Ae et l. JA Clinicl Reports (2018) 4:61 https://doi.org/10.1186/s40981-018-0197-7 CLINICAL RESEARCH ARTICLE Open Access Bcteril contmintion upon the opening of injection needles Shintro Ae 1, Iso Hrg 2*, Fumiki Kiyomi 3, Hitomi Kumno 1, Akir Gohr 1, Shigehiro Mtsumoto 1 nd Ken Ymur 1 Astrct Introduction: Two opening methods re used for injection needle products: the peel-prt method where the dhesive surfce of the pckging mount is peeled off, nd the push-off top method, where the needle hu is pressed ginst the mount to rek it. However, the risks of cteril contmintion s result of opening method remin unknown. The im of our study ws to evlute the cteril contmintion of needle hus upon the opening of injection needles y the peel-prt or push-off top method under vrious conditions. Methods: Bcteril contmintion upon the opening of injection needles ws exmined in two mterils, pper nd plstic. Vrious concentrtions of Stphylococcus ureus were pplied to the mount nd were mintined under wet or dry conditions. Injection needles were opened using the peel-prt or push-off top method. Needle hu contmintion ws exmined using gr medium colony counting. Cliniclly ssumed conditions (the hnds nd sliv of nesthesiologists) were lso evluted. Dt were sttisticlly exmined using the Cochrn-Mntel- Henszel, Jonckheere, nd Fisher s exct tests. Results: The lterl surfces of needle hus were contminted using the push-off top method, ut not y the peelprt method, in mnner tht ws dependent on S. ureus concentrtions. No significnt differences were oserved etween mount mterils. Needle hu contmintion ws significntly more severe for the wet thn for the dry opening portion. The cliniclly ssumed condition study reveled tht the lterl nd ottom surfces of the needle hu were contminted significntly more in the sliv contmintion group thn in the dry nd wet hnd groups. Conclusions: The cteril contmintion of needle hus my occur upon the opening of injection needles when the push-off top method is used nd my e ffected y hnds contminted with sliv under clinicl conditions. Keywords: Infection control, Ctheter infection, Needle, Stphylococcus ureus Bckground Bcteril contmintion in infusion lines cuses sepsis, resulting in prolonged rtificil respirtion nd n extended sty in intensive cre units or hospitls [1, 2]. The vlves of infusion lines or syringes for drug injection re involved in cteril contmintion of infusion lines [3, 4]. Injection needles, which re used to spirte drug solutions, my contminte infusion lines through syringes when the syringes re contminted with cteri [5]. The present study focused on the contmintion of needle hus. * Correspondence: hrg@fukuok-u.c.jp 2 Deprtment of Anesthesi, Fukuok University Chikushi Hospitl, 1-1-1 Zokumyouin, Chikushino-shi, Fukuok 818-8502, Jpn Full list of uthor informtion is ville t the end of the rticle Methods Opening methods Two injection needle product opening methods were employed: the peel-prt method (Fig. 1) where the dhesive surfce of the mount for pckging is peeled off, nd the push-off top method (Fig. 1) where the needle hu is pressed ginst the mount to rek it [5]. Bcteril strins nd preprtion of cteril solutions The methicillin-susceptile Stphylococcus ureus strin of the Americn Type Culture Collection (ATCC) 29213 ws used [6]. ATCC 29213 ws provided y the Kitsto University-Lortory of Infection Control nd Reserch Center. A cteril solution ws cultured for 10 h with shking nd ws diluted with physiologicl sline to n The Author(s). 2018 Open Access This rticle is distriuted under the terms of the Cretive Commons Attriution 4.0 Interntionl License (http://cretivecommons.org/licenses/y/4.0/), which permits unrestricted use, distriution, nd reproduction in ny medium, provided you give pproprite credit to the originl uthor(s) nd the source, provide link to the Cretive Commons license, nd indicte if chnges were mde.
