Acid-fast bacteria as causative agents of skin and soft tissue infections: case presentations and literature review

ABSTRACT Acid-fast bacteria can be implicated in skin and soft tissue infections. Diagnostic identification can be challenging or not feasible by routine laboratory techniques, especially if there is no access to the Matrix Assisted Laser Desorption Ionization Time of Flight Mass Spectrometry (MALDI-TOF MS) technology. Here, we present two cases of skin and soft tissue infections caused by two different acid-fast bacteria, Nocardia brasiliensis and Mycobacterium marinum. They both grew on Löwenstein-Jensen medium, Sabouraud agar medium and blood agar medium. Both bacteria appeared acid-fast by Ziehl-Neelsen stain and Gram-positive by Gram stain. The identification was performed by MALDI-TOF MS and gene analysis. N. brasiliensis and nontuberculous mycobacterium M. marinum represent rare pathogens that cause severe skin and soft tissue infections. Failure to identify the causative agent and subsequent inappropriate or inadequate treatment may lead to severe complications or even disseminated disease, especially in immunocompromised individuals.

Gallbladder tuberculosis: A rare case report with review of literature

Gallbladder tuberculosis (TB) is a rare disease, and it might be challenging to distinguish it from gallbladder cancer on clinical history and radiology. It frequently mimics carcinoma in patients who initially appear with a gallbladder mass. Gallbladder TB is only identified after histology of the resected specimen since radiography lacks pathognomic characteristics. Here, we describe a unique case of gallbladder TB that was incidentally identified when a 49-year-old lady was being evaluated for suspected gallbladder cancer. Histology of the gallbladder exhibits necrotizing granulomatous inflammation with the presence of numerous pink-colored, curved, and beaded acid-fast bacilli that were recognized on the Ziehl-Neelsen stain.

Comparative Study of Conventional Ziehl Neelsen and Modified Bleach Method of Ziehl Neelsen with CBNAAT in the Diagnosis of Tuberculous Lymphadenitis

Tuberculosis is one of the major health problems in developing countries like India. Even though lungs are the commonly involved organs in Tuberculosis, extrapulmonary presentations are on the rise nowadays. Among the various types of presentations of extrapulmonary tuberculosis, lymphadenitis is the most common presentation. A spectrum of investigations is available for diagnosis, and molecular methods like CBNAAT and PCR analysis are highly reliable. But their disadvantage is their cost and requirement of trained personnel. FNA is the first line of investigation but is lacking in sensitivity and culture method is time consuming. So, Modified Ziehl Neelsen method with low cost and less time may be considered as an alternative. We wanted to evaluate the sensitivity of the Modified Bleach Ziehl Neelsen method and compare the Modified and Conventional Ziehl Neelsen Method in association with the CBNAAT in the diagnosis of TB lymphadenitis.METHODSDiagnostic validation study was conducted with 30 clinically suspected cases of tuberculosis. FNA was done and aspirated material was spread on 2 slides. Slides were stained with H & E stain and convention Ziehl Neelsen stain. Part of the aspirate material was centrifuged with 5 % sodium hypochlorite. Sediment was smeared on a slide and stained with Ziehl Neelsen stain. Remaining material was subjected to CBNAAT assay.RESULTSCorrelation shows that 9, 6, and 11 out of 30 cases were positive for tuberculosis in Conventional, Modified and CBNAAT methods respectively. Sensitivity was 81.81 %; specificity was 94.74%, positive predictive value was 90% and negative predictive value was 90% for Conventional Ziehl Neelsen Method and 54.55%, 94.73%, 85.71% and 78.26%, respectively for modified bleach method.CONCLUSIONSConventional method is found to be more sensitive than modified method. CBNAAT negative results do not rule out TB. So, they should be correlated with cytology and microbiological studies.

Identification of pulmonary paragonimiasis using Ziehl-Neelsen stain

Pulmonary paragonimiasis and tuberculosis are endemic in Asia, South America, and Africa. However, differential diagnosis among the diseases is difficult because they present with similar clinical symptoms and diagnostic features. Here, we report a case of pulmonary paragonimiasis that was identified using Ziehl-Neelsen stain after initially being assessed for pulmonary tuberculosis. Following anti-Paragonimus chemotherapy, the patient's symptoms, laboratory test results, and lung lesions improved. Thus, the identification of Paragonimus westermani using Ziehl-Neelsen stain can be considered in the diagnosis.

