2019 John Charnley Award: Increased risk of prosthetic joint infection following primary total knee and hip arthroplasty with the use of alternative antibiotics to cefazolin: the value of allergy testing for antibiotic prophylaxis.

AIMS: The aims of this study were to characterize antibiotic choices for perioperative total knee arthroplasty (TKA) and total hip arthroplasty (THA) prophylaxis, assess antibiotic allergy testing efficacy, and determine rates of prosthetic joint infection (PJI) based on perioperative antibiotic regimen. PATIENTS AND METHODS: We evaluated all patients undergoing primary TKA or THA at a single academic institution between January 2004 and May 2017, yielding 29 695 arthroplasties (22 705 patients), with 3411 arthroplasties in 2576 patients (11.5%) having undergone preoperative allergy testing. A series of institutional databases were combined to identify allergy consultation outcomes, perioperative antibiotic regimen, and infection-free survivorship until final follow-up. RESULTS: Among 2576 allergy-tested patients, 2493 patients (97%) were cleared to use cephalosporins. For the entire cohort, 28 174 arthroplasties (94.9%) received cefazolin and 1521 (5.1%) received non-cefazolin antibiotics. Infection-free survivorship was significantly higher among arthroplasties receiving cefazolin compared with non-cefazolin antibiotics, with 0.06% higher survival free of infection at one month, 0.56% at two months, 0.61% at one year, and 1.19% at ten years (p < 0.001). Overall, the risk of PJI was 32% lower in patients treated with cefazolin after adjusting for the American Society of Anesthesiologists (ASA) classification, joint arthroplasty (TKA or THA), and body mass index (BMI; p < 0.001). The number needed to treat with cefazolin to prevent one PJI was 164 patients at one year and 84 patients at ten years. Therefore, potentially 6098 PJIs could be prevented by one year and 11 905 by ten years in a cohort of 1 000 000 primary TKA and THA patients. CONCLUSION: PJI rates are significantly higher when non-cefazolin antibiotics are used for perioperative TKA and THA prophylaxis, highlighting the positive impact of preoperative antibiotic allergy testing to increase cefazolin usage. Given the low rate of true penicillin allergy positivity, and the readily modifiable risk factor that antibiotic choice provides, we recommend perioperative testing and clearance for all patients presenting with penicillin and cephalosporin allergies. Cite this article: Bone Joint J 2019;101-B(6 Supple B):9-15.

Can a reverse shoulder arthroplasty be used to revise a failed primary reverse shoulder arthroplasty?: Revision reverse shoulder arthroplasty for failed reverse prosthesis.

AIMS: Patients with a failed reverse shoulder arthroplasty (RSA) have limited salvage options. The aim of this study was to determine the outcome of revision RSA when used as a salvage procedure for a failed primary RSA. PATIENTS AND METHODS: We reviewed all revision RSAs performed for a failed primary RSA between 2006 and 2012, excluding patients with a follow-up of less than two years. A total of 27 revision RSAs were included in the study. The mean age of the patients at the time of revision was 70 years (58 to 82). Of the 27 patients, 14 (52% were female). The mean follow-up was 4.4 years (2 to 10). RESULTS: Six patients (22%) developed complications requiring further revision surgery, at a mean of 1.7 years (0.1 to 5.3) postoperatively. The indication for further revision was dislocation in two, glenoid loosening in one, fracture of the humeral component in one, disassociation of the glenosphere in one, and infection in one. The five-year survival free of further revision was 85%. Five additional RSAs developed complications that did not need surgery, including dislocation in three and periprosthetic fracture in two. Overall, patients who did not require further revision had excellent pain relief, and significant improvements in elevation and external rotation of the shoulder (p < 0.01). The mean postoperative American Shoulder and Elbow Surgeons (ASES), and simple shoulder test (SST) scores were 66 and 7, respectively. Radiological results were available in 26 patients (96.3%) at a mean of 4.3 years (1.5 to 9.5). At the most recent follow-up, six patients (23%) had glenoid lucency, which were classified as grade III or higher in three (12%). Smokers had a significantly increased risk of glenoid lucency (p < 0.01). CONCLUSION: Revision RSA, when used to salvage a failed primary RSA, can be a successful procedure. At intermediate follow-up, survival rates are reasonable, but dislocation and glenoid lucency remain a concern, particularly in smokers. Cite this article: Bone Joint J 2018;100-B:1493-98.

