Microbial aetiology of acute rhinosinusitis during pregnancy.

BACKGROUND: Pregnancy as an immunosuppressive condition and with the associated tendency for mucosal oedema can predis- pose women to acute rhinosinusitis. Our hypothesis was that pregnancy enhances opportunistic sinus infections. METHODOLOGY: We retrospectively collected data on pregnant women with acute rhinosinusitis treated at the Department of Otorhinolaryngology, Helsinki University Hospital, Finland in 2010-2015. Maxillary puncture was performed on all patients, and patients with purulent sinus secretions and bacterial culture were included in the study. Clinical data on patients and microbial findings of bacterial cultures were recorded and compared with those of non-pregnant controls. RESULTS: Ninety-five pregnant patients and 91 controls were included. The bacterial cultures of pregnant patients revealed bac- terial growth more often than control patients’ specimens (78.9% vs. 54.9%). The most common bacterial findings (pregnant vs. control patients) were Streptococcus pneumoniae 43.2% vs. 20.9%, Haemophilus influenzae 22.1% vs. 16.5%, and Moraxella catar- rhalis 10.5% vs. 2.2%. S. pneumoniae was the most frequent finding in all trimesters, and the proportion of S. pneumoniae sinusitis was highest during the last trimester of pregnancy. CONCLUSIONS: The pathogens of acute rhinosinusitis in pregnant patients are the same as in non-pregnant patients, however, the proportions differ; during pregnancy S. pneumoniae infection is more frequent.

Validation of an antimicrobial susceptibility testing protocol for Brachyspira hyodysenteriae and Brachyspira pilosicoli in an international ring trial.

Brachyspira hyodysenteriae and Brachyspira pilosicoli cause economically important enteric disease in pigs. Treatment of these infections often includes antimicrobial administration, which can be most effective when therapeutic options are informed by antimicrobial susceptibility testing data. Here we describe a method for broth dilution antimicrobial susceptibility testing of these bacteria, both of which are difficult to culture in vitro. The protocol was evaluated for its fitness for use in an inter-laboratory ring trial involving eight laboratories from seven countries, and employing eleven test strains (5 Brachyspira hyodysenteriae including the type strain B78T and 6 Brachyspira pilosicoli) and six antibiotics. Overall intra- and inter-laboratory reproducibility of this method was very good (>90 % MICs at mode +/- 1 log2). Whole genome sequencing revealed good correspondence between reduced susceptibility and the presence of previously defined antimicrobial resistance determinants. Interestingly, lnu(C) was identified in B. pilosicoli isolates with elevated MICs of lincomycin, whilst tva(B) was associated with elevated MICs of pleuromutilins in this species. We designated two new control strains with MICs lying within currently tested ranges, including for the pleuromutilins, in contrast to the control strain B. hyodysenteriae B78T. These were deposited at the DSMZ-German Collection of Microorganisms and Cell Cultures GmbH. The validation of a standard protocol and identification of new control strains facilitates comparisons between studies, establishment of robust interpretative criteria, and ultimately contributes to rational antimicrobial use when treating infected livestock.

Quality-control ranges for antimicrobial susceptibility testing by broth dilution of the Brachyspira hyodysenteriae type strain (ATCC 27164T).

There are no approved standards for antimicrobial susceptibility testing of the fastidious spirochete Brachyspira hyodysenteriae. An interlaboratory study was performed to establish MIC quality control ranges for six antimicrobial agents for the type strain of B. hyodysenteriae using broth dilution. The results showed that B. hyodysenteriae B78T ATCC 27164T is a suitable quality control strain. This is a first step toward standardization of methods regarding this anaerobe.

Tiamulin resistance in porcine Brachyspira pilosicoli isolates.

There are few studies on antimicrobial susceptibility of Brachyspira pilosicoli, therefore this study was performed to investigate the situation among isolates from pigs. The tiamulin and tylosin susceptibility was determined by broth dilution for 93 and 86 porcine B. pilosicoli isolates, respectively. The isolates came from clinical samples taken in Swedish pig herds during the years 2002 and 2003. The tylosin minimal inhibitory concentration (MIC) was >16 microg/ml for 50% (n=43) of the isolates tested. A tiamulin MIC >2 microg/ml was obtained for 14% (n=13) of the isolates and these were also tested against doxycycline, salinomycin, valnemulin, lincomycin and aivlosin. For these isolates the susceptibility to salinomycin and doxycycline was high but the MICs for aivlosin varied. The relationship between the 13 tiamulin resistant isolates was analyzed by pulsed-field gel electrophoresis (PFGE). Among the 13 isolates 10 different PFGE patterns were identified.

Further characterization of porcine Brachyspira hyodysenteriae isolates with decreased susceptibility to tiamulin.

