Pielonefritis por Escherichia coli en el Hospital Naval de Guayaquil-Ecuador / Pielonefritis by Escherichia coli in the Naval Hospital of Guayaquil-Ecuador

La Pielonefritis por Escherichia coli con frecuencia es de diagnóstico confuso haciéndose necesario combinar pruebas de urología con las de imagenologías, pudiendo generar complicaciones renales hasta poder convertiste en un caso hepático grave por las lesiones que se les infrinja a los riñones, es por ello que esta investigación se planteo como objetivo caracterizar los casos de Pielonefritis por E. coli en el Hospital Naval de Guayaquil. Estudio descriptivo de corte transversal, con una muestra de 33 pacientes. Empleando como técnica de recolección de datos sus historias clínicas, pruebas de sedimento urinario, urocultivo en medio aerobico y pruebas de imagenología. Teniendo como resultado que el sexo femenino (60,61%; n=20/33), con un 60,61% (n=20/33) evidencian diabettus milletus, con grado de inducción primaria 24,24% (n=8/33), presentando dolor lumbar (100% n=33/33), con dolor al orinar y nauseas (90,91%; n=30/33), en los exámenes de urología las colonias/ml valores>105 fue de 57,58% (n=19/33) con E. coli (100%; n=33/33) y las pruebas de imagenología arrojaron que un 60,61% (n=20) evidencia gas en el colector solo sistema, confirmando el diagnóstico pielonefritis. En conclusión, por lo solapado que tiende a ser el diagnostico del Pielonefritis por E. coli deben combinarse las pruebas de urología y las de imágenes(AU)

Pyelonephritis by Escherichia coli is often of confused diagnosis making it necessary to combine urology tests with imaging, may cause renal complications until you can become a serious liver case due to injuries to the kidneys, That is why this research was aimed at characterizing the cases of Pyelonephritis by E. coli in the Naval Hospital of Guayaquil. Descriptive cross-sectional study, with a sample of 33 patients. Using as a data collection technique their clinical histories, urine sediment tests, uroculture in an aerobic environment and imaging tests. As a result, the female sex (60,61%; n=20/33), with 60.61% (n=20/33) showed diabettus milletus, with degree of primary induction 24.24% (n=8/33), presenting lumbar pain (100% n=33/33), with pain when urinating and nausea (90.91%; n=30/33), in urology examinations the colonies/ml values>105 was 57.58% (n=19/33) with E. coli (100%; n=33/33) and imaging tests showed that 60,61% (n=20) gas in the collector only system, confirming the diagnosis pyelonephritis. In conclusion, because of the overlapping that tends to be the diagnosis of Pyelonephritis by E. coli, urology and imaging tests should be combined(AU)

Bilateral pyelonephritis due to Escherichia coli infection in a captive jaguar (Panthera onca) / Pielonefrite bilateral por Escherichia coli em uma onça-pintada (Panthera onca)

Extraintestinal pathogenic Escherichia coli (ExPEC) is a highly diverse pathotype of E. coli which colonizes the intestine, and it is considered an important etiological agent associated with bacteremia and other systemic infections, among them urinary tract infection. Retrospective studies evaluating morbidity and mortality of nondomestic felids have demonstrated that urinary tract diseases are among the main causes of death for geriatric animals. Also, mesenchymal neoplasms of the uterus are common in wild felids, and they possess variable morphologic characteristics related to invasiveness and malignancy. This report describes a case of bilateral pyelonephritis due to extraintestinal uropathogenic E. coli infection in a captive jaguar (Panthera onca). The diagnosis was confirmed through pathological, bacterial and immunohistochemical findings. According to molecular analysis, this E. coli strain was classified in the phylogroup F, possessing the following virulence-associated genes: usp, cnf-1, hlyA, papC and sfa. Additionally, this E. coli was highly resistant to beta-lactams and first-generation cephalosporin. This jaguar also presented a uterine leiomyoma with distinct distribution, and severe degenerative articular disease, both of them described as frequently seen lesions in geriatric animals from the Panthera genus.(AU)

