CNS" or "intracranial" or "brain abscess" or "meningitis" OR "spinal" OR "epidural abscess" and "actinomycosis." All cases with CNS actinomycosis reported between January 1988 to March 2022 were included. RESULTS: A total of 118 cases of CNS disease were included in the final analysis. The mean age of patients was 44 years, and a significant proportion was male (57%). Actinomycosis israelii was the most prevalent species (41.5%), followed by Actinomyces meyeri (22.6%). Disseminated disease was found in 19.5% of cases. Most commonly involved extra-CNS organs are lung (10.2%) and abdomen (5.1%). Brain abscess (55%) followed by leptomeningeal enhancement (22%) were the most common neuroimaging findings. Culture positivity was found in nearly half of the cases (53.4%). The overall case-fatality rate was 11%. Neurological sequelae were present in 22% of the patients. On multivariate analysis, patients who underwent surgery with antimicrobials had better survival (adjusted OR 0.14, 95% CI 0.04-0.28, p value 0.039) compared to those treated with antimicrobials alone. CONCLUSION: CNS actinomycosis carries significant morbidity and mortality despite its indolent nature. Early aggressive surgery, along with prolonged antimicrobial treatment is vital to improve outcomes.

Paediatric actinomycosis: A 16-year, single-institution retrospective review of cases.

AIM: Actinomycosis is a rare subacute to chronic granulomatous infection which can mimic other infectious or malignant diseases. This study examined the epidemiology and treatment outcome of actinomycosis in children. METHODS: A retrospective study on children admitted for actinomycosis in a tertiary paediatric hospital in Singapore, from January 2004 to December 2020. Clinical profile, therapeutic interventions and outcomes were examined. RESULTS: A total of 10 patients were identified; 7 were female. The median age at first presentation was 9.8 years (range 4.7-15.7). The most common presenting symptom was fever (n = 6, 60%), followed by facial or neck swelling (n = 3, 30%) and ear pain (n = 3, 30%). Actinomycosis occurred predominantly in the orocervicofacial region (n = 6, 60%). Four patients (40%) had preceding dental infections in the form of dental caries or gingivitis. One patient had poorly controlled insulin-dependent diabetes mellitus. Actinomycosis was confirmed via culture in four patients, histopathology in four patients and both methods in two patients. All except one patient (n = 9, 90%) underwent surgical procedures. All patients received ampicillin or amoxicillin/clavulanate or other beta-lactams, for a median duration of 6.5 months (range 1.5-14). Complications included osteomyelitis (n = 4, 40%), mastoiditis (n = 2, 20%), brain abscess (n = 1, 10%) and recurrent neck abscess (n = 1, 10%). There was no mortality and all patients achieved complete resolution. CONCLUSIONS: Paediatric actinomycosis was rare in our 16-year review, but had a high complication rate. It can occur in immunocompetent patients, and dental infection was the predominant risk factor identified. Prognosis was excellent after surgical intervention and appropriate antimicrobial therapy.

The Incidence and Risk Factors of Chronic Pulmonary Infection after Radiotherapy in Patients with Lung Cancer.

PURPOSE: This study aimed to investigate cumulative incidence and risk factors associated with chronic pulmonary infection (CPI) development after radiotherapy for lung cancer. Materials and Methods: We retrospectively analyzed 1,872 patients with lung cancer who received radiotherapy for lung cancer from 2010-2014, had a follow-up period of ≥ 3 months after radiotherapy, and did not have CPI at the time of radiotherapy. CPI was defined as pulmonary tuberculosis, non-tuberculous mycobacterial pulmonary disease, chronic pulmonary aspergillosis, or pulmonary actinomycosis. The cumulative incidence of CPI and overall survival (OS) were estimated using the Kaplan-Meier method, and a multivariable Cox proportional hazards analysis was performed to identify risk factors associated with CPI development. RESULTS: The median follow-up period was 2.3 years with OS rates of 55.6% and 37.6% at 2 and 5 years, respectively. CPI developed in 59 patients at a median of 1.8 years after radiotherapy, with cumulative incidence rates of 1.1%, 3.4%, 5.0%, and 6.8% at 1, 3, 5, and 7 years, respectively. A lower body mass index, interstitial lung disease, prior pulmonary tuberculosis, larger clinical target volume, history of lung cancer surgery or radiation pneumonitis, and use of inhaled corticosteroids were independent risk factors for CPI development. CONCLUSION: The long-term survival rate of lung cancer patients receiving radiotherapy was not low, but the cumulative incidence of CPI gradually increased to 6.8% at 7 years after radiotherapy. Therefore, close monitoring of CPI development is required in surviving patients with risk factors.

