Molecular serovar characterization of Leptospira isolates from animals and water in Colombia / Caracterización molecular de serovariedades de Leptospira spp. aisladas de muestras de animales y agua en Colombia

Introduction: Leptospirosis is a bacterial disease transmitted directly or indirectly from animals to humans that may result in severe hemorrhagic, hepatic/renal and pulmonary disease. There are 20 known Leptospira species and hundreds of serovars, some of which belong to different species. It is essential to identify pathogenic Leptospira serovars and their potential reservoirs to prepare adequate control strategies. Objective: To characterize the Leptospira serovars isolated from rodents, dogs, pigs and water samples in Colombia. Materials and methods: Leptospira organisms were isolated and cultured, and pathogenic strains were identified using a polymerase chain-reaction (PCR). Leptospira DNA and Salmonella Braenderup H9812 (molecular weight standard) DNA were cleaved using NotI and subjected to pulsed-field gel electrophoresis (PFGE). The PFGE patterns were analyzed based on bacterial strain-typing criteria and Dice coefficients (DCs) between these isolates and over 200 Leptospira organisms isolated from other parts of the world. Results: All of the isolates were pathogenic strains, and five were genetically characterized. The P275 (84% DC) and P282 (95% DC) pig isolates were related to the Leptospira interrogans Pomona serovar; the I15 (DC: 100%) rat isolate was identical to the Leptospira interrogans Icterohameorrhagiae or Copenhageni serovars, while the C67 (64% DC) dog and A42 (60% DC) water isolates were not related (< 73.7% DC) to any of the 200 reference serovars; the closest serovars were the Leptospira noguchii Nicaragua and Orleans serovars, respectively. Conclusion: This was the first molecular characterization of Colombian Leptospira spp isolates; these isolates will be used to develop a Colombian diagnostic panel.

Introducción. La leptospirosis es una infección bacteriana transmitida directa o indirectamente de animales a humanos, la cual puede resultar en una enfermedad hemorrágica grave, hepática o renal y pulmonar. Hay 20 especies de Leptospira conocidas y cientos de serovariedades, algunas de las cuales pertenecen a diferentes especies. Es esencial identificar las serovariedades patógenas y sus reservorios potenciales para enfocar estrategias de control. Objetivo. Caracterizar las serovariedades de Leptospira aisladas de muestras de roedores, perros, cerdos y agua en Colombia. Materiales y métodos. Las cepas de leptospiras aisladas fueron identificadas como patógenas usando la reacción en cadena de la polimerasa (PRC). Sus ADN y el ADN de Salmonella Braenderup H9812 (marcador de peso molecular) fueron cortados con NotI y corridos en electroforesis de campo pulsado. Los patrones de la ECP se analizaron con base en los criterios de tipificación para cepas bacterianas y el coeficiente de Dice, cuando se compararon con 200 cepas aisladas en otras partes del mundo. Los perfiles de ADN con un coeficiente de Dice entre 73,7 % y 100 % se consideraron pertenecientes a la misma especie. Resultados. Todos los aislamientos fueron cepas patógenas y cinco se caracterizaron genéticamente. El aislamiento P275 (coeficiente de Dice: 84 %) y el P282 (coeficiente de Dice: 95 %) de cerdos, se relacionaron con Leptospira interrogans de serovariedad Pomona; el aislamiento de rata (I15) fue indistinguible de Leptospira interrogans de serovariedades Icterohaemorrhagiae o Copenhageni (coeficiente de Dice: 100 %), mientras que los aislamientos de perro (C67) y agua (A42) no se relacionaron (coeficiente de Dice <73,7 %) con ninguna de las 200 cepas de referencia; las más cercanas fueron Leptospira noguchii de serovariedades Nicaragua (coeficiente de Dice: 63 %) y Orleans (coeficiente de Dice: 60 %). Conclusiones. Esta fue la primera caracterización molecular de serotipos de aislamientos colombianos, los cuales serían los primeros miembros de un panel diagnóstico colombiano.