Escherichia coli extraintestinal patogênica (ExPEC) é um patotipo altamente diverso de E. coli que coloniza o intestino e é considerada um agente etiológico importante, associado com bacteremia e outras infecções sistêmicas, dentre elas infecções do trato urinário. Estudos retrospectivos avaliando morbidade e mortalidade de felídeos não domésticos demostram que doenças do trato urinário estão entre as principais causas de morte de animais geriátricos. Ainda, neoplasias mesenquimais uterinas são comuns em felídeos de cativeiro e possuem características morfológicas variáveis relacionadas a invasividade e malignidade. Neste relato é descrito um caso de pielonefrite bilateral por E. coli extraintestinal uropatogênica em uma onça-pintada de cativeiro (Panthera onca). O diagnóstico foi confirmado através dos achados patológicos, bacteriológicos e imuno-histoquímicos. A partir da análise molecular, esta cepa de E. coli foi classificada no filogrupo F, possuindo os seguintes genes associados a virulência: usp, cnf-1, hlyA, papC and sfa. Adicionalmente, a bactéria isolada foi altamente resistente a ß-lactâmicos e cefalosporinas de primeira geração. Foi observado ainda um leiomioma uterino com distribuição distinta e doença articular degenerativa severa, ambas descritas na literatura como comumente observadas em animais geriátricos do gênero Panthera.(AU)

Procalcitonin determined at emergency department as an early indicator of progression to septic shock in patient with sepsis associated with ureteral calculi

ABSTRACT Introduction: To investigate the role of initial procalcitonin (PCT) level as an early predictor of septic shock for the patient with sepsis induced by acute pyelonephritis (APN) secondary to ureteral calculi. Materials and Methods: The data from 49 consecutive patients who met criteria of sepsis due to APN following ureteral stone were collected and divided into two groups: with (n=15) or without (n=34) septic shock. The clinical variables including PCT level for this outcome were retrospectively compared by univariate analysis, followed by multivariable logistic regression model. Results: All subjects had hydronephrosis, and were hospitalized with the mean of 11.8 days (3–42 days). The mean size of the ureteral stones was 7.5mm (3–30mm), and 57% were located in upper ureter. At univariate analysis, patients with septic shock were significantly older, a higher proportion had hypertension, lower platelet count and serum albumin level, higher CRP and PCT level, and higher positive blood culture rate. Multivariate models indicated that lower platelet count and higher PCT level are independent risk factors (p=0.043 and 0.046, respectively). In ROC curve, the AUC was significantly wider in PCT (0.929), compared with the platelet count (0.822, p=0.004). At the cut-off of 0.52ng/mL, the sensitivity and specificity were 86.7% and 85.3%. Conclusion: Our study demonstrated elevated initial PCT levels as an early independent predictor to progress into septic shock in patients with sepsis associated with ureteral calculi.

Pregnancy outcomes in pregnant women with abnormal glucose challenge test

Some studies have shown that pregnant women with abnormal glucose challenge test [GCT] and normal oral glucose challenge test [OGTT] have the chance of adverse pregnancy outcomes including macrosomia, pre-eclampsia and increase of cesarean section rate. This study was performed to determine the pregnancy outcomes in women with abnormal glucose challenge test. This case -control study was done on 60 pregnant women with abnormal GCT [more than 130 mg/dl] and normal OGTT and 67 pregnant women with normal GCT [less than 130 mg/dl] in Kermanshah, Iran during September 2010-March 2011. Delivery with Vacum, polyhydroamnus, pre-eclampsia pyelonephritis and low birth weight significantly was higher in cases than controls [P<0.05]. But there was a non significant difference in stillbirth, neonatal abnormality, neonatal respiratory distress and shoulder dystocia between case and control groups. Polyhydramnious, preeclampsia and pyelonephrities and low birth weight are more frequent in pregnant women with abnormal GCT and normal OGTT in compare to pregnant women with normal GCT

Carcinoma renal con translocación XP11.2: informe de un caso con énfasis en los diagnósticos diferenciales / Renal carcinoma with translocation XP11.2: a case report with emphases in differential diagnostic

