Cervical lymphadenitis from Mycobacterium avium complex.

We present an instructive case of cervical lymphadenitis in a young man without a history of HIV infection. The patient developed spontaneous left-sided neck swelling that progressed over 4 months. CT imaging demonstrated a necrotic left-sided neck mass within the cervical lymph node chain. He was initially prescribed azithromycin and rifampin for presumed cat scratch disease with improvement but incomplete resolution of symptoms. Blood cultures ordered 2 months later grew Mycobacterium avium complex (MAC) and the patient had an excellent clinical response to MAC therapy. Here, we review the case, including presentation and management, and describe the implications for the immune status of the host and long-term considerations for treatment.

Extensive Bilateral Cervicofacial Lymphadenitis Caused by Atypical Mycobacterium.

Non-tuberculous mycobacterial (NTM) lymphadenitis typically presents as a unilateral, non-tender, slowly enlarging cervical, submandibular, or pre-auricular lymph node in children. Disseminated NTM infection is most often seen in immunocompromised children. Here, we present an unusual case of extensive bilateral cervical and retropharyngeal lymphadenitis caused by Mycobacterium Avium Complex (MAC) in an ostensibly immunocompetent pediatric patient.

Comparison of treatment modalities for non-tuberculous mycobacterial cervicofacial lymphadenitis in children.

PURPOSE: We aim to compare the different treatment modalities of non-tuberculous cervicofacial lymphadenitis in children, by means of a retrospective study conducted in the University Hospitals of Leuven of patients treated between 2012 and 2022. METHODS: For this retrospective cohort study, data were collected and pseudonimised from 52 patients with non-tuberculous cervicofacial lymphadenitis, who were treated in our hospital between January 2012 and December 2022, either conservatively, antibiotically, surgically, or with a combination of these options. We only included patients who were considered immunocompetent. All of the included patients were below 10 years at time of treatment. We collected data regarding time to resolution and adverse effects, i.e., skin discoloration, excessive scar formation, fistula formation, persistence of adenopathies after treatment, need for additional treatment, facial nerve paresis/paralysis, or systemic side-effects due to antibiotic treatment. RESULTS: The mean time to resolution (in days) when looking at primary treatments, was shortest in partial excisions (16), followed by complete excisions (19), antibiotic therapy (129), incision and drainage (153), curettage (240), and finally conservative management (280). Taking into account isolated treatments (i.e., both primary and adjuvant), we also observed consistently faster time to resolution in surgical and antibiotic treatments when compared to conservative treatment. Antibiotic therapy (p = 0.003), incision and drainage (p = 0,004) were associated with a significantly higher need for adjuvant treatment. Curettage was associated with a higher incidence of fistula formation (p = 0,006) and higher number of adjuvant treatments (p = 0,002). CONCLUSIONS: This study shows a faster resolution of nontuberculous mycobacterial cervicofacial lymphadenitis in children when treated surgically, more specifically when treated with partial or complete lymph node excision. Antibiotic treatment also leads to faster resolution than conservative management. There was a low rate of complications, and no permanent facial nerve damage was reported.

Current management of cervicofacial nontuberculous mycobacterial infections in the pediatric population.

PURPOSE OF REVIEW: The purpose of this review is to analyze and consolidate recently published literature to provide updated guidelines on the diagnosis and management of nontuberculous mycobacterial lymphadenitis (NTM LAD) in the pediatric population and to suggest areas of further research. RECENT FINDINGS: Diagnosis of NTM LAD relies on a detailed clinical history, physical examination, laboratory tests, and imaging techniques. Treatment strategies vary widely, with a shift towards complete surgical excision being observed due to its higher cure rate, improved aesthetic outcomes, and lower recurrence rates. However, patient-specific factors must be considered. The role of genetic factors, such as Mendelian susceptibility to mycobacterial disease (MSMD), is being increasingly recognized and could lead to targeted therapies. SUMMARY: Despite strides in the understanding and management of NTM LAD, substantial gaps remain in key areas such as the role of diagnostic imaging, optimal treatment parameters, postoperative care, and surveillance strategies. In this article, we explain our approach to NTM using the most relevant evidence-based medicine while offering directions for future work.

Non-Tuberculous Mycobacterial Cervicofacial Lymphadenitis in Children-10-Year Experience in a Tertiary Pediatric Center.