Infective endocarditis by Actinomyces species: a systematic review.

Actinomycosis, is a slowly progressive infection that may mimic malignancy due to the invasiveness of tissues and the ability to form sinus tracts. Infective Endocarditis (IE) is a rare disease with significant morbidity and mortality. Interestingly, even though there are scarce data of IE by Actinomyces spp. in the literature, a review adequately summarizing all available evidence on the topic in a systematic way is lacking. The aim of this study was to systematically review all cases of IE by Actinomyces spp. in the literature and describe the epidemiology, microbiology, clinical characteristics, treatment and outcomes of this infection. A systematic review of PubMed, Scopus and Cochrane library (through 19 August 2021) for studies providing epidemiological, clinical, microbiological as well as treatment data and outcomes of IE by Actinomyces spp. was performed. A total of 31 studies providing data for 31 patients were included. A prosthetic valve was present in 12.9%, while the most common microorganism was A. meyeri. Aortic valve was the most commonly infected intracardiac site, followed by the mitral valve. Diagnosis was most commonly performed with transesophageal echocardiography, while the diagnosis was made at autopsy in 16.1%. Penicillin, cephalosporins and aminopenicillins were the most commonly used antimicrobials. Clinical cure was noted in 80.6%, while mortality was 19.4%. Development of heart failure was associated with mortality by IE. This systematic review thoroughly describes IE by Actinomyces and provides information on epidemiology, clinical presentation, treatment and outcomes.

Clinical features of actinomycosis: A 20-year experience of a single institute in Southern China.

BACKGROUND: Actinomycosis is a rare indolent infectious disease with nonspecific clinical presentations that delay diagnosis. Although actinomycosis is thought to be more prevalent in developing countries, data from developing countries are scarce. This study aimed to profile actinomycosis in developing countries and identify how it differed from profiles of developed countries. METHODS: Patients fulfilling the inclusion criteria for actinomycosis from Nanfang Hospital in southern China between January 1999 and December 2018 were retrospectively analyzed. We described clinical characteristics, diagnostic procedures, differential diagnosis, and management of actinomycosis of clinical significance. RESULTS: Thirty­one patients were included in this study. The disease was diagnosed predominately in the orocervicofacial (n = 14), cardiothoracic (n = 11), abdominopelvic (n = 5), and soft tissue (n = 1) regions. Diagnosis was obtained by either histopathology (n = 29, 94%) or microbiology (n = 2, 6%). Only one-third of patients presented with general symptoms, such as fever and weight loss. Ten were lost during follow-up, and the median duration of antibiotic use was 93.5 days (interquartile range 28-300), whereas the median follow-up time was 34 months (interquartile range 9-132). Ten patients receiving complete resection of the lesion were cured without postoperative use of antibiotics. Only one patient relapsed during the follow-up period. CONCLUSIONS: Actinomycosis is a rare disease even in developing countries, and both misdiagnosis and missed diagnosis are common. Diagnosis was often delayed and was obtained postoperatively from histopathology in developing countries. Hence, clinicians should be aware of this disease in patients with high risk factors. In the future, specific molecular methods may help to improve early diagnosis and treatment.

Clinical aspects of abdominal actinomycosis: a systematic review.