En adultos el carcinoma de células renales con translocación Xp11.2 es una neoplasia poco frecuente representando menos del 1% de todas las neoplasias renales. Analizar las características morfológicas de un carcinoma con translocación Xp11.2 y establecer los posibles diagnósticos diferenciales de este tumor renal. Paciente femenina de 45 años de edad, quien en mayo de 2008 acudió a emergencia por dolor en flanco izquierdo. Un ecosonograma abdominal evidenció litiasis renal izquierda y lesión sólida en polo inferior, la cual fue confirmada por tomografía abdominal. Se realizó nefrectomía laparoscópica izquierda, sin complicaciones. El espécimen quirúrgico fue enviado al departamento de patología fijado en formol tamponado al 10% y procesado para histología e inmunohistoquímica. Macroscópicamente, se evidenció en el polo inferior renal una lesión tumoral de 45 mm x 40 mm x 35 mm, amarillenta-anaranjada, con áreas de necrosis. Las secciones histopatológicas mostraron una lesión epitelial con patrón predominante papilar. Las células tumorales mostraban bordes citoplasmáticos discretos, con citoplasma eosinófilo granular y zonas vacuoladas. Se evidenció variabilidad de la forma y contorno nuclear. La inmunohistoquímica mostró reactividad nuclear para el TFE3. La correcta clasificación de estos carcinomas es importante por los factores pronósticos y predictivos, ya que estas neoplasias pueden ser sensibles a agentes quimioterapéuticos que afectan los micro túbulos.

In adult life, the kidney carcinomas associated with Xp11.2 translocations are an infrequent neoplasia representing less than the 1% of all kidneys neoplasias. To analyze the morphologic characteristics of a carcinoma with Xp11.2 translocation and to establish the probable differential diagnostics of this kidney tumour. A 45 years-old female patient, who at May 2008 was admitted to emergency by left flank pain. An abdominal ultrasound showed a left renal lithiasis and a solid lesion at the inferior pole, which was confirmed by the abdominal tomography. A left laparoscopic nephrectomy was performed without complications. The surgical specimen was send to the pathology department in 10% buffered formalin and processed to histology and immunohistochemestry. Macroscopically was observed at the inferior kidney pole a yellow orange tumor lesion with necrosis and 45 mm x 40 mm x 35 mm in size. The histopathologic sections showed an epithelial lesion with papillary pattern. The tumour cells showed discrete cytoplasmatic borders, with granular eosinophil to vacuolated appearance. Nuclei showed variability in form and size. The immunohistochemical study showed a nuclear positivity to TFE3. The correct classification of these carcinomas is important due to the prognostic and the predictive factors, since these neoplasias could be sensible to the chemotherapeutics agents that affect the micro tubules.

Evaluation of interleukin-10 production in pseudomonas aeruginosa induced acute pyelonephritis

Pseudomonas aeruginosa is an opportunistic pathogen of immunocompromised hosts. This pathogen has a tendency to form biofilms on the surface of indwelling catheters leading to acute and chronic urinary tract infections that result in significant morbidity and mortality. In the present study, kinetics of interleukin-10 [IL-10] production in mouse renal tissue was studied employing experimental mouse model of acute pyelonephritis induced with planktonic and biofilm cells of P. aeruginosa. IL-10 production was found to be significantly lower in biofilm cell instilled mice compared to planktonic cell infected animals, which corroborated with higher bacterial load and tissue damage. The data suggests that downregulation of IL-10 production may be novel strategy employed by biofilm cells to cause tissue damage and hence bacterial persistence. The results of the present study may open up avenues of research that will ultimately provide the foundation for the development of preventative measures and therapeutic strategies to successfully treat P. aeruginosa biofilm infections based on the administration of anti-inflammatory agents

Freqüência dos sinais de pielonefrite aguda em pacientes submetidos a tomografia computadorizada / Acute pyelonephritis: frequency of findings in patients submitted to computed tomography

OBJETIVO: Estimar a freqüência das alterações tomográficas renais e extra-renais em pacientes com pielonefrite aguda e avaliar o grau de concordância interobservador. MATERIAIS E MÉTODOS: Realizamos trabalho retrospectivo a partir da análise dos exames de tomografia computadorizada de 47 pacientes com diagnóstico clínico e laboratorial de pielonefrite aguda. Dois examinadores independentes avaliaram as principais alterações renais, perirrenais e extra-renais. Foi medida a freqüência dos achados tomográficos e a concordância interobservador por meio do teste kappa (kapa). RESULTADOS: A freqüência dos achados tomográficos para os diversos parâmetros estudados foi: nefrograma heterogêneo, 100 por cento; nefromegalia, 65 por cento; heterogeneidade da gordura, 62,5 por cento; nefrolitíase, 16,6 por cento; abscessos, 21 por cento; derrame pleural, 36 por cento; espessamento da vesícula biliar, 32,5 por cento; edema periportal, 32,5 por cento. O teste kapa para a concordância interobservador demonstrou reprodutibilidade variando entre moderada (kapa = 0,511 para nefromegalia) e quase perfeita (kapa = 0,87 para nefrograma heterogêneo) para todos os parâmetros estudados, exceto para a heterogeneidade da gordura perirrenal (kapa = 0,268). CONCLUSÃO: A freqüência dos diversos achados tomográficos de pielonefrite aguda é elevada, sendo o nefrograma heterogêneo o sinal mais comum. Alterações perinefréticas e extra-renais são observadas em até dois terços dos casos. A tomografia computadorizada apresenta boa concordância interobservador.