Ae et l. JA Clinicl Reports (2018) 4:61 Pge 2 of 6 Fig. 1 Opening methods. Peel-prt method: opening y peeling the dhered plnes of the lister nd mount. Push-off top method: opening y pressing the needle hu to the mount nd reking it. The rrow indictes the prt t which the cteril suspension ws pplied sornce of 0.3 using n sorption spectrometer t 578 nm [7]. The concentrtion of the cteril suspension ws 10 8 colony-forming units/ml (CFUs/ml) efore the experiment. This solution ws diluted with physiologicl sline to six different concentrtions (10 8, 10 7, 10 6,10 5,10 4, nd 10 3 CFUs/ml). Experimentl contmintion of mounts A totl of 240 injection needles, including 120 ech dherently pckged with pper-mount nd trnsprent plstic lister (18G: Terumo Co., Ltd., Tokyo, Jpn) or with plstic (comintion of polystyrene nd polyethylene terephthlte) mount nd trnsprent plstic lister (18G: NIPRO Co., Ltd., Osk, Jpn) were used. The injection needle ws tken out of the ox just efore the initition of experiments nd ws stored on clen ench fter disinfection. Injection needles were clssified into two groups ccording to the opening methods: the peel-prt nd push-off top methods (60 needles ech). Experiments were conducted seprtely for 10 needles ech t six different concentrtions of the cteril suspension. To ssess the risk of needle contmintion y vrious quntittive concentrtions under clinicl settings, 10 μl of ech of the cteril suspensions (10 8, 10 7, 10 6, 10 5, 10 4, nd 10 3 CFUs/ml) ws pplied to the prt ner the needle hu s opening t the mount of n unopened injection needle product using pipette tip on clen ench (shded prts in Fig. 1, ). Using the peel-prt method, the cteril suspension ws pplied to the gripped prt of the mount (shded prts in Fig. 1). Using the push-off method, the cteril suspensions were pplied to the prt potentilly touching the mount when removing theneedle(shdedprtsinfig.1). Injection needles were then opened using the peel-prt or push-off top method with disinfected gloves (Fig. 1, ). On clen ench, hlf of the needles were opened s soon s the cteril suspensions hd een pplied (wetness group). The other hlf were dried using the filtering irflow of the clen ench t room temperture. One hour lter, the dry stte of suspensions pplied ws confirmed visully nd needles were then opened on the clen ench (dryness group). Injection needles were tken out to exmine the degree of contmintion in ech prt of the needle hu. To exmine the degree of contmintion on ech site of the needle hu (Fig. 2), ll lterl surfces (Fig. 2) were plced on gr medium nd rotted to e rought into contct with the medium. The ottom surfce of the needle hu (Fig. 2) ws then pressed ginst the gr medium. To exmine contmintion in the inner lumen (Fig. 2c), 1-ml syringe contining 0.1 ml of sline ws connected to the needle to dischrge ll sline onto the gr medium. The gr medium ws incuted t 37 C for 30 h for colony counting. Brin hert infusion gr (Becton, Dickinson, nd Compny, USA) ws used s the gr medium. Emulted clinicl contmintion (hnd nd sliv contmintion of mounts) Bsed on the rre occurrence of needle hu contmintion in the previous experiment using the peel-prt method, vrious conditions (i.e., dry or wet hnds, sliv contmintion) were exmined to evlute the clinicl risk of needle hu contmintion using the push-off top method. Five nesthesiologists were included in the present study. This investigtion ws conducted in ccordnce with the current Declrtion of Helsinki. The uthors own smples were collected, nd ptients nd volunteers were not included. All smples were nonymized fter collection for the impossiility to identify the specific individul. A totl of 150 injection needles, including 75 ech in the pper-mount group nd plstic-mount group, were used. Fig. 2 Contmintion ws evluted in ech region of the needle hu. Lterl surfce. Bottom surfce. c Inner lumen c