Detection of Cryptosporidium spp. in Diarrheic Immunocompetent Patients in Beni-Suef, Egypt: Insight into Epidemiology and Diagnosis

Cryptosporidium species is an important cause of gastrointestinal infections globally. This study aimed to shed light on its role in diarrheic immunocompetent patients in Beni-Suef, Egypt and to compare three diagnostic methods. Two hundred diarrheic patients, 37±16.8 year old, were enrolled. Stool samples were examined by light microscopy, using modified Ziehl-Neelsen stain (MZN) for Cryptosporidium spp. oocysts. Coproantigens were detected by sandwich ELISA. DNA molecular diagnosis was done by nested PCR. PCR yielded the highest detection rates (21.0%), compared to ELISA (12.5%) and MZN staining method (9.5%). The higher infection rates were in 20–40 year-old group, followed by 40–60 year-old. Association between epidemiologic factors was statistically not significant; positivity and gender, clinical manifestations, residence, source or water, or contact with animals. Cryptosporidiosis is an important enteric parasitic infection in Beni-Suef and PCR remains the gold standard for diagnosis.

Evaluation on a modified Ziehl-Neelsen stainin the diagnosis of tuberculous meningitis / 中国神经精神疾病杂志

Objective Toevaluatea modified Ziehl-Neelsen(Z-N) stain in the diagnosis of tuberculous meningitis. Methods Cerebrospinal fluid specimens from 35 patients were stained by using the modified Ziehl-Neelsen staining. Re-sults The positive rate was 94.29% in 35 patients with tuberculous meningitisand the intracellular acid-fast bacilli was detected in 53.40%of all specimens. One case was stained positive in 15 patients with non-tuberculous meningitis. Con-clusion The modified Ziehl-Neelsen stain not only significantly improves the detection rates of tuberculous meningitisbut alsois able to identify intracellular M.tuberculosisin cerebrospinal fluidspecimen.Thus, the modified Z-N stain can be a convenient tool for diagnosing tuberculous meningitis.

Primary Nasopharyngeal Tuberculosis.

Tuberculous infection of the upper respiratory tract is an uncommon clinical condition and in that nasopharyngeal involvement is struck with rarity per se. This condition is often prevalent in people of low socioeconomic strata living in endemic areas, especially in developing countries. It has a silent and indolent course and most commonly mimicks nasopharyngeal carcinoma in its clinical presentation. In absence of concurrent pulmonary involvement, it is often misdiagnosed or diagnosed only after the biopsy has been taken. Nevertheless, high index of suspicion is required on part of the clinician to diagnose this comparatively rare entity.

Características clínicas y sociodemográficas de niños menores de 13 años con diagnóstico confirmado de tuberculosis pulmonar o sin él, en el Hospital Universitario San Vicente de Paúl, Medellín, Colombia, 2007-2008 / Clinical and sociodemographic characteristics of children, younger than13 years, with or without a confirmed diagnosis of pulmonary tuberculosis, at Hospital Universitario San Vicente de Paúl, Medellín, Colombia, 2007-2008

Introducción: la tuberculosis (TB) es una de las enfermedades infectocontagiosas más importantes en el mundo debido a que se asocia con altas tasas de morbilidad y mortalidad. En niños puede afectar cualquier órgano o sistema, a cualquier edad, pero con mayor frecuencia es pulmonar. Tiene graves consecuencias si no se la diagnostica y trata de forma oportuna y adecuada. Los síntomas y signos son variados e inespecíficos lo que, sumado a la dificultad en el aislamiento del Mycobacterium tuberculosis a partir de muestras de niños disminuye la probabilidad de hacer el diagnóstico. Objetivo: puntualizar las características clínicas y sociodemográficas de un grupo de niños con sospecha o diagnóstico final de tuberculosis pulmonar. Metodología: la población en estudio correspondió a 56 niños menores de 13 años atendidos en los servicios pediátricos de urgencias y hospitalización del Hospital Universitario San Vicente de Paúl, en Medellín, a quienes se les sospechó o confirmó TB pulmonar, según los criterios de la OMS, entre julio de 2007 y diciembre de 2008. Se aplicó un formulario para la recolección de los datos, que se obtuvieron directamente de los pacientes o sus acudientes, y se completaron con las historias clínicas en el archivo del hospital. Resultados: en 38 de los 56 niños (67,9%) se confirmó el diagnóstico de tuberculosis pulmonar. El 87,5% pertenecían a los estratos socioeconómicos más bajos (1 y 2); 55% provenían del área urbana de Medellín, 70% eran mestizos y 28,6%, indígenas. La tos y la fiebre fueron las manifestaciones más comunes en el grupo con diagnóstico definitivo de TB; el criterio epidemiológico fue positivo en 53,6% de los casos, el radiológico en 51,8% y el tuberculínico, en 41,1%. Conclusión: la TB pulmonar sigue presente en la población infantil y se debe tener un alto índice de sospecha clínica para detectarla, pues las manifestaciones son variadas e inespecíficas...