BACKGROUND: Lymphadenitis is the most common manifestation of non-tuberculous mycobacteria (NTM) infection in children. We describe the epidemiology and clinical characteristics of NTM lymphadenitis, determine diagnostic yield from tissue sampling, and review management and outcomes. METHODS: This was a 10-year retrospective review of children aged 0-16 years diagnosed with NTM cervicofacial lymphadenitis who were seen in a pediatric infectious disease clinic in a tertiary public hospital. Data relating to patient demographics, clinical features, surgical and antimicrobial treatment, complications, and outcomes were retrieved from patients' electronic medical records and analyzed. RESULTS: There were 48 episodes of NTM cervicofacial lymphadenitis in 45 children (17 males and 28 females). Of these episodes, 43.7% manifested as a unilateral single node, mostly parotid (39.6%) and submandibular (29.2%). All patients underwent diagnostic fine-needle aspiration or surgery. Surgical excision more frequently yielded positive histological findings (P = .016). NTM was identified in 22/48 episodes (45.8%) via culture or molecular sequencing. Mycobacterium abscessus was most commonly found (47.8%). Thirty-eight children (79.2%) received antibiotics. Outcomes in 43 episodes revealed full resolution in 69.8%, while 25.6% had de novo disease and 4.6% experienced recurrence at the same site. Overlying skin changes and multiple or bilateral nodal diseases were significantly associated with de novo disease or recurrence (P = .034 and .084, respectively). Complications occurred in 11/70 (15.7%) procedures. Antibiotic-associated adverse effects occurred in 14/38 (36.8%) episodes. CONCLUSIONS: NTM lymphadenitis remains a challenging condition. More aggressive management with surgical excision and antibiotics is recommended for those with overlying skin changes and extensive nodal disease.

Cervical lymphadenitis caused by Mycobacterium avium in a patient treated with Janus kinase inhibitors.

A woman diagnosed with rheumatoid arthritis and treated with Janus kinase (JAK) inhibitors presented with a gradually enlarging bilateral submandibular lymph nodes swelling that had lasted several weeks. A lymph node biopsy showed epithelioid granulomatous lymphadenitis with caseous necrosis. Mycobacteria grew in acid-fast bacteria culture and were identified as Mycobacterium avium by polymerase chain reaction. The patient was diagnosed with cervical lymphadenitis caused by M. avium. A computed tomography scan showed no evidence of a mass or infection at other sites, including the lungs; therefore, the mass was excised without any antimicrobial treatments. Her neck mass had not recurred at 9 months after the excision. JAK inhibitors have emerged as an important new class of oral therapy for rheumatoid arthritis and other diseases. Physicians should be aware of the relatively rare complications, such as cervical lymphadenitis caused by nontuberculous mycobacteria, when using JAK inhibitors.

A serum NMR metabolomic analysis of the Corynebacterium pseudotuberculosis infection in goats.

Caseous lymphadenitis (CLA), an infectious disease caused by Corynebacterium pseudotuberculosis in small ruminants, is highly prevalent worldwide. Economic losses have already been associated with the disease, and little is known about the host-pathogen relationship associated with the disease. The present study aimed to perform a metabolomic study of the C. pseudotuberculosis infection in goats. Serum samples were collected from a herd of 173 goats. The animals were classified as controls (not infected), asymptomatic (seropositives but without detectable CLA clinical signs), and symptomatic (seropositive animals presenting CLA lesions), according to microbiological isolation and immunodiagnosis. The serum samples were analyzed using nuclear magnetic resonance (1H-NMR), nuclear Overhauser effect spectroscopy (NOESY), and Carr-Purcell-Meiboom-Gill (CPMG) sequences. The NMR data were analyzed using chemometrics, and principal component analysis (PCA) and partial least square discriminant analysis (PLS-DA) were performed to discover specific biomarkers responsible for discrimination between the groups. A high dissemination of the infection by C. pseudotuberculosis was observed, being 74.57% asymptomatic and 11.56% symptomatic. In the evaluation of 62 serum samples by NMR, the techniques were satisfactory in the discrimination of the groups, being also complementary and mutually confirming, demonstrating possible biomarkers for the infection by the bacterium. Twenty metabolites of interest were identified by NOESY and 29 by CPMG, such as tryptophan, polyunsaturated fatty acids, formic acid, NAD+, and 3-hydroxybutyrate, opening promising possibilities for the use of these results in new therapeutic, immunodiagnosis, and immunoprophylactic tools, as well as for studies of the immune response against C. pseudotuberculosis. KEY POINTS: • Sixty-two samples from healthy, CLA asymptomatic, and symptomatic goats were screened • Twenty metabolites of interest were identified by NOESY and 29 by CPMG • 1H-NMR NOESY and CPMG were complementary and mutually confirming.

