Flagellar expression in clinical isolates of non-typeable Haemophilus influenzae

PURPOSE

Haemophilus influenzae is a commensal organism found in the upper respiratory tract of humans. When H. influenzae becomes a pathogen, these bacteria can move out of their commensal niche and cause multiple respiratory tract diseases such as otitis media, sinusitis, conjunctivitis and bronchitis in children, and chronic obstructive pulmonary disease in adults. However, H. influenzae is currently considered a non-flagellate bacterium.

METHODOLOGY AND RESULTS

In this study, 90 clinical isolates of H. influenzae strains (typeable and non-typeable) showed different degrees of the swarm-motility phenotype in vitro.Keys findings. One of these strains, NTHi BUAP96, showed the highest motility rate and its flagella were revealed using transmission electron microscopy and Ryu staining. Moreover, the flagellar genes fliC and flgH exhibited high homology with those of Actinobacillus pleuropneumoniae, Escherichia coli and Shigella flexneri. Furthermore, Western blot analysis, using anti-flagellin heterologous antibodies from E. coli, demonstrated cross-reaction with a protein present in NTHi BUAP96.

CONCLUSION

This study provides, for the first time, information on flagellar expression in H. influenzae, representing an important finding related to its evolution and pathogenic potential.

Performance of the clinical index of stable febrile neutropenia (CISNE) in different types of infections and tumors

PURPOSE

The clinical index of stable febrile neutropenia (CISNE) can contribute to patient safety without increasing the complexity of decision-making. However, febrile neutropenia (FN) is a diverse syndrome. The aim of this analysis is to assess the performance of CISNE according to the type of tumor and infection and to characterize these patients.

METHODS

We prospectively recruited 1383 FN episodes in situations of apparent clinical stability. Bonferroni-adjusted z tests of proportions were used to assess the association between the infections suspected at the time of onset and the type of tumor with the risk of serious complications and mortality. The performance of CISNE was appraised in each category using the Breslow-Day test for homogeneity of odds ratios and Forest Plots.

RESULTS

171 patients had a serious complication (12.3 %, 95 % confidence interval 10.7-14.2 %). The most common initial assumptive diagnoses were: fever without focus (34.5 %), upper respiratory infection (14.9 %), enteritis (12.7 %), stomatitis (11.8 %), and acute bronchitis (10.7 %). Lung and breast were the most common tumors, accounting for approximately 56 % of the series. The distribution of complications, mortality, and bacteremia varies for each of these categories. However, Breslow-Day tests indicate homogeneity of the odds ratio of the dichotomized CISNE score to predict complications in all infection and tumor subtypes.

CONCLUSION

Despite FN's clinical and microbiological heterogeneity, the CISNE score was seen to be consistent and robust in spite of these variations. Hence, it appears to be a safe tool in seemingly stable FN.