Introduction: Worldwide, tuberculosis is one of the most important infectious and contagious diseases. It is associated with high morbidity and mortality rates. In children, tuberculosis is most frequently pulmonary but it may affect every organ and system. Its consequences, if inadequately treated, may be severe. Symptoms and signs are diverse and nonspecific, and the bacteriological confirmation is difficult in children. For these reasons, making the diagnosis in the pediatric population may be a really difficult challenge.Objective: To determine the sociodemographic and clinical characteristics of a group of children with suspicion or confirmed diagnosis of pulmonary tuberculosis.Methodology: Fifty six children were studied at Hospital Universitario San Vicente de Paúl, in Medellín, Colombia, between July 2007 and December 2008. Pulmonarytuberculosis was confirmed according to the WHO criteria. Information was obtained from the patients themselves, their parents, and the hospital files. Results: In 38 of the 56 children (67.9%) pulmonary tuberculosis was confirmed. Their socioeconomic situation was poor in 87.5% of the cases; 55% came from the urban area of the city; 70% were mestizo, and 26.8%, Indians. Cough and fever were the predominant clinical manifestations. The positivity rate of diagnostic criteria was as follows: 53.6% for the epidemiological, 51.6% for the radiological, and 41.1% for the tuberculin test. Conclusion: Pulmonary tuberculosis continues to be of great importance in the pediatric population...

No siempre una baciloscopía positiva indica tuberculosis: Otra razón para solicitar cultivos rutinariamente / A positive sputum smear test is not always indicative of pulmonary TB: Another reason to order routine cultures

La detección de bacilos alcohol-ácido resistentes en un frotis teñido constituye la primera evidencia bacteriológica de la presencia de micobacterias en caso de sospecha de tuberculosis. Sin embargo, este hecho no debe ser considerado como sinónimo de tuberculosis ya que puede indicar, además de la presencia de Mycobacterium tuberculosis, la de micobacterias no tuberculosas e incluso la de otros gérmenes con propiedades tintoriales de ácido-resistencia, como la Nocardia spp. Se presentan dos pacientes que fueron referidos a la Clínica de Tuberculosis del Hospital General de Tijuana por fracaso terapéutico, con persistencia de baciloscopías positivas en expectoración, y cuya evaluación final demostró que no padecían tuberculosis.

The Ziehl-Neelsen (IN) stain is rapid and economic technique for the identification of acid-fast organisms, primarily Mycobacterium tuberculosis. However, the presence of acid-fast bacilli can not be considered as proof of tuberculosis; there is a wide variety of acid-fast microorganisms including non-tuberculous mycobacteria and even Nocardia spp and this could be a cause of misidentification. To illustrate this point, we present a patient with pulmonary nocardiosis and another with non-tuberculous mycobacteriosis that were initially misdiagnosed and treated for tuberculosis.

A comparison of sputum examination for acid fast bacilli By modified cold stain and ziehl-neelsen stain for screening of pulmonary tuberculosis.

A comparative study of the conventional Ziehl-Neelsen (ZN) stain and a new modified cold (MC) stain was carried out to evaluate the efficiency of this staining method in sputum examination for acid fast bacilli (AFB). The MC technique was simplified by avoiding the need for heat and combining the stage of counterstaining to overcome the problem aerosolized phenol and the more laborious heating method. Of the 392 sputum samples examined, 84 were positive and 297 were negative on both staining techniques, with an agreement of 97.2%. In comparison with culture as the gold standard for the diagnosis of tuberculosis, the ZN stain exhibited a sensitivity, specificity, positive and negative predictive values and efficiency of 68.9, 97.4, 92.1, 87.8 and 88.8%, respectively. The same values for the MC stain were 70.6, 97.8, 93.3, 88.4 and 89.5%, respectively with no statistically significant differences (P > 0.05) between the 2 methods. The MC stain was also as reliable as the ZN stain in retaining the color of the stained slide after prolonged storage; an agreement with the first reading was 90% after 4 weeks storage and 80% after 16 weeks storage. The staining reagents had a long shelf life; with agreement between both staining methods of 100% at every time of re-stocking aliquots. To apply this new MC stain for future use at the peripheral level of the health care system, we made a survey by using questionnaires sent to 200 hospitals. Most of the respondants also accepted that the MC stain was easier to perform, more comfortable and much less expensive than the ZN stain. Together, these factors make the MC stain suitable for use as a practical and rapid sputum staining test for screening for patients with pulmonary tuberculosis and for assessment of their treatment.