BACKGROUND: Abdominal actinomycosis (AA) is a rare infection. The aim of this study was to summarize the evidence available on AA. METHODS: A systematic review was conducted. Data sources included Trip Database, BIREME, SciELO, Cochrane Library, WoS, MEDLINE, EMBASE, SCOPUS, IBECS and LILACS. Eligibility criteria included: studies related to surgically treated AA, in adult population, without language and sex restriction, published between 1966 and 2019. The following variables were analysed: publication year, age, sex, geographical origin, location of lesions, clinical manifestations, risk factors, species isolated and treatments used. RESULTS: A total of 1505 studies were initially identified. After scrutinizing titles and abstracts, and checking duplications, 221 articles including 406 subjects with AA were included. All were case reports or series. Mean age of subjects was 49.2 years and 56.2% were female. The highest proportion of articles was published between 2015 and 2019 (18.7%). Publications were predominantly from the USA (12.2%). Structures usually involved were abdominal wall, colon and appendix. The most common presentation was abdominal mass (39.2%). In 42.1% of patients, an associated factor was found, highlighting intrauterine devices (14.3%). The microbiology studies highlighted Actinomyces israelli. Morbidity, recurrence and verified mortality were 18.2%, 1.0% and 2.2%, respectively. Penicillin was the most used antibiotic. CONCLUSION: Evidence about AA is scarce and dispersed within a reduced range of articles and cases.

Actinomicosis renal en adolescente inmunocomprometido / Renal actinomycosis in immune compromised teenager

Fundamento: la actinomicosis es una enfermedad granulomatosa crónica poco común. El compromiso renal es raro y el diagnóstico suele ser posterior a la nefrectomía. Objetivo: presentar el caso de un adolescente con actinomicosis renal. Caso clínico:adolescente femenina, raza blanca, 13 años de edad, con antecedentes de asma bronquial e inmunocomprometida. Hace seis meses ingresó en el Hospital Pediátrico Eduardo Agramonte Piña de Camagüey debido a amigdalitis pultácea y se le indicó tratamiento antimicrobiano con una evolución favorable. Hace una semana comenzó con fiebre de 39 grados centígrados, vómitos, toma del estado general y dolor lumbar derecho por lo que reingresa para diagnóstico y tratamiento. Conclusiones: dado que la actinomicosis renal se presenta como una lesión sólida que invade estructuras vecinas es confundida con frecuencia con enfermedades neoplásicas. Menos del 10 porciento de los casos son diagnosticados antes de la cirugía, las pruebas complementarias son de escaso valor diagnóstico. El diagnóstico definitivo se basa en la identificación histológica o en cultivos en medios anaerobios del Actinomyces(AU)

Background: actinomycosis is a rare chronic granulomatous disease. Renal involvement is rare and the diagnosis is usually after nephrectomy. Objective:to present a case suffering from renal actinomycosis in a teenage patient. Clinical Case: caucasian, female, 13-years-old adolescent, who has a previous history of Bronchial Asthma and also immunocompromised. Six months ago she was admitted in the Pediatric Hospital Eduardo Agramonte Piña of Camagüey suffering from Tonsillitis and antimicrobial treatment was imposed with a favorable outcome. A week ago she started with 39 degrees fever, vomiting, general condition and right back lower pain. She was admitted in the Pediatric Hospital again to achieve a proper diagnosis and treatment. Conclusions: given that Renal Actinomycosis presents as a solid lesion that invades neighboring structures, the usual behavior is frequently confused with neoplastic conditions. Less than 10 percent of cases are diagnosed before surgery, with complementary tests of little diagnostic value. The definitive diagnosis is based on the histological identification or cultures in anaerobic media of Actinomyces(AU)

Actinomycosis: An infrequent disease in renal transplant recipients?