Acute bacterial lymphadenitis in children: a retrospective, cross-sectional study.

Acute bacterial lymphadenitis is a common childhood condition, yet there remains considerable variability in antibiotic treatment choice, particularly in settings with low prevalence of methicillin-resistant Staphylococcus aureus such as Europe and Australasia. This retrospective cross-sectional study reviewed children presenting with acute bacterial lymphadenitis to a tertiary paediatric hospital in Australia between 1 October 2018 and 30 September 2020. Treatment approaches were analysed with respect to children with complicated versus uncomplicated disease. A total of 148 children were included in the study, encompassing 25 patients with complicated disease and 123 with uncomplicated lymphadenitis, as defined by the presence or absence of an associated abscess or collection. In culture-positive cases, methicillin-susceptible S. aureus (49%) and Group A Streptococcus (43%) predominated, while methicillin-resistant S. aureus was seen in a minority of cases (6%). Children with complicated disease generally presented later and had a prolonged length of stay, longer durations of antibiotics, and higher frequency of surgical intervention. Beta-lactam therapy (predominantly flucloxacillin or first-generation cephalosporins) formed the mainstay of therapy for uncomplicated disease, while treatment of complicated disease was more variable with higher rates of clindamycin use.    Conclusion: Uncomplicated lymphadenitis can be managed with narrow-spectrum beta-lactam therapy (such as flucloxacillin) with low rates of relapse or complications. In complicated disease, early imaging, prompt surgical intervention, and infectious diseases consultation are recommended to guide antibiotic therapy. Prospective randomised trials are needed to guide optimal antibiotic choice and duration in children presenting with acute bacterial lymphadenitis, particularly in association with abscess formation, and to promote uniformity in treatment approaches. What is Known: • Acute bacterial lymphadenitis is a common childhood infection. • Antibiotic prescribing practices are highly variable in bacterial lymphadenitis. What is New: • Uncomplicated bacterial lymphadenitis in children can be managed with single agent narrow-spectrum beta-lactam therapy in low-MRSA prevalence settings. • Further trials are needed to ascertain optimal treatment duration and the role of clindamycin in complicated disease.

International Pediatric Otolaryngology Group: Consensus guidelines on the diagnosis and management of non-tuberculous mycobacterial cervicofacial lymphadenitis.

INTRODUCTION: Non-tuberculous mycobacterial (NTM) infection commonly manifests as subacute or chronic cervicofacial lymphadenitis in immunocompetent children. The optimal management of this pathology remains controversial. OBJECTIVES: This international consensus guideline aims to understand the practice patterns for NTM cervicofacial lymphadenitis and to address the primary diagnostic and management challenges. METHODS: A modified three-iterative Delphi method was used to establish expert recommendations on the diagnostic considerations, expectant or medical management, and operative considerations. The recommendations herein are derived from current expert consensus and critical review of the literature. SETTING: Multinational, multi-institutional, tertiary pediatric hospitals. RESULTS: Consensus recommendations include diagnostic work-up, goals of treatment and management options including surgery, prolonged antibiotic therapy and observation. CONCLUSION: The recommendations formulated in this International Pediatric Otolaryngology Group (IPOG) consensus statement on the diagnosis and management of patients with NTM lymphadenitis are aimed at improving patient care and promoting future hypothesis generation.

Long-Term Esthetic Outcome of Different Treatment Modalities for Nontuberculous Mycobacterial Cervicofacial Lymphadenitis.

BACKGROUND: Nontuberculous mycobacterial (NTM) cervicofacial lymphadenitis is a rare infection which almost exclusively occurs in children, most commonly children 0-5 years old. It can leave scars in highly visible areas. The present study aimed to evaluate the long-term esthetic outcome of different treatment modalities for NTM cervicofacial lymphadenitis. METHODS: This retrospective cohort study included 92 participants with a history of bacteriologically proven NTM cervicofacial lymphadenitis. All patients were diagnosed at least 10 years prior and were aged >12 years upon enrollment. Based on standardized photographs, the scars were assessed by subjects with the Patient Scar Assessment Scale, and by five independent observers with the revised and weighted Observer Scar Assessment Scale. RESULTS: The mean age at initial presentation was 3,9 years and the mean follow-up time was 15.24 years. Initial treatments included surgical treatment (n = 53), antibiotic treatment (n = 29) and watchful waiting (n = 10). Subsequent surgery was performed in two patients, due to a recurrence after initial surgical treatment, and in 10 patients initially treated with antibiotic treatment or watchful waiting. Esthetic outcomes were statistically significantly better with initial surgery, compared to initial non-surgical treatment, based on patient scores of scar thickness, and based on observer scores of scar thickness, surface appearance, general appearance and the revised and weighted sum score of all assessment items. CONCLUSIONS: The long-term esthetic outcome of surgical treatment was superior to non-surgical treatment. These findings could facilitate the process of shared decision making. LEVEL OF EVIDENCE: Level III.

