Open Access

Surveillance of surgical site infections by Pseudomonas aeruginosa and strain characterization in Tanzanian hospitals does not provide proof for a role of hospital water plumbing systems in transmission

  • Nyambura Moremi1, 2Email author,
  • Heike Claus1,
  • Ulrich Vogel1 and
  • Stephen E. Mshana2
Antimicrobial Resistance & Infection Control20176:56

https://doi.org/10.1186/s13756-017-0216-x

Received: 2 April 2017

Accepted: 30 May 2017

Published: 6 June 2017

Abstract

Background

The role of hospital water systems in the development of Pseudomonas aeruginosa (P. aeruginosa) surgical site infections (SSIs) in low-income countries is barely studied. This study characterized P. aeruginosa isolates from patients and water in order to establish possible epidemiological links.

Methods

Between December 2014 and September 2015, rectal and wound swabs, and water samples were collected in the frame of active surveillance for SSIs in the two Tanzanian hospitals. Typing of P. aeruginosa was done by multi-locus sequence typing.

Results

Of 930 enrolled patients, 536 were followed up, of whom 78 (14.6%, 95% CI; 11.6–17.5) developed SSIs. P. aeruginosa was found in eight (14%) of 57 investigated wounds. Of the 43 water sampling points, 29 were positive for P. aeruginosa. However, epidemiological links to wound infections were not confirmed. The P. aeruginosa carriage rate on admission was 0.9% (8/930). Of the 363 patients re-screened upon discharge, four (1.1%) possibly acquired P. aeruginosa during hospitalization. Wound infections of the three of the eight P. aeruginosa SSIs were caused by a strain of the same sequence type (ST) as the one from intestinal carriage. Isolates from patients were more resistant to antibiotics than water isolates.

Conclusions

The P. aeruginosa SSI rate was low. There was no evidence for transmission from tap water. Not all P. aeruginosa SSI were proven to be endogenous, pointing to other routes of transmission.

Keywords

P. aeruginosa Surgical site infectionWater microbiologyTanzania

Background

Pseudomonas aeruginosa (P. aeruginosa) has emerged as an important opportunistic pathogen [1]. P. aeruginosa is mostly found in moist environments including hospital water systems [2, 3]. Its ability of forming biofilms contributes to its persistence in water system [4] hence a potential reservoir for Pseudomonas surgical site infections. Wound infections especially caused by multidrug-resistant P. aeruginosa strains are associated with increased morbidity and mortality [5].

Colonization of hospital water plumbing systems with P. aeruginosa has been shown to be an important source of the bacteria facilitating transmission to patients [6, 7]. Other sources such as contamination by P. aeruginosa of healthcare workers’ hands [8] and patient’s P. aeruginosa intestinal carriage [9] have been established to be other potential routes of transmission. The proportion of P. aeruginosa among other bacteria causing wound infections in Tanzania has been reported to be 16.3% (2014) at Muhimbili National Hospital [10] and between 27% (2014) and 40% (2016) at the Bugando Medical Centre (BMC) [11, 12]. In both hospitals, P. aeruginosa was found to contribute significantly to wound infections. Despite the fact that surgical site infections (SSIs) is among global burdens which requires priority [13], routine surveillance as an infection control measure [14] is not done in most low income countries.

In this study we conducted surveillance of SSIs at a Tanzanian regional and a tertiary hospital to assess the burden of SSI and to specifically link P. aeruginosa SSI to asymptomatic carriage and hospital water in order to determine the source.

Methods

Study design and setting

A prospective cohort study was conducted between December 2014 and September 2015 at Sekou Toure and BMC hospitals in the Mwanza region. Sekou Toure is a regional referral hospital with a bed capacity of 300. The BMC is a tertiary referral hospital for 10 out of 30 regions of Tanzania, which has a bed capacity of 1000 and serves about 18 million people. A total of 930 patients who were admitted for surgery (general surgery, obstetrics, gynaecology and orthopaedic) at the two hospitals within the study period were enrolled into the study after signing a written informed consent. Their socio-demographic information and medical history relevant to the study were recorded.

Infection surveillance

Rectal swabs were taken using sterile Amies swabs (Mast Group Ltd., United Kingdom) within 48 h of admission (before surgery), and on discharge to assess P. aeruginosa carriage status. On admission carriage was defined as a positive screening culture within 48 h of being admitted to the hospital in absence of positive clinical specimen [15, 16]. On discharge carriage was defined as a positive screening culture when the patient was discharged from the hospital. Hospital acquired carriage was considered when a strain of P. aeruginosa was not detected upon admission screening or in case of acquisition of a strain of P. aeruginosa with a different sequence type (ST) during hospital stay on discharge.

Patients were followed up by either a surveillance doctor or a trained nurse after surgery to register signs and types of SSI according to NHSN definitions [15]. In case of clinical SSI, a surveillance doctor or a trained nurse took swabs for microbiological investigation. Surveillance doctor’s mobile phone number was given to discharged patients to notify the doctor in case they noted any signs or symptoms of SSI. The total surveillance period was until either a SSI became apparent or up to 30 days after being operated. Patients who underwent orthopaedic surgeries including foreign body implantation were followed-up for 90 days. Text messages were sent to patients every other day to remind them to notify a surveillance doctor when they noted any signs or symptoms of SSI.