Epidemiology of Helicobacter pylori infection in Barbados

The epidemiology of Helicobacter pylori infection in Barbadian patients and controls was studied. H. pylori was isolated from biopsies from 50/100 (50 percent) adult patients undergoing endoscopy for investigation of upper gastrointestinal tract symptoms. Urease was detected in biopsies from 54 patients and gastritis was detected by histology in 71 patients. Serology was performed using a commercial ELISA method. Using an IgG concentration of 10 U/ml as a threshold, antibodies were detected in 78 percent of 100 patients undergoing endoscopy, 72 percent of 230 blood donors and 22 percent of 50 children. The mean antibody concentration was significantly higher in patients (92 U/ml) than in blood donors (49 U/ml) or in children (9.5 U/ml). Culture-positive patients (120 U/ml) had higher IgG concentration than culture-negative patients (64 U/ml). Using isolation of H. pylori or a positive biopsy urease test as a measure of true prevalence of infection, the sensitivity of serology was 96 percent, the specificity 42 percent positive predictive value 67 percent and negative predictive value 90 percent. Seroprevalence increased with age, to a peak of more than 90 percent in blood donors aged 50 - 59 years and in patients aged over 60 years. The epidemiology of H. pylori in Barbados is similar to that in developed countries, where few children was infected, but resembles other developing countries in the high seroprevalence observed in middle-aged adults.

Genital tract infections in sexually active women in Barbados

Ninety-eight women attending three different clinics were prospectively studied for the presence of genital tract infections, including Chlamydia trachomatis. Of these 98 women, 35 were presenting to a polyclinic with symptoms of genital tract infection, 55 were attending an antenatal clinic for their first visit, and 8 referred to a colposcopy clinic because of an abnormal Papanicolaou smear were included. Gonorrhoea was detected in one patient, syphilis in two, and Trichomonas vaginalis in six. Candida albicans and Chlamydia trachomatis were each detected in 18 patients, while the most common condition was bacterial vaginosis, detected in 35 patients. The prevalence of these infections was lowest in patients referred for colposcopy and highest in the women attending the antenatal clinic, Chlamydia trachomatis was the most common sexually-transmitted pathogen detected in this population. These data emphasise the need for an aggressive approach to the diagnosis and treatment of chlamydial infection in females

Antibiotic sensitivity of neisseria gonorrhoeae isolates in Barbados; longitudinal surveillance 1990-1994

The antimicrobial susceptibility of 775 isolates of Neisseria gonorrhoeae, recovered in Barbados over a five-year period, was studied by disc diffusion. Sensitivity to penicillin declined from 56 percent in 1990 to 38 percent in 1994. The prevalence of ß-lactamase production rose from 30 percent to 50 percent during this period and sensitivity to tetracycline declined from 96 percent to 46 percent, while co-trimoxazole and spectinomycin sensitivities varied. Ceftriaxone, norfloxacin and erythromycin were the only compounds tested to which sensitivity remained uniform. The results confirm the current recommendations by several agencies that ceftriaxone or an oral fluoroquinolone should be considered the drug of choice for the empirical treatment of gonorrhoea

Aetiology of vaginal infections in pregnant and non-pregnant women in Barbados

The aetiology of vaginal discharge was studied in 175 Barbadian women. Pregnant women accounted for 52 percent (91) of the population studied. Candida albicans was detected in 45 percent of the women, bacterial vaginosis in 28 percent and Trichomonas vaginalis in 8.6 percent. Bacterial vaginosis was more common in non-pregnant women (33 percent vs 23 per cent) whereas C. albicans was more common in pregnant women. Mixed infections were found in 10 women and an aetiological agent was detected in 75 percent of the women studied. These data emphasize the need for laboratory investigation of vaginal discharge since each of these infections can be treated effectively with specific agents

Seroepidemiology of chlamydial infection among a sexually-active population in Barbados

During a two-year period, sera from 1179 patients with urogenital tract symptoms and from 256 controls were tested for IgG and IgA antibodies to Chlamydia trachomatis, using a commercially prepared indirect immunoperoxidase assay. Of the patient sera, 1051 (89//) were from female patients and 128 (11//) were from males. Specimens were received from patients attending private practitioners (424), government polyclinics (348), the Queen Elizabeth Hospital (206), the Barbados Family Planning Association (117) and various other source (84). Nine hundred and fifty-nine of specimens (81//) from all patients had IgG titres of 64 or greater, and 441 (37//) had IgA titres of 16 or greater. A lower proportion of male patients (43//) than female patients (61//) had IgG titres of 128 or greater. Among 76 control females attending the antenatal clinic, IgG were detected in 76//and IgA in 16//, while among 75 adult blood donors, IgG was detected in 70//and IgA in 39//. A group comprising 97 asymptomatic children aged 9 months to 13 years, and 8 adolescents aged 14 - 18 years was also studied. IgG antibodies (titre ñ 64) were detected in 13.4//of children and in 50//of the adolescents. IgA antibodies were detected in only 1//of children and adolscents. Antibodies were not detected in children under the age of 5 years. The detection of antibodies by indirect immunoperoxidase assay in such a high proportion of the population suggests that this method is of little value for diagnosis of infection with Chlamydia trachomatis