Microbiology Culture Results and Antibiotic Prescribing in Pediatric Patients With Lymphadenitis.

BACKGROUND: Bacterial lymphadenitis is a common reason for antibiotic treatment and hospitalization in children. The literature available addressing the bacterial etiology of lymphadenitis recommends the use of narrow-spectrum agents to cover common pathogens. We suspect that patients at our institution receive unnecessarily broad-spectrum antimicrobial agents. The primary objective of this study was to characterize the microbiology and antibiotic use in lymphadenitis patients. METHODS: Retrospective review of children admitted over a 10-year period with an International Classification of Diseases Ninth or Tenth Edition code for lymphadenitis. Patients were included if they were <18 years old, admitted to the inpatient ward, and had intraoperative lymph node cultures collected. RESULTS: A total of 131 patients admitted with lymphadenitis had lymph node cultures collected and were included. Seventy-two (72/131; 55%) patients had positive lymph node culture results with pathogenic bacteria. The predominant pathogens were Staphylococcus aureus (56/72; 77.8%) and Streptococcus pyogenes (10/72; 13.9%). The most common inpatient empirical regimen was ampicillin-sulbactam. Of the 72 patients with typical pathogens identified, 80.6% were sensitive to a first-generation cephalosporin, whereas 86.1% were sensitive to a ß-lactam/ß-lactamase inhibitor. CONCLUSION: Patients presenting to our institution with acute bacterial lymphadenitis were predominantly found to have methicillin-susceptible S. aureus lymphadenitis that could be empirically treated with cefazolin. At our institution, there is little advantage to the most commonly used broad-spectrum agent, ampicillin-sulbactam.

Potential in vitro action of an adenosine analog and synergism with penicillin against Corynebacterium pseudotuberculosis.

Caseous lymphadenitis is a well-known disease caused by Corynebacterium pseudotuberculosis affecting small ruminants with small significance to human health because of its minor zoonotic potential. In both cases, few treatment options are available and conventional antimicrobial therapy is commonly refractory due to development of pyogranulomatous reactions, bringing great interest in discovering novel therapeutics for more suitable approaches. Dideoxynucleotides presented antibacterial action against various bacteria but were never described for C. pseudotuberculosis. Hypothesizing the antimicrobial action of 2',3'-dideoxiadenosine (ddATP) against C. pseudotuberculosis, we performed for the first time an investigation of its minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) in the ATCC® 19,410 strain and a well-characterized clinical isolate of C. pseudotuberculosis. We also assessed potential synergism with penicillin. ddATP showed a growth delay effect for C. pseudotuberculosis at 2 µmol/mL and a MIC and MBC of 4 µmol/mL against the ATCC® 19,410 strain, but not for the clinical strain. An antimicrobial effect was observed when using concentrations lower than the MIC of ddATP associated with penicillin for both strains tested. Our data suggest the potential of nucleotide analogs, especially adenosine, and its combination with penicillin, as a possible novel treatment for C. pseudotuberculosis-induced infections, and contributes with knowledge regarding alternative drugs to treat C. pseudotuberculosis infections.

Linfadenitis por Mycobacterium lentiflavum / Lymphadenitis caused by Mycobacterium lentiflavum