First Report of Bacterial Leaf Spot of Basil Caused by Pseudomonas viridiflava in Hungary.

In April 2011, typical bacterial spot symptoms were observed on sweet basil plantlets (Ocimum basilicum L.) in a supermarket in Budapest, Hungary. Affected plants had dark brown-to-black lesions on the cotyledons. Spots on the leaves were first water soaked and then became necrotic and progressed inward from the margins. Symptoms were similar to those reported by Little et al. (3) on basil affected by Pseudomonas viridiflava. Bacteria consistently isolated from leaf lesions formed mucoid colonies with a green fluorescent pigment on King's B medium. Strains were gram negative. In LOPAT (levan-oxidase-potato rot-arginine dihydrolase-tobacco hypersensitivity) tests (2), all induced a hypersensitive reaction (HR) in tobacco (Nicotiana tabacum L. cv. White Burley) leaves (1), caused soft rot of potato tuber slices, and were negative for levan, oxidase, and arginine dihydrolase. Biochemical tests, API 20NE and API 50 CH (Biomérieux, Marcy l'Etoile, France), were also used for identification. The pathogenicity of three isolates was tested twice by injecting 20-day-old healthy basil plants with a bacterial suspension (107 CFU/ml). Controls were injected with sterile distilled water. Plants were kept at 25 to 28°C and 80 to 100% relative humidity. Forty-eight hours after inoculation, dark brown-to-black lesions were observed only on inoculated plants. The bacterium was reisolated from lesions of all plants tested, fulfilling Koch's postulates. No lesions were observed on controls. To identify the pathogen, a PCR technique was used. The 16SrDNA region was amplified with general bacterial primer pair (63f forward and 1389r reverse) (4) then the PCR products were cloned into Escherichia coli DH5α cells and a recombinant plasmid was sequenced by M13 forward and reverse primers. The sequence was deposited in GenBank (Accession No. HE585219). On the basis of the symptoms, biochemical tests, and 16SrDNA sequence homology (99% sequence similarity with a number of P. viridiflava isolates), the pathogen was identified as P. viridiflava. To our knowledge, this is the first report of bacterial leaf spot of basil in Hungary, which can seriously affect the basil production. References: (1) Z. Klement. Nature 199:299, 1963. (2) R. A. Lelliot et al. Appl. Bacteriol. 29:470, 1966. (3) E. L. Little et al. Plant Dis. 78:831, 1994. (4) A. M. Osborn et al. Environ. Microbiol. 2:39, 2000.

Isolation and activity of Xenorhabdus antimicrobial compounds against the plant pathogens Erwinia amylovora and Phytophthora nicotianae.

AIMS: Broad-spectrum antibiotics produced by symbiotic bacteria [entomopathogenic bacterium (EPB)] of entomopathogenic nematodes keep monoxenic conditions in insect cadavers in soil. This study evaluated antibiotics produced by EPB for their potential to control plant pathogenic bacteria and oomycetes. METHODS AND RESULTS: Entomopathogenic bacterium produce antibiotics effective against the fire blight bacterium Erwinia amylovora, including streptomycin resistant strains, and were as effective in phytotron experiments as kasugamycin or streptomycin. Xenorhabdus budapestensis and X. szentirmaii antibiotics inhibited colony formation and mycelial growth of Phytophthora nicotianae. From X. budapestensis, an arginine-rich fraction (bicornutin) was adsorbed by Amberlite((R)) XAD 1180, and eluted with methanol : 1 n HCI (99 : 1). Bicornutin inactivated zoospores, and inhibited germination and colony formation of cystospores at <<25 ppm. An UV-active molecule (bicornutin-A, MW = 826), separated by HPLC and thin-layer chromatography, was identified as a novel hexa-peptide : RLRRRX. CONCLUSIONS: Xenorhabdus budapestensis produces metabolites with strong antibacterial and cytotoxic activity. Individual compounds can be isolated, identified and patented, but their full antimicrobial potential may be multiplied by synergic interactions. SIGNIFICANCE AND IMPACT OF THE STUDY: Active compounds of two new Xenorhabdus species might control plant diseases caused by pathogens of great importance to agriculture such as Erw. amylovora and P. nicotianae.