Water sampling

Sekou Toure hospital receives its water from a deep drilled well within the hospital compound which is locally chlorinated before being used, whereas BMC hospital receives water from Lake Victoria treated by a modern Capri-point Water Treatment Plant and therefore not locally chlorinated as a routine. The aim of this study was to investigate hospital water used routinely by staff and patients without applying any intervention so as to match recovered P. aeruginosa isolates with patients’ isolates.

Three water taps were identified for cold water sampling as per above explained purposes in each of the 11 wards where patients were enrolled. In addition, operating theatres and main water distribution points were sampled. In total 16 and 27 sampling points were defined in Sekou Toure and BMC hospitals, respectively. Water samples were collected as per DIN EN ISO 19458 (water sampling for microbiological analysis) monthly for up to 10 months in BMC and for four months in Sekou Toure hospital. Water sampling according to purposes A, B, and C was performed as outlined in the international standard EN/ISO 19458:2006 [17] with the aim of assessing the quality of water at the point of delivery to the hospital to rule out contamination from other sources outside hospital premises (purpose A), the quality of the waterlines supplying the taps (purpose B), and the possible contamination of the taps themselves (purpose C). The main difference between purposes A and B is the water volume discarded to flush the disinfectant before sampling, which was 10 L for purpose A and 1.5 L for purpose B. In contrast to purposes A and B, the sampling points were not disinfected for purpose C. A 125 ml-sampling bottle containing sodium thiosulfate (final concentration in the water sample: 20 mg/l) was used. At the Sekou Toure hospital sampling was solely conducted according to purpose C due to the aforementioned nature of water source.

A double-concentrated malachite base (Merck Millipore, Germany) was prepared and when cooled was supplemented with malachite-green oxalate solution (final concentration of 0.02 g/l). Malachite green broth enrichment was used to investigate the presence of P. aeruginosa in water [18], because filtration of water or alternative most probable number approaches required technical equipment not available on site.

Isolation of P. aeruginosa from water

One hundred millilitres of the collected water were inoculated into the 250 ml glass bottles containing 100 ml of malachite-green broth (final concentration of 0.01gmalachite green oxalate /l) and incubated aerobically at 37 °C for 24 to a maximum of 72 h. In case of turbidity and/ or colour changes from green to yellow, 100 μl was sub-cultured onto blood (BD Difco, USA) and cetrimide (Merck Millipore, Germany) agars. The plates were incubated at 37 °C for 24 h. Yellowish-green colonies on cetrimide agar matching the oxidase positive colonies on blood agar were regarded positive for P. aeruginosa. Identification was confirmed by VITEK-MS (bioMérieux, France), because this was the method of choice also for the patient isolates.

Analysis of P. aeruginosa from patients

Sterile cotton swabs (Mast Group Ltd., United Kingdom) were used to collect rectal and pus/wound swab from patients for carriage and infection purposes, respectively. Gram staining and culture of the pus/wound swab was performed in parallel. Pus/wound and rectal swabs were inoculated onto blood and MacConkey agars (BD Difco, USA), respectively, incubated at 37 °C, and examined for growth after 24–48 h. Oxidase test was performed to all non-lactose fermenting colonies. Oxidase-positive colonies were further analysed by VITEK-MS (bioMérieux, France).

All P. aeruginosa isolates were subjected to antimicrobial susceptibility testing using VITEK-2 system (bioMérieux, France) according to the manufacturer’s recommendations. Isolates with intermediate susceptibility were regarded as resistant in the analysis. The recommendations of EUCAST (http://www.eucast.org/clinical_breakpoints/) were applied for evaluation.

Multilocus sequence typing

Multilocus sequence typing (MLST) using seven housekeeping genes was performed as previously described [19]. The PCR products were sequenced at GATC Biotech AG (Cologne, Germany). Sequence alignment and analysis was done using MegAlign software (DNASTAR Inc. USA) and the P. aeruginosa MLST website http://pubmlst.org/paeruginosa/was used to assign isolates to their respective sequence types (STs).

Carbapenemase gene screening

All four P. aeruginosa isolates with either intermediate or resistant susceptibility to carbapenems were screened for metallo-beta lactamase genes (bla IMP, bla VIM [20], bla GIM, bla NDM, bla SIM, bla SPM and bla OXA-48) [21]as described previously.

Data analysis

Data were analysed using STATA version 13 (STATA Corp LP, USA). Categorical variables were summarized as proportions and were analysed using the Pearson’s Chi-Square test or Fisher’s exact to test statistical differences among the various groups. The two-sample test of proportion was used to calculate 95% confidence interval (CI) and the Mann Whitney ranksum test was performed to compare medians. A p-value of less than 0.05 was considered statistically significant.