Brachyspira hyodysenteriae is the causative agent of swine dysentery, a severe diarrhoeal disease in pigs. Few drugs are available to treat the disease, owing to both antimicrobial resistance and withdrawal of drugs authorized for use in pigs. Tiamulin is the drug of choice in many countries, but isolates with decreased susceptibility have recently been reported. The mechanism of tiamulin resistance in B. hyodysenteriae is not known and this facet is essential to understand the dissemination of the trait. To study the resistance epidemiology of B. hyodysenteriae, further characterization of a set of isolates from Germany (n = 16) and the UK (n = 6) with decreased susceptibility to tiamulin was performed. The relatedness between the isolates was studied by comparing PFGE patterns, and the in vitro susceptibility to five other antimicrobials (aivlosin, doxycycline, salinomycin, chloramphenicol and avilamycin) was also determined. For comparison of the antimicrobial-susceptibility pattern, Swedish (n = 20) and British (n = 4) tiamulin-susceptible isolates were tested. The German isolates represented several different PFGE patterns, indicating that tiamulin usage has been sufficient to select clones with decreased tiamulin susceptibility at different farms in Germany. The PFGE pattern for the six British isolates with decreased tiamulin susceptibility was identical to that of the German isolates, and they had a similar antimicrobial-susceptibility pattern, except for resistance to aivlosin, which was only found in a few German isolates. No other co-resistance with tiamulin was found.

Outcomes of manual extracapsular versus phacoemulsification cataract extraction by beginner resident surgeons.

PURPOSE: To evaluate the safety and efficacy of phacoemulsification cataract extraction and manual extracapsular cataract extraction (ECCE) performed by beginning resident surgeons. SETTING: Dallas Veterans Affairs Medical Center, Dallas, Texas, USA. DESIGN: Retrospective cohort study. METHODS: A review was performed of each resident's series of initial cataract surgery procedures as a late first-year or second-year resident. Data were collected for cases performed over almost a 6-year period during which initially the first primary surgeon cases were ECCE and later, the first primary surgeon cases were phacoemulsification. For each case, the following data were gathered: technique of cataract extraction, laterality, resident, vitreous loss or dropped nucleus, placement of posterior chamber intraocular lens (IOL), and need for reoperation within 90 days of surgery. RESULTS: Complications occurred in 6 (2.5%) of 244 cases in which phacoemulsification was performed by a beginner resident primary surgeon and in 7 (4.1%) of 172 cases in which ECCE was used (P=.40). Posterior chamber IOLs were placed in all but 2 phacoemulsification cases and 4 ECCE cases (P=.24). Moreover, 3 cases in the phacoemulsification group and 1 case in the ECCE group required a reoperation within 90 days (P=.65). CONCLUSION: Phacoemulsification cataract extraction can be taught safely and effectively to residents with no cataract surgery experience as a primary surgeon.

Characterization of plasmid-mediated AmpC-producing E. coli from Swedish broilers and association with human clinical isolates.

A selection of plasmid-mediated AmpC-producing Escherichia coli isolates carrying blaCMY-2 from Swedish broilers were characterized to establish their relatedness to and a possible overlap with human clinical E. coli isolates. The results showed diversity among the E. coli isolated from broilers, indicating that the spread in the population was not due to one strain. However, only one type of plasmid belonging to replicon type incK was identified. Furthermore, there were no indications of spread of blaCMY-2 E. coli isolates from broilers to human clinical settings, although Swedish broilers may be a source of blaCMY-2 and/or the plasmid carrying blaCMY-2 .

Antimicrobial susceptibility testing of porcine Brachyspira (Serpulina) species isolates.

No standardized method for susceptibility testing of Brachyspira spp. is currently available. A broth dilution procedure was evaluated and used to test the activities of six antimicrobial agents for 108 isolates of Swedish porcine Brachyspira spp. representing biochemical groups I, II, and III. Group I corresponds to Brachyspira hyodysenteriae, group II corresponds to B. intermedia, and group III corresponds to B. murdochii and B. innocens. A panel was designed with the antimicrobial agents dried in tissue culture trays with wells that allowed a liquid volume of 0.5 ml in each and agitation of the broth when incubated on a shaker. The MICs were determined by using brain heart infusion broth with 10% fetal calf serum. For 10 isolates, the results obtained in broth were compared to the MICs obtained on two different types of agar. Different inoculum densities and incubation times were also compared. The concentrations at which 90% of the B. hyodysenteriae isolates (n = 72) were inhibited in the broth dilution test by tiamulin (0.25 micro g/ml), tylosin (>256 micro g/ml), erythromycin (>256 micro g/ml), clindamycin (>4 micro g/ml), virginiamycin (4 micro g/ml), and carbadox (0.06 micro g/ml) were determined. The MICs tended to be lower in broth than on agar. Differences in inoculum densities and incubation times had little influence on the MICs. The evaluated broth dilution test was simple to perform, the end points were easily read, and the results were reproducible and reliable. No isolates with decreased susceptibility to tiamulin were found among the Swedish isolates tested.