OBJECTIVE: The present study was aimed at establishing the frequency of renal/perirenal and extrarenal computed tomography findings in patients with acute pyelonephritis, and evaluating the interobserver agreement. MATERIALS AND METHODS: Retrospective study based on the analysis of computed tomography images of 47 patients with clinical and laboratory findings of acute pyelonephritis. Two independent observers evaluated the main renal/perirenal and extrarenal alterations. The frequency of tomographic findings and interobserver agreement were analyzed by the kappa (k) test. RESULTS: The frequency of tomographic findings for the several parameters was the following: striated nephrogram, 100 percent; renal enlargement, 65 percent; perirenal fat heterogeneity, 62.5 percent; renal calculi, 16.6 percent; abscesses, 21 percent; pleural effusion, 36 percent; thickened gallbladder wall, 32.5 percent; periportal edema, 32.5 percent. The k test for interobserver agreement demonstrated reproducibility ranging between moderate (k = 0.511 for renal enlargement) to almost perfect (k = 0.87 for striated nephrogram) for all of the parameters analyzed, except for perirenal fat heterogeneity (k = 0.268). CONCLUSION: The frequency of findings of acute pyelonephritis on computed tomography is high. Overall, striated nephrogram was the most frequent finding. Peri- and extra-renal alterations were found in about 2/3 of the cases. Computed tomography demonstrated a good interobserver agreement.

Pielonefrite enfisematosa em enxerto renal: relato de caso / Emphysematous pyelonephritis in renal: allograft-case report

Pielonefrite enfisematosa é uma rara complicação após o transplante renal. Este é um relato de caso de uma paciente diabética de 42 anos de idade, do sexo feminino, que se apresentou após uma semana de tratamento de infecção do trato urinário causada por Escherichia coli, referindo uma massa palpável sobre o enxerto. A tomografia computadorizada de abdome mostrou coleção perirrenal contendo ar. Tratada com antibióticos e drenagem percutânea. Após 20 dias de drenagem, recebeu alta hospitalar com função renal estável.

Emphysematous pyelonephritis is a rare post renal transplant complication. This is a case report of a 42 year-old diabetic female, who presented a urinary tract infection caused by Escherichia coli and a palpable mass above the graft approximately 1 week after treatmtent, A computer tomography scan of the abdomen showed peri-renal collection containing air. The patient was treated with antibiotics and a percutaneous nephrostomy was performed. After 20 days of drainage, renal function was considered stable and she was discharged from the hospital.

Spontaneous nephrocutaneous fistula in tuberculous pyelonephritis

A rare case of spontaneous nephrocutaneous fistula with renal tuberculosis is presented here. A 70 years old male with neglected stones in right kidney was investigated for discharging sinus right lumbar region of three months duration. Excretory urography revealed non-functioning right kidney and an impacted stone right upper ureter and a small stone in renal pelvis. The patient was successfully treated by nephroureterectomy and excision of the fistulous track followed by anti-tuberculous treatment. Histopathology of the specimen revealed renal tuberculosis. Though the incidence of various forms of tuberculosis is very high in this part of the world, presence of nephrocutaneous fistula is still uncommon