La linfadenitis cervical es la infección por micobacterias no tuberculosas (MNT) más frecuente en niños inmunocompetentes menores de 5 años. La mayoría de los casos a nivel mundial se debe a Mycobacterium avium complex (MAC). Mycobacterium lentiflavum (M. lentiflavum) se ha considerado una causa rara de MNT causante de linfadenitis. Presentamos dos casos de linfadenitis cervical y preauricular atendidos en un centro de salud de Madrid durante los años 2019-2020, que persisten a pesar de tratamiento antibiótico. Se realizaron test sanguíneos, serología, así como radiografía de tórax y prueba de tuberculina. Con la sospecha diagnóstica de MNT, los pacientes fueron derivados a un hospital terciario, donde se aisló M. lentiflavum. Aunque la actual evidencia acerca del tratamiento para la resolución de la linfadenitis es la escisión quirúrgica completa, en este caso fue descartada por la localización de los nódulos y el riesgo de dañar el nervio facial y la glándula parótida. Debido a que M. lentiflavum es resistente a la mayoría de los fármacos antituberculosos, se decidió, de acuerdo con los padres, un tratamiento conservador. Concluimos que M. lentiflavum debe ser considerado un importante patógeno emergente causante de linfadenitis y debe sospecharse en un paciente con una única linfadenitis cervical o preauricular que persiste a pesar de tratamiento antibiótico (AU)

Cervical lymphadenitis is the most common infection caused by non-tuberculous mycobacteria (NTM) in immuno-competent children under 5 years. Most cases of NTM associated cervical lymphadenitis worldwide are caused by Mycobacterium avium complex (MAC). Mycobacterium lentiflavum (M. lentiflavum) has been considered a rare cause of NTM associated lymphadenitis. We present two case reports of cervical and pre-auricular lymphadenitis managed in primary care in the Region of Madrid (Spain), between 2019-2020, that persisted despite antibiotic treatment. Routine blood tests, chest x-ray and tuberculin skin test were performed. As NTM was suspected, patients were referred to a tertiary hospital, where they underwent ultrasound guided aspiration, which cultured M. lentiflavum. Although, the first line treatment for NTM lymphadenitis is complete surgical excision, in these cases the proximity of the lymph nodes to the facial nerve and parotid gland meant this was not an option. Instead, a conservative approach of watch-and-wait was chosen in collaboration with the parents, as M. lentiflavum is resistant to most antituberculosis drugs. We conclude that M. lentiflavum should be considered as an important emergent pathogen causing cervical lymphadenitis, especially in cases with a single cervical or pre-auricular lymphadenitis resistant to antibiotic treatment. (AU)

Purulent lymphadenitis due to Halomonas hamiltonii: a case report.

Halomonas hamiltonii is a gram-negative rod bacterium isolated from highly saline environments. H. hamiltonii has rarely been reported as a human pathogen. Herein, we present the first case report of a purulent lymphadenitis caused by H. hamiltonii worldwide. The patient was a previously healthy girl aged 1 year who was referred to our hospital for left axillary lymphadenitis. Although oral amoxicillin was administered, lymphadenitis did not improve, and an abscess developed. After incision and drainage, the abscess was reduced. No recurrence of lymphadenitis was observed. The pus culture was negative. However, the 16S ribosomal DNA was amplified by the melting temperature mapping method. The amplified 16S ribosomal DNA sequence revealed 99.7% identity of H. hamiltonii. To the best of our knowledge, this is the first case of H. hamiltonii infection in a lymph node. This pathogen should be considered when diagnosing purulent lymphadenitis in healthy patients with lymphadenopathy of unknown origin.

Assessment of rSodC, rPknG, rNanH, and rSpaC as Antigens for Diagnostic Tools Against Caseous Lymphadenitis.

Corynebacterium pseudotuberculosis is a bacillus that causes caseous lymphadenitis in small ruminants, leading to great losses to rural producers; thus, an efficient diagnosis is necessary for using disease control measures. This study aimed to evaluate the antigenic potential of four C. pseudotuberculosis recombinant proteins (rSodC, rPknG, rNanH, and rSpaC) against sera of goat and sheep experimentally infected with one of three different C. pseudotuberculosis strains. Goats were infected with CAP76 or CAP21 strain (n = 10), sheep with VD57 strain (n = 6), and a group of not-infected animals (goats and sheep) were kept as a healthy control (healthy n = 12). Sera were collected at 0, 14, 60, 90, 180, or 190 days after inoculation for antigenicity testing using Western blotting and enzyme-linked immunosorbent assay (ELISA) techniques. Cross-reactivity tests with recombinant proteins were performed in goat serum experimentally vaccinated with Nocardia sp. or Rhodococcus equi bacterin. The rSodC protein showed discriminatory antigenic reactivity with a statistically significant difference against three different C. pseudotuberculosis strains evaluated in goats and sheep samples, while rPknG showed statistical significance only against two C. pseudotuberculosis strains evaluated in goats. rSodC was proved to be a strong candidate as a tool for diagnosis of C. pseudotuberculosis infection, once it was able to recognize antibodies against all strains evaluated in goats and sheep.

