A Gardnerella vaginalis e as infecções do trato urinário / The Gardnerella vaginalis and the urinary tract infections

As infecções do trato urinário (ITUs) estão entre as mais frequentes nos seres humanos. São causadas por grande variedade de uropatógenos habituais, porém podem ser provocadas por alguns micro-organismos fastidiosos, como a Gardnerella vaginalis, que é uma bactéria anaeróbia facultativa, observada sob a forma de cocobacilos Gram-variáveis. Ela habita a mucosa vaginal e eventualmente pode ocasionar ITUs. O isolamento pode ser realizado em amostras de urina utilizando o ágar CNA (colistina e ácido nalidíxico), com incubação de 48 a 72 horas em atmosfera rica em CO2. O exame de Gram de urina não centrifugada pode auxiliar o microbiologista na identificação das amostras nas quais uma bactéria fastidiosa seja o agente causal, já que a visualização de inúmeras células epiteliais, a ausência de leucócitos e a presença de mais de um tipo morfológico sugerem contaminação da amostra. Como estudos comprovam a incidência de G. vaginalis entre os agentes causadores de ITUs, o isolamento em uroculturas não deve ser desprezado. A interpretação clínica do crescimento da G. vaginalis é de difícil avaliação, sendo imprescindível a troca de informações entre o laboratório de microbiologia clínica e a equipe médica, investigando a presença de sinais e sintomas que possam estar associados à ITU.

Urinary tract infections are among the most recurrent in human beings. They are caused by a wide variety of usual uropathogens, although they may be caused by some fastidious micro-organisms, such as Gardnerella vaginalis. It is a facultative anaerobe, found in the form of Gram-variable coccobacilli. It inhabits the vaginal mucosa and occasionally may cause urinary tract infections. The isolation may be performed on urine samples using CNA agar, incubated for 48-72 hours in atmosphere rich in CO2. The Gram examination of non-centrifuged urine may aid the microbiologist in identifying samples in which a fastidious bacterium is the causative agent, since the visualization of numerous epithelial cells, the absence of leukocytes and the presence of more than one morphological type suggest sample contamination. As studies show the Gardnerella vaginalis incidence among the causative agents of urinary tract infections, the isolation in urine cultures can not be overlooked. The clinical interpretation of the Gardnerella vaginalis growth is difficult to assess, thus being essential the information exchange between the clinical microbiology laboratory and medical staff in order to investigate the presence of signs and symptoms that may be associated with urinary tract infections.

Pathogen Distribution and Drug Resistance of Respiratory Tract Infection in Children / 中华医院感染学杂志

OBJECTIVE To investigate pathogenic bacteria isolated from children with respiratory tract infection and bacterial resistance to commonly used antimicrcrobial agents. METHODS Routine methods were used to isolate and identify fastidious bacteria and Streptococcus from children throat swabs. The drug susceptibility tests were performed by Kirby-Bauer method. RESULTS One hundred and twenty four pathogenic bacteria were isolated from 300 samples. The isolation rate was 41.3% and the fastidious bacteria were 78 strains(62.9%). The resistant rate of Haemophilus influenzae to clarithromycimn, trimethoprim-sulfamethoxazoe(SXT) and ampicllin was 70.0%, 60.0%and 66.7%, respectively. The resistant rate of Streptococcus pneumoniae to tetracycline, clindamycin, SXT and azithromycin was 96.2% 92.3% 92.3% and 92.3%, respectively; the resistant rate of Streptococcus pyogenes to tetracycline, clidamycin and azithromyoin was 100.00%, 94.45% and 83.33%, respectively. CONCLUSIONS Fastidion bacteria and S. pyogenes are the main Pathogenic bacteria in children with respiratory tract infection. The antimicrobial agents should be chosen according to antimicrobial sasceptibility test results.