Eva Grahn Håkansson

Effect of recolonisation with "interfering" alpha streptococci on recurrences of acute and secretory otitis media in children: randomised placebo controlled trial.

Abstract Objective: To study the effect of recolonisation with α streptococci with the ability to inhibit the growth of otopathogens (“interfering” activity) on the recurrence of acute otitis media in susceptible children and the effect on the frequency of secretory otitis media. Design: Double blind, randomised, placebo controlled study. Setting: Ear, nose, and throat clinic with three doctors. Participants: 130 children prone to otitis media aged between 6 months and 6 years, 108 of whom were eligible and followed for 3 months. Main outcome measures: Recurrence of otitis media during follow up and a normal tympanic membrane at the last valid visit. Interventions: Children with no recurrences during the last month received phenoxymethylpenicillin (n=22), and those with a recurrence within 1 month received amoxicillin clavulanic acid (n=86), both twice daily for 10 days. These were followed by a streptococcal or placebo solution sprayed into the nose for a further 10 days. At day 60 the same spray was started for another 10 days. Results: At 3 months 22 children (42%) given the streptococcal spray were healthy and had a normal tympanic membrane compared with 12 (22%) of those given placebo. This difference was shown separately for recurrences of both acute otitis media and secretory otitis media. Conclusions: Selected bacteria with the ability to inhibit the growth of common otopathogens can be used to protect against recurrent acute otitis media and secretory otitis media in children.

Spray bacteriotherapy decreases middle ear fluid in children with secretory otitis media

Objective: Secretory otitis media (SOM) is characterised by persistent fluid in the middle ear cavity, but the cause is unknown. We investigated the clinical, bacteriological and immunological effects of treatment with probiotic bacteria on SOM. Design: In this double-blind pilot/preliminary study, 60 children with long-standing SOM (median 6 months) who were scheduled for insertion of tympanostomy tubes were randomised to nasal spray treatment with Streptococcus sanguinis, Lactobacillus rhamnosus or placebo for 10 days before surgery. Clinical evaluation was carried out after 10 days of treatment. Middle ear fluid (MEF) was collected during surgery for quantification of cytokines and detection of bacteria by culture and polymerase chain reaction (PCR). Nasopharyngeal swabs were obtained before treatment and at surgery. Results: Complete or significant clinical recovery occurred in 7/19 patients treated with S sanguinis compared to 1/17 patients in the placebo group (p<0.05). In the L rhamnosus treatment group, 3/18 patients were cured or much better (p = 0.60 compared with placebo). Spray treatment did not alter the composition of the nasopharyngeal flora or the cytokine pattern observed in the nasopharynx or MEF, except for a higher level of IL-8 found in the nasopharynx of L rhamnosus treated children. Conclusions: This study shows that spray treatment with S sanguinis may be effective against SOM. The mechanism for the effect remains to be investigated.

Intestinal flora in very low-birth weight infants

Aim:  To study the early faecal microbiota in very low‐birth weight infants (VLBW, <1500 g), possible associations between faecal microbiota and faecal calprotectin (f‐calprotectin) and to describe the faecal microbiota in cases with necrotizing enterocolitis (NEC) before diagnosis.

A nasal spray with alpha-haemolytic streptococci as long term prophylaxis against recurrent otitis media

Previous studies have shown that children with recurrent acute otitis media (rAOM) have significantly lower quantities of alpha-haemolytic streptococci (AHS) in the nasopharynx than healthy children. Furthermore children with otitis media have AHS with lower inhibitory activity in vitro on Streptococcus pneumoniae and non-typable Haemophilus influenzae compared with healthy children. A randomised, placebo controlled and double blind clinical study among children with rAOM was designed to determine whether or not a nasal spray, containing AHS with very good inhibitory activity on the three most common OM pathogens, could be an alternative to tympanostomy tube insertion. Forty three children under 4 years of age were included in the study. The children sprayed once daily for 4 months and were monitored for 6 months. Sixteen children in the active group and 20 children in the placebo group were evaluated. The result showed no significant differences regarding the number of episodes of AOM, with seven recurrences in the active group and eight in the placebo group. No significant changes of the nasopharyngeal flora could be detected during the study period regarding the OM pathogens. Nasal spray according to the performed schedule is not yet an alternative to tympanostomy tubes in children with rAOM. The possibility of increasing the efficacy of this ecological treatment, by using pre-treatment antibiotics, more adhesive bacteria and alternative treatment schedules is discussed.