Ae et l. JA Clinicl Reports (2018) 4:61 Pge 3 of 6 Anesthesiologists rued dry/wet hnds on the pper or plstic-mounts without gloves. To simulte wet hnds, 10 μl of utoclved physiologicl sline ws pplied to dry hnds using micropipette. To simulte hnd contminted with ptient s sliv, gloved fingers licked y nesthesiologists were pplied to ech pper nd plstic-mount. Five sliv smples were otined from ech of the five nesthesiologists nd were quntittively cultured. All injection needle products with cliniclly contminted mounts were opened on clen ench in the sme mnner s descried for exmintion of the experimentl contmintion of mounts. Sttisticl nlysis The numers of cteri on the lterl surfces, ottom surfces, nd totl surfce (sum of the lterl surfce, ottom surfce, nd inner lumen) of needle hus were compred etween the opening methods, dryness/wetness of cteril solution, nd mount mterils using the Cochrn-Mntel-Henszel test considering the concentrtion of S. ureus s strtum. By compring the dryness/wetness of cteril solution nd mount mterils, only dt otined using the push-off top method ws used ecuse only one needle hu ws contminted in the peel-prt method. The trend test for the concentrtion of S. ureus-contmintion reltionship ws performed using the push-off top method dt with the Jonckheere test. The numer of cteri in the inner lumen of needle hu ws clssified into contminted ( 1 colony) or uncontminted (no colony), nd this inry response ws compred etween opening methods, the dryness/wetness of the cteril solution, nd mount mterils using Fisher s exct test without considering the concentrtion of S. ureus. A trend test for the S. ureus concentrtion-contmintion reltionship in the numerofcteriintheinnerlumenwsnotperformed ecuse of only five hus were contminted. Fisher s exct test ws insted pplied to compre S. ureus concentrtions. Regrding emulted clinicl contmintion dt, the numer of cteri ws compred etween mounts using the Cochrn-Mntel Henszel test considering the nesthesiologist nd wet/sliv hnds s strt, excluding dry hnd dt ecuse ll were zero. The numers of cteri on the lterl surfces, ottom surfces, inner lumens, nd totl surfce of needle hus were compred etween dry/wet/sliv hnds using the Cochrn-Mntel-Henszel test considering nesthesiologist s strtum. The mount ws not included into strtum ecuse lrge p vlue ws otined for the mount comprison. Pirwise comprisons were lso performed. The fmily-wise error rte ws controlled using the closed testing procedure; first, dt ws compred etween dry, wet, nd sliv hnds with significnce level of 5% nd the testing procedure ws stopped if not significnt. Second, pirwise comprisons were performed with significnce level of 5% for ech test if the first step ws significnt. A p vlue of < 0.05 ws considered to e significnt. Dt were nlyzed using SAS version 9.4 (SAS Institute, Cy, North Crolin, USA). Results Opening methods The lterl nd ottom surfces of needle hus were contminted significntly more y the push-off top method thn y the peel-prt method (Figs. 3, ). However, contmintion of the inner lumen did not significntly increse (Fig. 3c). S. ureus concentrtions Using the push-off top method, contmintion of the needle hu incresed with the concentrtion of S. ureus pplied to the opening portions. Contmintion of the needle hu ws rre t concentrtion of 10 4 CFUs/ml. The numer of contminted needle hus ws 5% (1 out of 20 needles) t concentrtion of 10 4 CFUs/ml, nd 0% (0 out of 20 needles) t concentrtion of 10 3 CFUs/ml. Wet/dry Contmintion of the needle hu ws significntly greter