Helicobacter pylori in patients undergoing upper endoscopy in Jamaica

One hundred and two consecutive patients undergoing upper gastrointestinal endoscopy were tested for H. pylori by a rapid urease test, using antral biopsy specimens. There were 60 men (mean age 54 yrs) and 42 women (mean age 49 yrs). Fifty-six patients (55//) were positive for H. pylori. Of male patients, 36 (60//) and of female patients, 20 (48//) tested positive. Sixty-eight per cent of patients with antral gastritis, 65//with duodenal ulcer and 60//with gastric ulcer had H. pylori. Thirty-nine patients (70//) positive for H. pylori were from major urban areas, and 17 (30//) were from rural areas of Jamaica. In patients without H. pylori, 61//and 39//were from urban and rural areas respectively. Forty-four patients (79//) with H. pylori and 40 (87//) without H. pylori had piped water in their homes. Ninety-three per cent of all patients had electricity and 88//had refrigeration. There was no difference between patients positive or negative for H. pylori with regard to the use of alcohol, marijuana or tobacco. There was also no difference between both groups in exposure to domestic animals in the home environment. H. pylori is associated with antral gastritis and peptic ulcer disease in Jamaican patients. There are no specific environmental or social factors that seem to predispose to infection.

Resistance to third-generation cephalosporins in Barbados

Resistance to third-generation, or extended-spectrum, cephalosporins caused by induction of class I B-lactamases has been reported rarely from developing countries. Seven isolates of cephalosporin-resistant Gram-negative rods were recovered recently from urine, burns and ulcers in the Queen Elizabeth Hospital, Barbados. The isolates were identified as Acinetobacter calcoacetius (2), Citrobacter freundii (1), Enterobacter cloacae (1), Morganella ;morganii (1), Providencia stuartii (1) and Proteus sp. (1). Induction of B-lactamase by cefoxitin was demonstrated, and minimal inhibitory concentratrions (MIC) were determined by agar dilution. B-lactamases were demonstrated by isoelectric focusing; the presence of chromosal B-lactamases were confirmed in at least three of the resistant isolates. The only antibiotics which were uniformly active against these resistant strains were imipenem and ciprofloxacin. These data confirm the existence of resistance to the third-generation cephalosporins in Barbados, and emphasise the necessity for continuous surveillance of resistance patterns in the Caribbean region.

Analysis of pathogens isolated from urinary tract infections in Barbados

The isolation of pathogens from urine specimens was surveyed during a six-month period when 1611 urine specimens were examined in the Public Health Laboratory, and 8769 were examined in the Microbiology Laboratory of the Queen Elizabeth Hospital. Significant growth (defined as >10 organisms/ml urine) was detected in 393 (24,4 per cent ) of the urine cultured in the Public Health Laboratory and in 1218 (13.9 per cent ) of urines cultured in the Queen Elizabeth Hospital. The overall isolation rate 15.5 per cent ; Gram-negative bacilli were more commonly isolated from hospital patients, whereas Gram-positive cocci were relatively more common in community patients. The most common pathogens detected were coliforms (1233 isolates), streptococci (197) and coagulase-negative straphylococci (182); 50 per cent of all isolates were sensitive to amoxycillin, 68 per cent to cephradine, 61 per cent to co-trimoxazole, 62 per cent : to nalidixic acid and 79 per cent to nitrofurantoin. Anti-bacterial activity was detected in 130 (8 per cent ) of the urine specimens received in the Public Health Laboratory.

Necrotizing haemorrhagic colitis caused by resistant shigella flexneri. Report of a case

A case of fatal infection with shigella flexneri is reported. The 19-year-old male patient who presented with fulminating haemorrhagic colitis died nine days after the onset of symptoms. The infecting strain of shigella flexneri was resistant to multiple antimicrobial agents, including amoxycillin, co-trimoxazole and chloramphenicol.