Actinomycosis is a rare and heterogeneous infection involving Gram-positive anaerobic bacteria, which are commensals in the oral cavity and digestive tract. Only four cases of actinomycosis in renal transplant recipients have been reported to date. We performed a retrospective study in French renal transplantation centers to collect data about actinomycosis, patients, and transplantation. Seven cases were reported between 2000 and 2017; mean age was 55.7 years, and prevalence of actinomycosis was 0.02%. Median time between transplantation and infection was 104 months (4-204 months). Locations of actinomycosis were cervicofacial (n = 2), pulmonary (n = 2), abdominopelvic (n = 2), or cutaneous (n = 1). Two patients (28.5%) had acute kidney injury. Diagnosis was made possible by microbiology (71%) or histopathology (filaments and sulfur granules) (14%) of the infection site. The suspected gate of entry for the infection was dental (57%), abdominal (28.5%) or through the sinuses (14%). All patients were treated with amoxicillin for 30-200 days (median duration of 115 days), and clavulanic acid was added for 28.5% of cases. Three patients (43%) required surgery. All patients, except one, recovered completely after a few months. Actinomycosis is a rare, slow, progressive disease in French renal transplant recipients. The location and clinical features of this infection are miscellaneous. Global and renal outcomes do not seem to be affected by actinomycosis.

Prevalence of Infectious Organisms Observed in Cervical Smears Between 1997-2014 at Mubarak Al-Kabeer Hospital, Kuwait.

OBJECTIVES: This study aimed to examine gynaecological infectious agents observed in conventional and modified Papanicolaou cervical smears (CS) at a tertiary care hospital in Kuwait. METHODS: This retrospective study analysed 121,443 satisfactory CS samples collected between 1997-2014 at the Mubarak Al-Kabeer Hospital, Kuwait. Conventional CS samples were obtained between 1997-2005, while modified CS were obtained between 2006-2014 following the introduction of ThinPrep® testing (Hologic Corp., Bedford, Massachusetts, USA). All samples were initially screened by cytoscreeners before being analysed by cytopathologists to determine the presence of specific infectious agents. RESULTS: Overall, 8,836 (7.28%) of the cervical samples had infectious agents; of these, 62.48% were conventional and 37.52% were modified CS samples. The most frequently observed infectious agents were Candida species (76.05%), Trichomonas vaginalis (9.72%), human papillomavirus (HPV; 9.3%), Actinomyces-like organisms (3.23%), Chlamydia trachomatis (1.27%) and the herpes simplex virus (HSV; 0.43%). There were significantly more cases of Candida species, HPV-associated changes, C. trachomatis, T. vaginalis and Actinomyces-like organisms detected in conventional compared to modified CS samples (P <0.050 each). However, there was no statistically significant difference in the frequency of HSV-associated changes (P = 0.938). The presence of two infectious agents in the same sample was identified in 0.87% of samples. CONCLUSION: Among CS samples collected during an 18-year period, Candida species were most frequently detected, followed by T. vaginalis and HPV. The identification of potential infectious agents is a valuable additional benefit of Papanicolaou smear testing.

Cervical precancerous changes and selected cervical microbial infections, Kiambu County, Kenya, 2014: a cross sectional study.

BACKGROUND: Cervical cancer is the predominant cancer among women in Kenya and second most common in women in developing regions. Population-based cytological screening and early treatment reduces morbidity and mortality associated with the cancer. We determined the occurrence of cervical precancerous changes and cervical microbial infections (Trichomonas vaginalis, Candida albicans, Neisseria gonorrhea and Actinomyces) among women attending Family Health Option Kenya (FHOK) clinic in Thika. METHODS: This was a hospital based cross sectional study among women attending reproductive health screening clinic from November 2013 to January 2014. Cervical Intraepithelial Neoplasia (CIN) I, II, III, cervical cancer and microbial infection (Actinomyces, Trichomonas vaginalis and Yeast cells) diagnosis was based on Pap smear screening test and High Vaginal Swab wet preparation microscopy. Neisseria gonorrhea was diagnosed through Gram staining. Socio-demographic and reproductive health data was collected using a structured questionnaire administered to the study participants and analyzed using Epi Info version 3.5.1. RESULTS: Of the 244 women screened, 238 (97.5%) presented with cervical inflammation, 80 (32.8%) cervical microbial infections and 12 (4.9%) cervical precancerous changes; 10 (83.3%) with CIN I and 2 (16.7%) CIN II. Of the 80 cervical microbial infections, 62 (77.5%) were yeast cell and 18 (22.5%) T. vaginalis. One thirty four (55%) participants had no history of Pap smear screening of which 84 (62.7%) were 20-40 years. Use of IUCDs (OR: 2.47, 95% CI 1.3-4.6) was associated with cervical inflammation. CONCLUSIONS: CIN I was the predominant cervical precancerous change. There is need to scale up cervical screening test to capture all categories of women.

