Limits...
Neonatal enteral feeding tubes as loci for colonisation by members of the Enterobacteriaceae.

Hurrell E, Kucerova E, Loughlin M, Caubilla-Barron J, Hilton A, Armstrong R, Smith C, Grant J, Shoo S, Forsythe S - BMC Infect. Dis. (2009)

Bottom Line: All the S. marcescens isolates from the enteral feeding tubes were resistant to amoxicillin and co-amoxiclav.Of additional importance was that a quarter of E. hormaechei isolates were resistant to the 3rd generation cephalosporins ceftazidime and cefotaxime.Subsequently, these organisms will enter the stomach as a bolus with each feed.

View Article: PubMed Central - HTML - PubMed

Affiliation: School of Science and Technology, Nottingham Trent University, Clifton Lane, Nottingham, NG11 8NS, UK. edward.hurrell@hotmail.com

ABSTRACT

Background: The objective of this study was to determine whether neonatal nasogastric enteral feeding tubes are colonised by the opportunistic pathogen Cronobacter spp. (Enterobacter sakazakii) and other Enterobacteriaceae, and whether their presence was influenced by the feeding regime.

Methods: One hundred and twenty-nine tubes were collected from two neonatal intensive care units (NICU). A questionnaire on feeding regime was completed with each sample. Enterobacteriaceae present in the tubes were identified using conventional and molecular methods, and their antibiograms determined.

Results: The neonates were fed breast milk (16%), fortified breast milk (28%), ready to feed formula (20%), reconstituted powdered infant formula (PIF, 6%), or a mixture of these (21%). Eight percent of tubes were received from neonates who were 'nil by mouth'. Organisms were isolated from 76% of enteral feeding tubes as a biofilm (up to 107 cfu/tube from neonates fed fortified breast milk and reconstituted PIF) and in the residual lumen liquid (up to 107 Enterobacteriaceae cfu/ml, average volume 250 mul). The most common isolates were Enterobacter cancerogenus (41%), Serratia marcescens (36%), E. hormaechei (33%), Escherichia coli (29%), Klebsiella pneumoniae (25%), Raoultella terrigena (10%), and S. liquefaciens (12%). Other organisms isolated included C. sakazakii (2%),Yersinia enterocolitica (1%),Citrobacter freundii (1%), E. vulneris (1%), Pseudomonas fluorescens (1%), and P. luteola (1%). The enteral feeding tubes were in place between < 6 h (22%) to > 48 h (13%). All the S. marcescens isolates from the enteral feeding tubes were resistant to amoxicillin and co-amoxiclav. Of additional importance was that a quarter of E. hormaechei isolates were resistant to the 3rd generation cephalosporins ceftazidime and cefotaxime. During the period of the study, K. pneumoniae and S. marcescens caused infections in the two NICUs.

Conclusion: This study shows that neonatal enteral feeding tubes, irrespective of feeding regime, act as loci for the bacterial attachment and multiplication of numerous opportunistic pathogens within the Enterobacteriaceae family. Subsequently, these organisms will enter the stomach as a bolus with each feed. Therefore, enteral feeding tubes are an important risk factor to consider with respect to neonatal infections.

Show MeSH

Related in: MedlinePlus

Electron microscopy of enteral feeding tube inner wall from neonate fed breast milk and reconstituted PIF with added thickener. Bar indicates 10 μm size marker.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC2749046&req=5

Figure 4: Electron microscopy of enteral feeding tube inner wall from neonate fed breast milk and reconstituted PIF with added thickener. Bar indicates 10 μm size marker.

Mentions: The same Enterobacteriaceae species were isolated from both the residual liquids and the biofilms. The Enterobacteriaceae isolated were primarily E. cancerogenus (41%), S. marcescens (36%), E. hormaechei (33%), E. coli (29%), K. pneumoniae (25%), and R. terrigena (22%) (see additional file 2). Other organisms isolated less frequently included C. sakazakii from breast milk and ready to feed formula groups, and a single isolate of Y. enterocolitica from the reconstituted PIF group. E. cancerogenus, S. marcescens, and E. hormaechei and were isolated from all feeding regimes, including the 'nil by mouth' cohort (see additional file 2). The E. hormaechei and E. cancerogenus (identified by16S rDNA sequence analysis) were presumptively identified as E. cloaceae and K. oxytoca, respectively, by phenotypic profiling. Non-Enterobacteriaceae which were isolated from VRBGA included P. fluorescens, P. luteola and Chromobacterium violaceum. Electron microscopy of enteral feeding tube inner wall revealed that a dense, and morphologically diverse flora was present (Fig 3 and 4). This included a variety of short and long rod-shaped bacteria; some with tapering ends (Fig. 3). Yeast size cells were also visible (Fig. 4). Preliminary experiments with direct plating of enteral tube material on non-selective agar isolated staphylococci, lactic acid bacteria and Candida albicans (data not shown). Since these were not the focus of the study, they were not investigated further. There was no significant difference in the proportion of samples positive for Enterobacteriaceae between the feeding regimes (chi-square = 7.82, 5DF, P > 0.05). The distribution of bacterial species was different in tubes from 'nil by mouth' samples compared with all other regimes added together (chi-square = 16.28, 7DF P < 0.05). After removing the 'nil by mouth' samples from the statistical analysis, there were highly significant differences in the distribution of isolates between feeding regimes (chi-square = 94.95, 28DF, P < 0.001). Comparing each feeding regime with each of the others, showed that the breast milk and mixed feeding regimes were the only two giving similar distribution of isolates (chi-square = 9.72, 7DF, P > 0.05). Each of the other feeding regimes has a unique distribution of bacterial isolates.