A Prospective Study of Ziehl-Neelsen Stain and Mycobacterial Culture of Pleural Fluid and Closed Pleural Biopsy Specimen in Tuberculous Pleural Effusion / 감염

BACKGROUND: Tuberculous pleural effusion is the most common extrapulmonary site of all disease due to Mycobacterium tuberculosis. The diagnosis of tuberculous pleural effusion is most often established by histologic examination of pleural biopsy specimens. This study documents the utility of smear and culture of pleural fluid and pleural biopsy specimens for tubercle bacilli. METHODS: Between March 1998 and August 1999, we performed thoracentesis with or without pleural bio-psies on 148 patients with pleural effusion according to protocol with Abrams needle. Before the pleural biopsy, a diagnostic thoracentesis was performed. Aliquots of pleural fluid (30 mL) were submitted for biochemical, cytologic, and bacteriologic studies, Ziehl-Neelsen staining and culture in Lowenstein-Jensen medium. At least five samples of parietal pleural tissue were obtained, one for mycobacterial study and another for histologic study. RESULTS: Thirty-seven of the 148 patients were proved to have tuberculosis (24 men and 13 women) with a median age of 32 years (range, 21~91). Pleural biopsy was performed on 35 of the 37 patients with tuberculous pleural effusion. Granuloma was present in 33 of the 35 patients investigated with acid-fast bacilli in 9 patients. The smear for acid-fast bacilli of pleural fluid was positive in 1 patient and the culture for M. tuberculosis was positive in 5 of 37 patients. Pleural biopsy culture was positive in 3 of 35 patients. The 2 patients who could not carry out the pleural biopsy were positive in pleural fluid and pleural tissue mycobacterial culture, respectively. CONCLUSION: In our test, Ziehl-Neelsen staining and culture for M. tuberculosis of pleural fluid and pleural specimen gave a higher yield (5.4%) than the histologic methods alone in establishing the diagnosis of tuberculous pleural effusion.

Comparison of Stain Methods with PCR and Culture for the Detection of Mycobacterium Tuberculosis in the Sputum / 대한임상병리학회지

BACKGROUND: Currently, many laboratories have selected several different methods for the detection of M. tuberculosis in the sputum. To select efficient method for clinical laboratories among the various methods, we compared the results of several methods. METHODS: Total 72 sputums were examined by the six combinations of stain methods. The samples were constructed as follows on the result of direct smear ZN stain; negatives (26), traces (3), 1+(9), 2+(12), 3+(12) and 4+(10). The true positives were determined after close evaluation of the clinical, radiological and other laboratory findings. RESULTS: The sensitivities and specificities of each methods were as follows; direct smear ZN stain were 83.6% and 100%, direct smear Auramine stain were 90.9% and 100%, centrifugation ZN stain were 94.6% and 100%, centrifugation Auramine stain were 98.2% and 94.1%, cytocentrifugation ZN stain were 96.4% and 100%, cytocentrifugation Auramine stain were 100% and 64.7%, nested PCR were 80% and 94.1% and culture were 67.3% and 100% respectively. CONCLUSIONS: Concentration method by centrifugation is suitable for routine laboratory if enough centrifugal force were engaged. Auramine stain is more suitable staining method than ZN stain in direct smear but not in concentrated smear because it has the potency of false positivity. The PCR assay is thought to be not only a fast, sensitive method but also a specific method for the direct detection of M. tuberculosis in the sputum. The culture method using Ogawa media is specific but not sensitive.

Comparative Assessment of Immunohistochemical and Zieh1-Neelsen Stains for Demonstration of Mycobacterium Tuberculosis

To obtain a useful method for the identification of mycobacteria in tissue section, we evaluated 118 cases of tuberculosis: 48 pulm onary, 14 lymph nodal and 56 synovial tuberculosis. Seventy nine of these cases underwent the culture study. Sections stained with anti-Mycobacterium bovis were compared with the results of the Zieh1-Neelsen stain and culture. The immunohistochemical stain for Mycobacterium bovis in al examined cases was not any more sensitive than the Zieh1-Neelsen stain(p>0.05). Neverthless, the immunohistochemical stain was a useful method for the localization of mycobacteria because of the striking contrast between its background and the wider dimension of a positive area. Immunoreactive areas demonstrated a few intact mycobacteria showing a positive reaction in the Zieh1-Neelsen stain. In conclusion, double staining method using the immunohischemical stain for Mycobacterium bovis and the Zieh1-Neelsen stain is an efficient technique in oder to confirm the diagnosis of tuberculosis.