Estimaciones de la incidencia de la actinomicosis en Colombia / Estimates of the incidence of actinomycosis in Colombia

No disponible

Primary pulmonary actinomycosis: a retrospective analysis of 145 cases in mainland China.

OBJECTIVE: To improve our understanding of pulmonary actinomycosis. METHODS: A retrospective analysis of 145 cases in mainland China was conducted. RESULTS: The male:female ratio was 2.7:1. Mean age at diagnosis was 48 years (± 12). Main symptoms were cough (87.6%), expectoration (40%), blood-stained sputum (37.2%), fever (26.9%), chest pain (24.8%) and haemoptysis (16.6%). Eighty-eight (60.7%) patients had no underlying disease. Only five patients received a correct initial diagnosis; 60 patients were misdiagnosed with lung cancer, followed by pulmonary tuberculosis (TB) and lung abscess. Most patients were diagnosed using surgical resection, transthoracic needle aspiration or flexible bronchoscopy. Sixty-seven patients received penicillin G, and one patient did not receive any antibiotics after surgery. The mean duration of treatment with antibiotics was 4.5 months (±3.7). Overall, 110 (75.9%) patients were fully cured, 4 died, 1 was lost to follow-up, and a record of the prognosis was not available for 30 patients. Mean duration of follow-up was 26 months (± 32). CONCLUSION: Pulmonary actinomycosis is a rare bacterial infection and is often misdiagnosed as lung cancer or pulmonary TB. The definitive diagnosis depends on pathology; sulfur granules are suggestive, but not specific. Penicillin G is the standard treatment. The optimal duration of antibiotic treatment merits further investigation.

Abdominal actinomycosis in the last 10 years and risk factors for appendiceal actinomycosis: review of the literature.

BACKGROUND/AIM: Actinomycosis is a granulomatous disease caused by filamentous, gram-positive, anaerobic bacteria. Actinomycetes are commensal inhabitants of the oral cavity and intestinal tract but acquire pathogenicity through invasion of breached or necrotic tissue.1397645907In abdominal actinomycosis (AA), the appendix and ileocecal region are usually involved. The aim of this study was to characterize patients diagnosed with AA and to establish the risk factors for appendiceal actinomycosis, including a short review of the literature. MATERIALS AND METHODS: We conducted a prospective cohort study of all patients diagnosed with AA in the University Hospital Marques de Valdecilla (Santander-Cantabria) from January 2003 to October 2013. We also conducted a short review of the literature. RESULTS: We characterized the epidemiological features of patients diagnosed with AA and risk factors for the involvement of the appendix, as most of the cases were misdiagnosed as appendicitis. Risk factors for appendiceal actinomycosis are no antecedents of carcinoma (P = 0.034) and previous incorrect diagnosis (P = 0.006). CONCLUSION: AA is a rare and chronic infection. It is only reported in case reports in the literature. We present the largest series of patients diagnosed with AA. Half of the patients had morbidities, mostly carcinoma, and penicillin was the preferred treatment. More studies are needed to characterize patients affected with AA and to establish the correct treatment.

Actinomyces meyeri, a Common Agent of Actinomycosis.