Neonatal enteral feeding tubes as loci for colonisation by members of the Enterobacteriaceae.

Hurrell E, Kucerova E, Loughlin M, Caubilla-Barron J, Hilton A, Armstrong R, Smith C, Grant J, Shoo S, Forsythe S - BMC Infect. Dis. (2009)

Electron microscopy of enteral feeding tube inner wall from neonate fed breast milk and reconstituted PIF with added thickener. Bar indicates 10 μm size marker.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2749046&req=5

Figure 4: Electron microscopy of enteral feeding tube inner wall from neonate fed breast milk and reconstituted PIF with added thickener. Bar indicates 10 μm size marker.
Mentions: The same Enterobacteriaceae species were isolated from both the residual liquids and the biofilms. The Enterobacteriaceae isolated were primarily E. cancerogenus (41%), S. marcescens (36%), E. hormaechei (33%), E. coli (29%), K. pneumoniae (25%), and R. terrigena (22%) (see additional file 2). Other organisms isolated less frequently included C. sakazakii from breast milk and ready to feed formula groups, and a single isolate of Y. enterocolitica from the reconstituted PIF group. E. cancerogenus, S. marcescens, and E. hormaechei and were isolated from all feeding regimes, including the 'nil by mouth' cohort (see additional file 2). The E. hormaechei and E. cancerogenus (identified by16S rDNA sequence analysis) were presumptively identified as E. cloaceae and K. oxytoca, respectively, by phenotypic profiling. Non-Enterobacteriaceae which were isolated from VRBGA included P. fluorescens, P. luteola and Chromobacterium violaceum. Electron microscopy of enteral feeding tube inner wall revealed that a dense, and morphologically diverse flora was present (Fig 3 and 4). This included a variety of short and long rod-shaped bacteria; some with tapering ends (Fig. 3). Yeast size cells were also visible (Fig. 4). Preliminary experiments with direct plating of enteral tube material on non-selective agar isolated staphylococci, lactic acid bacteria and Candida albicans (data not shown). Since these were not the focus of the study, they were not investigated further. There was no significant difference in the proportion of samples positive for Enterobacteriaceae between the feeding regimes (chi-square = 7.82, 5DF, P > 0.05). The distribution of bacterial species was different in tubes from 'nil by mouth' samples compared with all other regimes added together (chi-square = 16.28, 7DF P < 0.05). After removing the 'nil by mouth' samples from the statistical analysis, there were highly significant differences in the distribution of isolates between feeding regimes (chi-square = 94.95, 28DF, P < 0.001). Comparing each feeding regime with each of the others, showed that the breast milk and mixed feeding regimes were the only two giving similar distribution of isolates (chi-square = 9.72, 7DF, P > 0.05). Each of the other feeding regimes has a unique distribution of bacterial isolates.

Bottom Line: All the S. marcescens isolates from the enteral feeding tubes were resistant to amoxicillin and co-amoxiclav.Of additional importance was that a quarter of E. hormaechei isolates were resistant to the 3rd generation cephalosporins ceftazidime and cefotaxime.Subsequently, these organisms will enter the stomach as a bolus with each feed.

View Article: PubMed Central - HTML - PubMed

Affiliation: School of Science and Technology, Nottingham Trent University, Clifton Lane, Nottingham, NG11 8NS, UK. edward.hurrell@hotmail.com

ABSTRACT

Background: The objective of this study was to determine whether neonatal nasogastric enteral feeding tubes are colonised by the opportunistic pathogen Cronobacter spp. (Enterobacter sakazakii) and other Enterobacteriaceae, and whether their presence was influenced by the feeding regime.

Methods: One hundred and twenty-nine tubes were collected from two neonatal intensive care units (NICU). A questionnaire on feeding regime was completed with each sample. Enterobacteriaceae present in the tubes were identified using conventional and molecular methods, and their antibiograms determined.

Results: The neonates were fed breast milk (16%), fortified breast milk (28%), ready to feed formula (20%), reconstituted powdered infant formula (PIF, 6%), or a mixture of these (21%). Eight percent of tubes were received from neonates who were 'nil by mouth'. Organisms were isolated from 76% of enteral feeding tubes as a biofilm (up to 107 cfu/tube from neonates fed fortified breast milk and reconstituted PIF) and in the residual lumen liquid (up to 107 Enterobacteriaceae cfu/ml, average volume 250 mul). The most common isolates were Enterobacter cancerogenus (41%), Serratia marcescens (36%), E. hormaechei (33%), Escherichia coli (29%), Klebsiella pneumoniae (25%), Raoultella terrigena (10%), and S. liquefaciens (12%). Other organisms isolated included C. sakazakii (2%),Yersinia enterocolitica (1%),Citrobacter freundii (1%), E. vulneris (1%), Pseudomonas fluorescens (1%), and P. luteola (1%). The enteral feeding tubes were in place between < 6 h (22%) to > 48 h (13%). All the S. marcescens isolates from the enteral feeding tubes were resistant to amoxicillin and co-amoxiclav. Of additional importance was that a quarter of E. hormaechei isolates were resistant to the 3rd generation cephalosporins ceftazidime and cefotaxime. During the period of the study, K. pneumoniae and S. marcescens caused infections in the two NICUs.

Conclusion: This study shows that neonatal enteral feeding tubes, irrespective of feeding regime, act as loci for the bacterial attachment and multiplication of numerous opportunistic pathogens within the Enterobacteriaceae family. Subsequently, these organisms will enter the stomach as a bolus with each feed. Therefore, enteral feeding tubes are an important risk factor to consider with respect to neonatal infections.

Show MeSH
Related in: MedlinePlus