in the wet thn in the dry opening portions (Fig. 4). Pper/plstic No significnt differences were noted in the needle hu contmintion etween mount mterils (pper nd plstic) (Fig. 4). Emulted clinicl contmintions (hnd nd sliv contmintion of mounts) No significnt differences were oserved in the needle hu contmintion etween the dry nd wet hnd contmintion groups (Fig. 5 c). The lterl nd ottom surfces of the needle hu were contminted significntly more in the sliv contmintion group thn in the dry nd wet hnd groups (Fig. 5, ). However, contmintion of the inner lumen did not significntly increse (Fig. 5c). No significnt differences were oserved in the emulted clinicl contmintion of the needle hu etween mount mterils (pper nd plstic) (Fig. 5d). The men cteril concentrtion of the sliv of five nesthesiologists ws 2.36 10 7 CFUs/ml (rnging etween 2.2 10 6 nd 6.1 10 7 CFUs/ml). Discussion The present results showed tht the risk of cteril contmintion ws higher with the push-off top method
Ae et l. JA Clinicl Reports (2018) 4:61 Pge 4 of 6 c Fig. 3 Contmintion of the lterl surfce of the needle hu. Contmintion of the ottom surfce of the needle hu. c Contmintion of the inner lumen of the needle hu. Regrding () nd (), the Cochrn-Mntel-Henszel test considering the concentrtion of S. ureus s strtum ws used to compre etween opening methods. The Jonckheere test ws performed to evlute the concentrtion of the S. ureus-contmintion reltionship for the push-off top method dt nd ws not performed for the peel-prt method ecuse only one needle hu ws contminted. Regrding (c), since fewer contminted needle hus were oserved, the numer of cteri ws clssified into contminted/uncontminted, nd Fisher s exct test ws used to compre opening methods thn with the peel-prt method. Needle products re opened without contct etween cterilly contminted mounts nd sterile needle hus using the peel-prt method. However, needle products re opened due to rupture y pressing the needle hu to the mount using the push-off top method. The contminted lterl nd ottom surfces of needle hus ppered to e ttriuted to contct etween cterilly contminted mounts nd sterile needle hus. We exmined the type of cteri tht cuses cteril contmintion s relted fctor. We used S. ureus in the present study ecuse it is one of the most frequently isolted pthogens from the epidermis nd centrl line-ssocited loodstrem infections [8, 9]. Fig. 4 Contmintion of the needle hu in the push-off top method (wet/dry). Contmintion of the needle hu in the push-off top method (pper/plstic)
Ae et l. JA Clinicl Reports (2018) 4:61 Pge 5 of 6 Fig. 5 Contmintion of the lterl surfce of the needle hu in the push-off top method (dry/wet/sliv). Contmintion of the ottom surfce of the needle hu in the push-off top method (dry/wet/sliv). c Contmintion of the inner lumen of the needle hu in the push-off top method (dry/wet/sliv). d Contmintion of the needle hu in the push-off top method (pper/plstic). All cteril dt otined under dry nd wet conditions were zero, nd, thus, sttisticl test ws not performed. The closed testing procedure ws used. First, dt ws compred etween dry, wet, nd sliv hnds with significnce level of 5%, nd if not significnt, we concluded tht there re no significnt differences for ny pirwise comprisons nd stopped the testing procedure. Second, pirwise comprisons were performed with significnce level of 5% for ech test if the first step ws significnt. Three group comprisons were p = 0.0001, 0.0025, 0.3009, 0.0024, nd 0.0122 for the lterl surfce (), ottom surfce (), inner lumen (c), pper-mount (d), nd plstic-mount (d), respectively Therefore, ATCC 29213 ws selected s the stndrd strin ecuse it exhiits n intermedite iofilm formtion ility