BACKGROUND: Actinomyces, particularly Actinomyces israelii, may cause indolent, persistent infections or represent normal mucosal flora, leading to management dilemmas. MATERIALS AND METHODS: Prompted by a refractory Actinomyces meyeri infection complicating AIDS, clinical data for all Actinomyces isolates at our hospital laboratory since 1998 were analyzed. RESULTS: A total of 140 cases had a positive result for Actinomyces cultures. Of 130 cases with adequate follow-up, 36 (28%) cases had end-organ or disseminated disease treated with prolonged antibiotics or surgery or both (Group 1). A. meyeri was more common than A. israelii (33% versus 8%; P < 0.05) in Group 1, particularly thoracic infections. Another 56 (43%) cases were considered local pathogens, treated with drainage only or short-course antibiotics (Group 2). Another 38 (29%) cases were deemed commensals (Group 3). Immunosuppression was less frequent in Group 1 versus Group 2 or 3 (P = 0.05) and human immunodeficiency virus or AIDS was uncommon. Foreign bodies or devices (Group 1 versus Group 2 or 3, P = 0.003) and alcoholism (Group 1 versus Group 2 or 3; P = 0.03) were associated with actinomycosis. Isolates from the central nervous system and musculoskeletal sites were more often treated as definitive disease; skin, abdominal or pelvic or single blood culture isolates were more likely commensals (all P < 0.05). Disease progression or recurrence did not occur in Groups 2 and 3, whereas Group 1 had complex and variable courses, including 2 deaths. CONCLUSIONS: In the absence of disseminated or end-organ disease, avoiding prolonged therapy for Actinomyces isolates was not associated with adverse outcomes. Alcoholism or foreign bodies were associated with actinomycosis. A. meyeri may be a more common cause of actinomycosis than previously recognized.

Clinical features of actinomycosis: A retrospective, multicenter study of 28 cases of miscellaneous presentations.

Actinomycosis is a rare heterogeneous anaerobic infection with misleading clinical presentations that delay diagnosis. A significant number of misdiagnosed cases have been reported in specific localizations, but studies including various forms of actinomycosis have rarely been published.We performed a multicenter retrospective chart review of laboratory-confirmed actinomycosis cases from January 2000 until January 2014. We described clinical characteristics, diagnostic procedures, differential diagnosis, and management of actinomycosis of clinical significance.Twenty-eight patients were included from 6 hospitals in France. Disease was diagnosed predominately in the abdomen/pelvis (n = 9), orocervicofacial (n = 5), cardiothoracic (n = 5), skeletal (n = 3), hematogenous (n = 3), soft tissue (n = 2), and intracranially (n = 1). Four patients (14%) were immunocompromised. In most cases (92 %), the diagnosis of actinomycosis was not suspected on admission, as clinical features were not specific. Diagnosis was obtained from either microbiology (50%, n = 14) or histopathology (42%, n = 12), or from both methods (7%, n = 2). Surgical biopsy was needed for definite diagnosis in 71% of cases (n = 20). Coinfection was found in 13 patients (46%), among which 3 patients were diagnosed from histologic criteria only. Two-thirds of patients were treated with amoxicillin. Median duration of antibiotics was 120 days (interquartile range 60-180), whereas the median follow-up time was 12 months (interquartile range 5.25-18). Two patients died.This study highlights the distinct and miscellaneous patterns of actinomycosis to prompt accurate diagnosis and earlier treatments, thus improving the outcome. Surgical biopsy should be performed when possible while raising histologist's and microbiologist's awareness of possible actinomycosis to enhance the chance of diagnosis and use specific molecular methods.

The role of bacteriological studies in the management of peritonsillar abscess.

OBJECTIVE: Since most patients with peritonsillar abscess (PTA) can be successfully treated with surgical drainage and empirical antibiotic therapy, routine bacteriologic studies for all patients with PTA may be unnecessary. This study tried to evaluate which patients with PTA should certainly undergo bacteriologic studies. METHODS: Hundred consecutive patients with PTA were treated and underwent culture tests of purulent contents obtained by surgical drainage between April 2008 and December 2013. RESULTS: In 62 of the 100 patients, 71 pathogenic bacteria were identified; 61 (86%) were Gram-positive cocci (GPC), 8 (11%) were Gram-negative rods (GNR), and 6 (8%) were anaerobes. Normal flora were isolated in 27 patients, and culture results were negative in 11 patients. Although not significant, primary (without prior antibiotic therapy) case (odds ratio (OR)=2.19; 95% CI, 0.95-5.05) and laryngeal edema (OR=2.04; 95% CI, 0.82-5.03) showed a tendency of associations with detection of pathogenic bacteria. After taking into account interactions between smoking habit and laryngeal edema, the covariate-adjusted OR for non-smokers with laryngeal edema was significant and showed a strong relationship (OR=7.43; 95% confidence interval, 1.05-52.73) compared to non-smokers without laryngeal edema. CONCLUSION: Although empirical antibiotic therapy was effective for most of the PTA patients, bacteriologic studies might be indispensable for the patients with laryngeal edema considering the failure of the first treatments. Particularly, the culture tests may be useful for non-smokers with laryngeal edema.