Experimental supratrigonal cystectomy: evaluation of long-term complications

OBJECTIVE: The present study aims at assessing the occurrence of pyelonephritis and long-term complications in rats submitted to surgical reduction of bladder capacity. MATERIALS AND METHODS: Sprague-Dawley rats were submitted to supratrigonal cystectomy (29 animals) or sham operation (15 animals) and sacrificed 2, 4 and 6 months after the surgical procedure. The arterial blood pressure and serum creatinine levels were assessed before the surgery and at the time of the sacrifice. After the sacrifice a careful inspection of the urinary apparatus was performed to the characterization of the hydronephrosis and for the detection of the presence of calculi. With sterile technique, the urine was aspirated from the bladder and the kidneys removed and sent to a microbiologic study. RESULTS: Pyelonephritis was frequent in animals submitted to supratrigonal cystectomy. The most frequent and isolated microorganisms were Staphylococcus sp. and E. coli. The presence of urinary calculi was correlated significantly to the presence of urinary tract infection (p < 0.003). Arterial hypertension was frequent amongst animals submitted to supratrigonal cystectomy. Serum creatinine was high in 72.4 percent of the animals in the group submitted to supratrigonal cystectomy. The presence of calculi and pyelonephritis were frequent in rats presenting renal insufficiency and in hypertensive rats. CONCLUSIONS: The long-term course of urinary infection in rats submitted to supratrigonal cystectomy was characterized by a high incidence of renal insufficiency and arterial hypertension that seem to be related to dysfunction and bladder obstruction induced by an extensive surgical procedure and the presence of urolithiasis and pyelonephritis.

Laparoscopic treatment of refluxing segmental megaureter

We discuss the case of a 13-year old boy with urinary infection who was preoperatively diagnosed with left vesicoureteral reflux associated with paraurethral saccule. Laparoscopic Lich-Gregoir anti-reflux surgery was then proposed. Intraoperatively, we observed segmental megaureter that was successfully treated by the proposed technique without ureteral modeling, contrary to the rule that respects the 3-5 times ratio between the submucous path and the ureteral diameter.

Pyelonephritic potential of Pseudomonas aeruginosa in ascending mouse model.

The suitability of female BALB/c and Swiss Webster (LACA) strains of mice for an ascending model of pyelonephritis for human uroisolate of Pseudomonas aeruginosa, was assessed. A fresh isolate of Ps. aeruginosa elaborating virulence factors like elastase, protease, phospholipase C, pyochelin and haemolysin was selected and introduced transuretherally in mice without any manipulation of the urinary tract. This isolate was able to colonize and persist in the renal tissue till day 12 post infection. Histopathologically, severe renal lesions i.e., abscesses formation was observed. The LACA strain was found to be more susceptible to infection with the selected Ps. aeruginosa isolate.

Estudio prospectivo, randomizado, comparativo de la eficacia, seguridad y costos de cefuroxima vs cefradina en la pielonefritis aguda del embarazo / Efficacy, safety and cost of cefuroxime compared with cephradine in the treatment of acute pyelonephritis during pregnancy

Background: Second generation cephalosporins (CFPs) are more active in the treatment of acute pyelonephritis during pregnancy but their cost is considerably higher than their predecessors. Cefuroxime, a second generation CFP with oral and parenteral presentations, might offer significant advantages and become a first choice antimicrobial in this setting. Aim: To compare the efficacy, safety and cost of cefuroxime and cephradine in the treatment of acute pyelonephritis in pregnancy. Patients and methods: Hospitalized women with 12 to 34 weeks of pregnancy, with clinical and bacteriological diagnosis of acute pyelonephritis, were randomly assigned to receive cefuroxime (Curocef (r), GlaxoWellcome) 750 mg t.i.d, i.v or cephradine 1 g q.i.d., i.v. If the isolated organism was resistant to the assigned drug the patient was excluded. Once patients were afebrile, they were switched to an oral form of the same antimicrobial. They were discharged according to the clinical status and treated for a total of 14 days. Laboratory tests, including urine culture were requested during controls and at the end of follow-up at 28 days. Results: One hundred and one patients were randomized: 49 to receive cephradine and 52 to receive cefuroxime. Patients in the cefuroxime group had fewer febrile days (mean 1.7 vs 2.2, p<0.05), faster clinical recovery (mean 2.7 vs 3.1 days, p<0.05), a higher rate of bacteriological cure at 28 days (78.8 percent and 59.2 percent, p<0.05) and lower rate of failure (21.2 percent vs 40.8 percent p<0.05). The rate of resistance of isolated uropathogens was l4 percent to cephradine and 1 percent to cefuroxime. Conclusions: Cefuroxime can be considered as a first choice option in the treatment of acute pyelonephritis during pregnancy due to its tolerance, microbiological activity and efficacy