First Report of Bacterial Fruit Blotch of Watermelon Caused by Acidovorax avenae subsp. citrulli in Hungary.

Typical bacterial fruit blotch (BFB) symptoms were observed on cvs. Crisby, Suzy, Top Gun, and Lady watermelon (Citrullus lanatus (Thunb.) Matsum. & Nakai.) fruits in southeastern Hungary (Medgyesegyháza) in July 2007 when the mean maximum daytime temperature was greater than 32°C. Approximately 20 to 30 ha of watermelons were observed to be affected by the disease. Source of the infection was not determined, however, grafted watermelon transplants that were grown in this area had been imported from Turkey where the pathogen is present (2). Disease symptoms started with irregularly shaped, water-soaked lesions on the surface of the fruits. The lesions enlarged and the epidermis became brown and cracked. BFB symptoms were not readily visible on mature foliage. Colonies of the BFB pathogen were creamy white on nutrient agar (Difco, Detroit, MI). Strains were gram negative, oxidase positive, and produced acid from glucose aerobically. A cell suspension (50 µl of ~1 × 107 CFU/ml) from a 24-h nutrient plate culture was infiltrated with a hypodermic syringe into the intercellular spaces of fully developed intact tobacco (Nicotiana tabacum L. cv. White Burley) leaves to determine the hypersensitive reaction (HR) (1). A typical HR developed 20 h after leaf infiltration. Bacterial pathogenicity was tested on surface-sterilized, mature fruits of different plant species by injecting cell suspensions into the fruit tissues as previously described (each fruit was injected in five places; the negative control (sterile water) as well). Fruits were incubated for 7 days at 25°C and then observed for symptom development. Necrosis was observed at each point of inoculation with the pathogen for watermelon and green pepper (Capsicum annuum L.). Necrosis was also observed for cucumber (Cucumis sativus L.), zucchini (Cucurbita pepo L. convar. giromontiina Greb.), squash (C. pepo L.), and patisson (C. pepo L. convar. patissoniana Greb.). Necrosis was not observed when the pathogen was inoculated onto fruit of melon (Cucumis melo L.), tomato (Lycopersicon esculentum Mill.), and eggplant (Solanum melongena L.). Additionally, symptoms were not observed at the points inoculated with sterile water (negative control) for any of the fruits tested. To identify the pathogen, PCR was used with Acidovorax avenae subsp. citrulli-specific primers WFB1/2 (4). The 16s rDNA region amplified with a general bacterial primer pair (63f forward and 1389r reverse) (3) was cloned into a pBSK+ vector (Stratagene, La Jolla, CA) and sequenced by M13 forward and reverse primers (GenBank Accession No. AM850114). On the basis of the symptoms, biochemical tests (API 20NE; Biomérieux, Marcy l'Etoile, France), fatty acid methyl ester analysis (74.5 to 83.6% similarity), and 16SrDNA sequence homology (100% sequence similarity with AAC00-1), the pathogen was identified as A. avenae subsp. citrulli. To our knowledge, this is the first report of BFB of watermelon in Hungary. References: (1) Z. Klement. Nature 199:299, 1963. (2) M. Mirik et al. Plant Dis. 6:829, 2006. (3) A. M. Osborn et al. Environ. Microbiol. 2:39, 2000. (4) R. R. Walcott and R. D. Gitaitis. Plant Dis. 84:470, 2000.