Species-Level Identification of Actinomyces Isolates Causing Invasive Infections: Multiyear Comparison of Vitek MS (Matrix-Assisted Laser Desorption Ionization-Time of Flight Mass Spectrometry) to Partial Sequencing of the 16S rRNA Gene.

Actinomyces species are uncommon but important causes of invasive infections. The ability of our regional clinical microbiology laboratory to report species-level identification of Actinomyces relied on molecular identification by partial sequencing of the 16S ribosomal gene prior to the implementation of the Vitek MS (matrix-assisted laser desorption ionization-time of flight mass spectrometry [MALDI-TOF MS]) system. We compared the use of the Vitek MS to that of 16S rRNA gene sequencing for reliable species-level identification of invasive infections caused by Actinomyces spp. because limited data had been published for this important genera. A total of 115 cases of Actinomyces spp., either alone or as part of a polymicrobial infection, were diagnosed between 2011 and 2014. Actinomyces spp. were considered the principal pathogen in bloodstream infections (n = 17, 15%), in skin and soft tissue abscesses (n = 25, 22%), and in pulmonary (n = 26, 23%), bone (n = 27, 23%), intraabdominal (n = 16, 14%), and central nervous system (n = 4, 3%) infections. Compared to sequencing and identification from the SmartGene Integrated Database Network System (IDNS), Vitek MS identified 47/115 (41%) isolates to the correct species and 10 (9%) isolates to the correct genus. However, the Vitek MS was unable to provide identification for 43 (37%) isolates while 15 (13%) had discordant results. Phylogenetic analyses of the 16S rRNA sequences demonstrate high diversity in recovered Actinomyces spp. and provide additional information to compare/confirm discordant identifications between MALDI-TOF and 16S rRNA gene sequences. This study highlights the diversity of clinically relevant Actinomyces spp. and provides an important typing comparison. Based on our analysis, 16S rRNA gene sequencing should be used to rapidly identify Actinomyces spp. until MALDI-TOF databases are optimized.

Actinomicosis Torácica / Thoracic Actinomycosis

La actinomicosis torácica es una infección bacteriana lentamente progresiva, producida por bacterias grampositivas anaerobias o microaerófilas que colonizan la orofaringe y el tracto gastrointestinal. Su baja frecuencia en la actualidad y sus distintas ubicaciones anatómicas constituyen un desafío diagnóstico para las distintas especialidades de la medicina. En este trabajo se presenta el caso de un paciente de 44 años de edad, con antecedentes de salud, que ingresa en el Hospital Regional de Zacapa en Guatemala por fístulas en hemitórax izquierdo y neumonía en vértice homolateral de 6 meses de evolución, interpretado inicialmente como tuberculosis pulmonar. Luego de exámenes complementarios y otros como Radiografía de Tórax, Baciloscopia, VIH y Cultivo de secreción de la lesión, se realizó Biopsia de la lesión, observándose gránulos de azufre con abundante tejido de granulación y celularidad compatible con Actinomyces israelii(AU)

Thoracic actinomycosis is a slowly progressing bacterial infection caused by gram-positive anaerobic or microaerophilic bacteria that colonize oropharynx and gastrointestinal tract. Its low frequency at present and its different anatomical locations are a diagnostic challenge for various medical specialties. The case of a 44-year-old man with health history is presented here. This patient was admitted at Zacapa Regional Hospital in Guatemala due to a fistula in left chest and pneumonia in ipsilateral vertex for six months, initially it was interpreted as pulmonary tuberculosis. After further examination and studies such as chest x-rays, smear, HIV and culture of discharge of the injury, this patient underwent a biopsy of the lesion, showing sulfur granules and abundant granulation tissue and Actinomyces israelii compatible cellularity(AU)