[Clinicopathological Characteristics of Lymphadenitis Caused by Talaromyces marneffei Diagnosed by Core Needle Biopsy].

Objective To analyze the clinicopathological characteristics of lymphadenitis caused by Talaromyces marneffei (TM).Method s The clinical data,pathological features,pathogen examination,and treatment of 15 cases of TM-caused lymphadenitis were analyzed retrospectively.Results The 15 cases included 14 males and 1 females,who were aged 26-67 years,with an average age of (49.1±11.87) years.The 15 cases,including 13 cases of acquired immunodeficiency syndrome and 2 cases of diabetes mellitus,were accompanied by superficial lymph node enlargement in the neck and supraclavicular,axillary,and inguinal regions.The structure of cord-like lymph node tissue punctured by thick needle was completely or partially replaced by inflammatory lesions. Under microscope,8 cases showed mainly diffuse infiltration of phagocytes with pathogens;5 cases presented mainly extensive coagulation necrosis with a small amount of pathogens and nuclear debris;2 cases were characterized by small nodular hyperplasia of fibroblasts,formation of granulomatous structure,and scattered distribution of a few multinucleated giant cells.The pathogens were relatively consistent in size and shape,which were round,oval or sausage-shaped and clustered like mulberry.Diastase periodic acid-Schiff staining and hexamine silver staining highlighted the bacterial structure with transverse septum.TM growth was detected in the blood,alveolar lavage fluid,sputum or lymph node extract fungal culture of the 15 patients.Owing to the adequate antifungal treatment in time,these 15 patients were discharged after their conditions were improved.Conclusion Lymphadenitis is one of the major manifestations of the systemic invasion of TM at the late stage,which is tended to be misdiagnosed.Through core needle biopsy of lymph node,it can be diagnosed as soon as possible to avoid delayed treatment and improve the cure rate.

A case of a 4-year-old boy with difficult-to-diagnose skin infection with nontuberculous mycobacteria.

Nontuberculous mycobacteria infections have become increasingly common in recent years and have even been confirmed in children. In addition to other organs, they can even affect the skin; nevertheless, in children lymphadenitis is the most common manifestation of the infection. The diagnosis of mycobacterial skin infection is based on patient history, clinical picture, histopathological changes, and tuberculin test result. Evidence of the causative agent in the lesion is confirmed with cultivation and PCR, two of the main tests that help determine the type of the causative mycobacteria. Here we report the case of a 4-year-old boy that presented with a few pink-to-livid papules and one plaque with a central crust on the skin of the left knee and an enlarged popliteal lymph node, highly suspicious of nontuberculous mycobacteria infection. Among the laboratory results, only a positive QuantiFERON and Mantoux test stood out. In addition, in the histopathological report, superficial and deep inflammatory elements were described, which could be due to an infection with nontuberculous mycobacteria. Despite negative cultivation and PCR, in agreement with a pediatric pulmonologist we decided to introduce antibiotic therapy for 6 months. Treatment was successful, we achieved regression of the skin lesions, and lymphadenitis was no longer present.

Chemokine production induced by Corynebacterium pseudotuberculosis in a murine model.

Corynebacterium pseudotuberculosis is the etiological agent of caseous lymphadenitis. The main clinical sign of this disease is the development of granulomas, especially in small ruminants; however, the pathways that are involved in the formation and maintenance of these granulomas are unknown. Cytokines and chemokines are responsible for the migration of immune cells to specific sites and tissues; therefore, it is possible that chemokines participate in abscess formation. This study aimed to evaluate the induction of chemokine production by two C. pseudotuberculosis strains in a murine model. A highly pathogenic (VD57) and an attenuated (T1) strain of C. pseudotuberculosis, as well as somatic and secreted antigens derived from these strains, was used to stimulate murine splenocytes. Then, the concentrations of the chemokines CCL-2, CCL-3, CCL-4, and CCL-5 and the cytokines IL-1 and TNF were measured in the culture supernatants. The VD57 strain had a higher ability to stimulate the production of chemokines when compared to T1 strain, especially in the early stages of stimulation, which can have an impact on granuloma formation. The T1 lysate antigen was able to stimulate most of the chemokines studied herein when compared to the other antigenic fractions of both strains. These results indicate that C. pseudotuberculosis is a chemokine production inducer, and the bacterial strains differ in their induction pattern, a situation that can be related to the specific behavior of each strain.