The commensal pathogen Streptococcus mutans uses AgI/II adhesins to adhere to gp340 adsorbed on teeth. Here we analyzed isolates of S. mutans (n ‫؍‬ 70 isolates) from caries and caries-free human extremes (n ‫؍‬ 19 subjects) by multilocus sequence typing (MLST), AgI/II full-length gene sequencing, and adhesion to parotid saliva matched from the strain donors (nested from a case-control sample of defined gp340 and acidic proline-rich protein [PRP] profiles). The concatenated MLST as well as AgI/II gene sequences showed unique sequence types between, and identical types within, the subjects. The matched adhesion levels ranged widely (40% adhesion range), from low to moderate to high, between subjects but were similar within subjects (or sequence types). In contrast, the adhesion avidity of the strains was narrow, normally distributed for high, moderate, or low adhesion reference saliva or pure gp340 regardless of the sequence type. The adhesion of S. mutans Ingbritt and matched isolates and saliva samples correlated (r ‫؍‬ 0.929), suggesting that the host specify about four-fifths (r 2 ‫؍‬ 0.86) of the variation in matched adhesion. Half of the variation in S. mutans Ingbritt adhesion to saliva from the caries cases-controls (n ‫؍‬ 218) was explained by the primary gp340 receptor and PRP coreceptor composition. The isolates also varied, although less so, in adhesion to standardized saliva (18% adhesion range) and clustered into three major AgI/II groups (groups A, B 1 , and B 2 ) due to two variable V-region segments and diverse AgI/II sequence types due to a set of single-amino-acid substitutions. Isolates with AgI/II type A versus types B 1 and B 2 tended to differ in gp340 binding avidity and qualitative adhesion profiles for saliva gp340 phenotypes. In conclusion, the host saliva phenotype plays a more prominent role in S. mutans adhesion than anticipated previously.

Actinomyces naeslundii genospecies 1 and 2 bind to acidic proline-rich proteins (APRPs) and statherin via type 1 fimbriae and to ␤-linked galactosamine (GalNAc␤) structures via type 2 fimbriae. In addition, A. naeslundii displays two types of binding specificity for both APRPs-statherin and GalNAc␤, while Actinomyces odontolyticus binds to unknown structures. To study the molecular basis for these binding specificities, DNA fragments spanning the entire or central portions of fimP (type 1) and fimA (type 2) fimbrial subunit genes were amplified by PCR from strains of genospecies 1 and 2 and hybridized with DNA from two independent collections of oral Actinomyces isolates. Isolates of genospecies 1 and 2 and A. odontolyticus, but no other Actinomyces species, were positive for hybridization with fimP and fimA full-length probes irrespective of binding to APRPs and statherin, GalNAc␤, or unknown structures. Isolates of genospecies 1 and 2, with deviating patterns of GalNAc␤1-3Gal␣-O-ethyl-inhibitable coaggregation with Streptococcus oralis Ss34 and MPB1, were distinguished by a fimA central probe from genospecies 1 and 2, respectively. Furthermore, isolates of genospecies 1 and 2 displaying preferential binding to APRPs over statherin were positive with a fimP central probe, while a genospecies 2 strain with the opposite binding preference was not. The sequences of fimP and fimA central gene segments were highly conserved among isolates with the same, but diversified between those with a variant, binding specificity. In conclusion, A. naeslundii exhibits variant fimP and fimA genes corresponding to diverse APRP and GalNAc␤ specificities, respectively, while A. odontolyticus has a genetically related but distinct adhesin binding specificity.

Injured motor vehicle drivers who were hospitalized (Umeå: n = 130) and fatally injured drivers who were autopsied (Umeå, Northern Sweden: n = 111; Gothenburg, Western Sweden: n = 136) from May 1991 through December 1993 were tested for alcohol and for both licit and illicit drugs. Nineteen percent of the Umeå-hospitalized drivers (UHDs), 26% of the Umeå fatally injured drivers (UFDs), and 21% of the Gothenburg fatally injured drivers (GFDs) tested positive for drugs and/or alcohol. Ten percent of the UHDs, 8% of the UFDs, and 6% of the GFDs tested positive for drugs. Almost 5% of the UHDs, had illicit drugs, and 6% had licit drugs. Only 3% of the GFDs and none of the UFDs had illicit drugs. Benzodiazepines, followed by opiates, tetrahydrocannabinol, and amphetamine were the most common drugs detected. Twelve percent of the UHDs, 24% of the UFDs, and 17% of the GFDs tested positive for alcohol. Two percent of the UHDs, 6% of the UFDs, and 2% of the GFDs had a combination of drugs and alcohol.

Background: Actinomyces naeslundii genospecies 1 and 2 express type-2 fimbriae (FimA subunit polymers) with variant Galβ binding specificities and Actinomyces odontolyticus a sialic acid specificity to colonize different oral surfaces. However, the fimbrial nature of the sialic acid binding property and sequence information about FimA proteins from multiple strains are lacking.

Medically impairing injuries among medical personnel (n = 209) were analyzed based on data obtained from the Work-Related No-Fault Liability Insurance's (TFA) injury registration system. Almost half (98; 47%) were injured during patient care, of which 29 were injured as a result of physical trauma inflicted by the patient. When moving themselves between the homes of the patients and between different wards, 94 (45%) were injured (18 in vehicle crashes). The injuries most often resulting in medical impairment were sprains and/or strains (101; 48%) and fractures (67; 32%). The injuries primarily affected the upper extremities (48%). Fifteen percent had a medical impairment of 10% or more, and in about half of the cases, the impairment was 1% to 4%. Every injured person was on sick leave for 7 months, on average, during the 2-year follow-up period. In 12% of the cases, the injury led to a disability pension.