Riñón en herradura con doble sistema colector y compresión de la unión ureteropiélica inferior por vena renal accesoria. Caso clínico / Horseshoe kidney with dual collector system and compression of inferior ureteropyelic junction by an accesory renal vein. report of a case

Las alteraciones de la fusión renal se presentan frecuentemente asociadas a otras malformaciones renales, Se presenta en este artículo el caso de una paciente de 26 años de edad, asintomática durante la infancia, que inició su padecimiento con un cuadro de pielonefritis aguda con infección ulterior recurrente de vías urinarias; durante la protocolización del estudio se encontró un riñón en herradura con doble sistema colector completo e hidonefrosis del superior. Se sometió a lumbotomía exploradora y se realizó polectomía, y se identificó compresión extrínseca de la unión ureteropiélica izquierda por una vena renal accesoria

Pielonefritis, mecanismos patogénicos

La presencia de bacterias a nivel de la mucosa de las vías urinarias determina una respuesta inflamatoria. El factor responsable de la invasión de células inflamatorias es la IL6 (interleuquina 6) y los componentes bacterianos inductores son las adhesinas y el LPS de la membrana bacteriana. La actividad inflamatoria no es sólo responsable de los síntomas agudos sino de la eliminación bacteriana. En los estudios experimentales, los animales no reactivos al LPS fueron incapaces de eliminar las bacterias y en embarazadas se ha demostrado que una respuesta menor de IL6 puede relacionarse con la mayor incidencia de pielonefritis (1-4). La respuesta inflamatoria también ha sido relacionada con la producción de IL8 (interleuquina 8). Estudios en humanos han mostrado correlación entre concentración de IL8 urinaria y los recuentos leucocitarios (5).

Urinary tract infection in children

Urinary tract infection is predominant among school age girls. It may be complicated by renal scarring and other complications if not diagnosed early and properly treated. 108 children with proven U.T.I. based on colony count > 105 organisms/ml were included in the study. All cases were examined clinically and investigated by laboratory tests and radiologically [abdominal U.S., plain U.T. and I.V.U. and in some cases V.U.C. or DMSA scan]. E. coli was the most offending organism in the series [71%] followed by Klebsiella [15.3%], Pseudomonas [5%], Proteus [4.7%] and Staphylococci in 4% of patients. Renal scarring was detected in 17 cases [15.7%]. V.U.R. was encountered in 4 out of 14 children [28.6%] having renal scarring, which was not associated with renal and ureteral stones. No single radiological imaging technique is adequate for diagnosing various genitourinary abnormalities. I.V.U. is more accurate than U.S. in detecting renal scarring and some congenital anomalies like duplex collecting system. V.U.C. can detect different grades of reflux, while DMSA scan is the most accurate in diagnosing renal scarring

Pielonefritis crónica pseudotuberculosa: presentación de un caso y revisión de la literatura / Chronic pseudotuberculous pyelonephritis: report of a case and review of the literature

Este trabajo reporta el caso clínico de una mujer de 68 años de edad con un tipo de pielonefritis granulomatosis muy poco frecuente, asociada con nefrolitiasis. El informe anatomo-patologico de la nefrectomía demostró: Litiasis renal, pionefrosis y múltiples granulomas caseosos que contenían células multinucleadas similares a la TBC renal. No se encontraron bacilos tuberculoos ni otros micro-organismos en los urocultivos pre y post-operatorios, así como tampoco en el tejido renal. En la secreción purulenta del riñon se aisló E.coli

Pielonefritis enfisematosa: 3 casos / Enphysematous pyelonephritis: 3 cases

We report 3 patients who developed enphysemathous pyelonephritis. All were diabetic females over 50 years of age with unilateral necrotizing pyelonephritis. Intra and perirenal gas was demosntrated and all patients had infection by E. coli X ray and ultrasound studies allowed the diagnosis. Antibiotic therapy was unsuccessful and all patients had to be operated on

Xanthogranulomatous pyelonephritis

A case of xanthogranulomatous pyelonephritis is presented. It is an uncommon but well recognised entity of chronic bacterial pyelonephritis which may easily be mistaken for renal cell carcinoma, renal carbuncle or tuberculosis