Bacterial Interference Between Pathogens in Otitis Media and Alpha-Haemolytic Streptococci Analysed in an In Vitro Model

Bacterial interference studied by means of agar methods has shown a decreased number of inhibitory alpha-haemolytic Streptococci among otitis-prone children. Additional information was gained regarding the interplay between alphahaemolytic Streptococci (AHS) and otitis media (OM) pathogens by comparing the bacterial interference in broth with the interference activity studied using agar overlay methods. We found that non-typeable Haemophilus influenzae (NTHI) and Moraxella catarrhalis are readily inhibited by AHS in broth. Streptococcus pneumoniae was more bacteriostatically inhibited. If two OM pathogens were inoculated simultaneously, an isolate of AHS with poor inhibitory activity was not able to inhibit the growth, in contrast to an isolate of AHS with good inhibitory activity. The initial amount of AHS inoculated with M. catarrhalis seemed to play a decisive role with respect to the inhibitory activity. M. catarrhalis developed reduced susceptibility against AHS both in vivo and in vitro . In vivo studies showed that children with secretory otitis media had fewer isolates of AHS in their nasopharynx with the ability to inhibit all the test pathogens than healthy children ( p < 0.001). Although the factor(s) responsible for the inhibitory activity have thus far not been defined, we could exclude low pH and nutrition depletion as the inhibitory mechanism of AHS with good inhibitory activity.

Selection and characterization of a Lactobacillus plantarum strain promising as a urogenital probiotic

Vaginally isolated Lactobacillus strains (n=511) were evaluated for probiotic properties in the female urogenital region. A strain of Lactobacillus plantarum designated LB931 showed several desirable properties and was found to grow and reduce the pH in MRS broth rapidly, to produce substances totally inhibiting growth of common urogenital pathogens, and to remain viable during long-term storage. It was not affected by antimycotics or spermicidals and it adhered to the urogenital surface. Strain LB931 possesses properties required by probiotic bacteria aimed to improve or restore the female urogenital microflora.

Is hydrogen peroxide responsible for the inhibitory activity of alpha-haemolytic streptococci sampled from the nasopharynx?

Objective—The inhibitory effect of alpha-haemolytic Streptococci (AHS) in vitro on the three commonest otitis media pathogens, Streptococcus pneumoniae, Haemophilus influenzae and Moraxella catarrhalis, was previously investigated. The aim of this study was to determine the mechanism of this inhibitory activity. Material and Methods—When fractions of AHS filtrate were assayed to determine their inhibitory activity after size-exclusion chromatography, the inhibitory activity was found in the fractions with a low molecular weight. The inhibitory effect was completely reversed when catalase was added to the cell-free filtrate of AHS. A quantitative method also revealed high production (approximately 3 mmol/l) of hydrogen peroxide in the AHS filtrate with the best inhibitory activity. Electron microscopy of bacteria exposed to AHS filtrate with an inhibitory effect showed changes similar to bacteria exposed to hydrogen peroxide. Results—When fractions of AHS filtrate were assayed to determine their inhibitory activity after size-exclusion chromatography, the inhibitory activity was found in the fractions with a low molecular weight. The inhibitory effect was completely reversed when catalase was added to the cell-free filtrate of AHS. A quantitative method also revealed high production (approximately 3 mmol/l) of hydrogen peroxide in the AHS filtrate with the best inhibitory activity. Electron microscopy of bacteria exposed to AHS filtrate with an inhibitory effect showed changes similar to bacteria exposed to hydrogen peroxide. Conclusions—We conclude that the inhibitory effect of AHS is most likely due to the production of hydrogen peroxide. The significance of hydrogen peroxide production of AHS is discussed in relation to the non-specific and specific mucosal defence systems.

Draft Genome Sequence of the Oral Commensal Streptococcus oralis 89a with Interference Activity against Respiratory Pathogens

ABSTRACT We report the draft genome sequence of the oral commensal Streptococcus oralis 89a isolated from the throat of a healthy child during a streptococcal tonsillitis outbreak in Umeå, Sweden. S. oralis 89a was known to have interference activity against respiratory pathogens in which the colicin V was the potential bacteriocin-encoding gene.