s n dhesion fctor [10]. Grm-negtive cillus, prticulrly Pseudomons eruginos, is known cuse of ctheter-relted loodstrem infections [9]. As with S. ureus, grm-negtive cilli my lso cuse contmintion of needle while pckge is eing opened. However, we did not include grm-negtive cilli in this study ecuse the ssys used to ssess the iofilm formtion nd response pttern to drying nd wetting in S. ureus cnnot e performed esily in cilli. Future studies re needed in this re. We lso exmined the effects of vrious concentrtions of S. ureus s one of the risk fctors. Contmintion of the lterl nd ottom surfces of the needle hu ws enhnced y incresing concentrtions of S. ureus. However, the inner lumen contmintion did not significntly increse under wet conditions, even t 10 8 CFUs/ml, which is the presumed concentrtion fter exposure to humn sliv [11]. As nother relted risk fctor, we ssessed the dryness or wetness of the cteril solution. Touch contct with wet hnds led to n verge of 6 10 4 microorgnisms trnslocting, wheres dry touch contct resulted in n verge of 8.5 10 2 microorgnisms trnslocting [12]. Plnktonic S. ureus under wet conditions my esily move with the flow of liquid. The minor flow of liquid with n opening my result in the motion of liquid from the surfce of the mount to the needle hu, cusing cteril movement. Bsed on these findings, clinicl conditions were exmined. The cuses of needle contmintion were ssumed to e the nesthesiologist s hnds with or without sliv. Since nesthesiologists hve mny opportunities to touch the introrl sliv of ptient, humn sliv is considered to e colonizing source of puncture sites/ needles [13]. Contminted mounts due to gloved finger with sliv contminted needle hus significntly more thn in the hnd contmintion group. The push-off method incresed cteril concentrtion, nd wet needle mounts nd hnds my ll contriute to needle hu cteril infection. As limittion of the present study, the extrpoltion of our results to clinicl settings must e mde with cution ecuse our model ws rtificil. In the present study, the investigtor who opened the needle mounts ws the sme investigtor who pplied the cteril suspension.
Ae et l. JA Clinicl Reports (2018) 4:61 Pge 6 of 6 Explntions regrding inter-nesthesiologist vritions hve not yet een confirmed, ut inter-nesthesiologist differences need to e considered. Therefore, contmintion my occur due to the peel-prt method. However, the effects of inter-nesthesiologist vritions ppered to e smll ecuse the opening procedure is simple opertion. Further studies with different cteri nd the repeted connection/ disconnection of needles nd syringes re wrrnted. Conclusions These results indicte tht the cteril contmintion risk of the push-off top method my occur upon opening of injection needles nd my e ffected y hnds contminted with sliv under clinicl conditions. Arevitions ATCC: The Americn Type Culture Collection; CFUs: Colony-forming units; G: Guge Acknowledgements The uthors would like to thnk Dr. H. Hnki (Kitsto University, Lortory of Infection Control nd Reserch Center for Infections nd Antimicroils, Jpn) for comments on the mnuscript nd the provision of strin ATCC 29213 nd Nture Reserch Editing Service (http://it.ly/nres-hs) nd Medicl English Service (www.med-english.com) for English lnguge revision. Funding This reserch ws funded y the Deprtment of Anesthesiology, Fukuok University Fculty of Medicine, Fukuok University, Fukuok, Jpn. Avilility of dt nd mterils Plese contct the uthor (IH) for dt requests. It is our policy tht our originl dt re not pulicly shred in principle, ut for the purpose of udits, they re ville from the uthor. Authors contriutions SA, the first uthor, contriuted to writing the mnuscript with the input of ll uthors. IH, the corresponding uthor, contriuted to writing the mnuscript nd designing the reserch. FK, sttisticin, contriuted to the nlysis of the results. HK ssisted with completing the mnuscript. AG nd SM revised the mnuscript for contents relted to the experiments. KY, professor, revised the mnuscript nd is ccountle for ll spects of the work in nesthesi. All uthors red nd pproved the finl mnuscript. Received: 18 June 2018 Accepted: 14 August 2018 References 1. Wrren DK, Qudir WW, Hollenek CS, Elwrd AM, Cox MJ, Frser VJ. Attriutle cost of ctheter-ssocited loodstrem infections mong intensive cre ptients in nonteching hospitl. Crit Cre Med. 2006;34: 2084 9. 2. Blot SI, Depuydt P, Annemns L, Benoit D, Hoste E, De Wele JJ, et l. Clinicl nd economic outcomes in criticlly ill ptients with nosocomil ctheter-relted loodstrem infections. Clin Infect Dis. 2005;41:1591 8. 3. Rupp ME, Sholtz LA, Jourdn DR, Mrion ND, Tyner LK, Fey PD, et l. Outrek of loodstrem infection temporlly ssocited with the use of n intrvsculr needleless vlve. Clin Infect Dis. 2007;44:1408 14. 4. Stucki C, Sutter AM, Fvet J, Bonnry P. Microil contmintion of syringes during preprtion: the direct influence of environmentl clenliness nd risk mnipultions on end-product qulity. Am J Helth Syst Phrm. 2009;66:2032 6. 5. Clrke TN, Humn RP. Contmintion of hypodermic needles in nesthetic prctice. Anesthesi. 1984;39:549 51. 6. Yorgnci K, Krepel C, Weigelt JA, Edmiston CE. In vitro evlution of the nticteril ctivity of three different centrl venous ctheters ginst grm-positive cteri. Eur J Clin Microiol Infect Dis. 2002;21:379 84. 7. Hrg I, Nomur S, Fukmchi S, Ohjimi H, Hnki H, Hirmtsu K, et l. Emergence of vncomycin resistnce during therpy ginst methicillinresistnt Stphylococcus ureus in urn ptient importnce of low-level resistnce to vncomycin. Int J Infect Dis. 2002;6:302 8. 8. O Grdy NP, Alexnder M, Burns LA, Dellinger EP, Grlnd J, Herd SO, et l. Guidelines for the prevention of intrvsculr ctheter-relted infections. Am J Infect Control. 2011;39:S1 34. 9. Nemoto T, Kunishim H, Shimizu G, Hirose M, Ymski Y, Nishisko H, et l. Fctors predicting the cuse nd prognosis of centrl line-ssocited loodstrem infections. J Infect Chemother. 2015;21:118 22. 10. Hrg I, Ae S, Jimi S, Kiyomi F, Ymur K. Incresed iofilm formtion ility nd ccelerted trnsport of Stphylococcus ureus long ctheter during reciprocl movements. J Microiol Methods. 2017;132:63 8. 11. Aoussi T, Hnnig C, Mhncke K, Kryginni L, Wolkewitz M, Hellwig E, et l. Does humn sliv decrese the ntimicroil ctivity of chlorhexidine ginst orl cteri? BMC Res Notes. 2014;7:711. 12. Ptrick DR, Findon G, Miller TE. Residul moisture determines the level of touch-contct-ssocited cteril trnsfer following hnd wshing. Epidemiol Infect. 1997;119:319 25. 13. Ber ET. Post-durl puncture cteril meningitis. Anesthesiology. 2006;105: 381 93. Ethics pprovl nd consent to prticipte This investigtion ws conducted in ccordnce with the current Declrtion of Helsinki. Consent for puliction Not pplicle. Competing interests The uthors declre tht they hve no competing interests. Pulisher s Note Springer Nture remins neutrl with regrd to jurisdictionl clims in pulished mps nd institutionl ffilitions. Author detils 1 Deprtment of Anesthesiology, Fukuok University Fculty of Medicine, 7-45-1 Nnkum, Jonn-ku, Fukuok-shi, Fukuok 814-0180, Jpn. 2 Deprtment of Anesthesi, Fukuok University Chikushi Hospitl, 1-1-1 Zokumyouin, Chikushino-shi, Fukuok 818-8502, Jpn. 3 Sttiticin, Ph.D., Acdemi, Industry nd Government Collortive Reserch Institute of Trnsltionl Medicine for Life Innovtion, Fukuok University, 7-45-1, Nnkum, Jonn-ku, Fukuok-shi, Fukuok 814-0180, Jpn.