Results

Demographics

A total of 930 patients (57.8% female) were enrolled. The BMC tertiary hospital contributed to 64.9% (n = 604). The median age of the participants was 32.1 (range 2 months-83 years). Most patients came from Mwanza (61.9%, n = 576), Mara (10.1%, n = 94) and Shinyanga (8.5%, n = 79) regions. Of the 930 patients screened for P. aeruginosa carriage on admission, 363 were re-screened on discharge. After discharge follow-up was restricted to patients with mobile phones, therefore, 57.6% (536/930) of the enrolled patients were successfully followed-up. The median age (years) of followed-up patients was 26 (IQR: 18–42) while for those not followed-up was 31 (IQR: 23–48), p = 0.0001. Other socio-demographic parameters (sex, hospital, marital status, occupation etc) were equally distributed within the two groups.

SSI rates, types and P. aeruginosa carriage

Of the 536 patients followed-up after discharge, 78 (14.6%, 95% CI; 11.6–17.5) developed SSI. The wounds of 57 patients were investigated microbiologically, of which 50 (87.7%) had significant bacterial growth and eight (14%) were positive for P. aeruginosa. All patients with P. aeruginosa SSI were classified as superficial incisional SSI (A1).

Of the 930 patients screened on admission, eight (0.9%) were found to be colonized with P. aeruginosa as demonstrated by rectal swabs. Of the 363 patients re-screened on discharge, seven (1.9%) were colonized with P. aeruginosa. Of those, four possibly acquired the strain during hospitalization and the remaining three patients were colonized upon admission and discharge.

P. aeruginosa In the water distribution

Cold water samples were taken from taps located in wards as well as in the operating theatres. The mean (±standard deviation) water temperature was 26.2 (±0.4) and 25.8 (±0.8)°C at BMC and Sekou Toure hospitals, respectively. Twenty-two (81.5%) of the 27 water sampling points from BMC hospital were positive for P. aeruginosa throughout the study period; 11 (40.7%) were positive for P. aeruginosa at least twice (Table 1). At BMC hospital, sampling points were positive in the months December 2014 (N = 11), and January (N = 6), August (N = 6) and September (N = 15) 2015, resulting in 38 P. aeruginosa isolates. Seven (44%) of the 16 sampling points from Sekou Toure hospital were positive throughout the study period; only one sampling point was positive more than once resulting in ten isolates (Table 2).
Table 1

Sequence type distribution among Pseudomonas aeruginosa detected at 22 out of 27 sampling points at Bugando Medical Centre hospital

 

Sampling point

Ward/ sampling point category

Sampling plan

Number of P. aeruginosa recovery from water taps in 10 months

Sequency type of P. aeruginosa

1

Main distribution

-

A

2 of 10

381, 2320a

2

OT changing room

Operating Theatre

B

2 of 10

381

3

OT2

Operating Theatre

C

3 of 10

381, 252, 2307a

4

OT3

Operating Theatre

C

1 of 10

381

5

OT5

Operating Theatre

C

1 of 10

381

6

OT sluice

Operating Theatre

C

1 of 10

381

7

LWOT

Maternity Operating Theatre

B

1 of 10

381

8

LW staff WC

Maternity

C

1 of 10

381

9

LW patient WC

Maternity

C

2 of 10

381, 834

10

C4 patient WC

Maternity

C

2 of 10

381, 641

11

C4 sluice

Maternity

C

1 of 10

2327a

12

E4 patient WC

Gynaecology

C

2 of 10

381, 2307a

13

E4 sluice

Gynaecology

C

1 of 10

2325a

14

J5 staff WC

Orthopaedic

B

4 of 10

381, 834, 2307a

15

J5 patient WC

Orthopaedic

C

1 of 10

2326a

16

C6 staff WC

General surgery

B

3 of 10

381, 834

17

C6 patient WC

General surgery

C

1 of 10

381

18

E8 Staff WC

Orthopaedic

B

1 of 10

381

19

E8 patient WC

Orthopaedic

C

3 of 10

381

20

C9 staff WC

General surgery

B

2 of 10

381

21

C9 patient WC

General surgery

C

1 of 10

381

22

C9 sluice

General surgery

C

2 of 10

381, 236

Key: WC: Water Closet (Toilet); aNew ST; bold letters indicate common clone

Table 2

Sequence type distribution among Pseudomonas aeruginosa detected at seven out of 16 total sampling points at Sekou Toure hospital

 

Sampling point

Ward/ sampling point category

Sampling plan

Number of P. aeruginosa recovery from water taps in 4 months

Sequency type of P. aeruginosa

1

Main distribution

-

C

1 of 4

2307 a

2

STGN station

Gynaecology

C

4 of 4

2307 a

3

FW station

Female

C

1 of 4

252

4

MW2 patient WC

Male

C

1 of 4

316

5

LW station

Maternity

C

1 of 4

2307 a

6

OT1

Operating theatre

C

1 of 4

2307 a

7

OT2

Operating theatre

C

1 of 4

2307 a

Key: WC: Water Closet (Toilet); aNew ST; bold letters indicate common clone

Sequence types distribution

A total of 18 different sequence types (STs) was observed among 71 P. aeruginosa isolates of which eight were new STs. Ten STs occurred only once (Table 3). Of the eight patients with P. aeruginosa SSI, four from the BMC hospital harboured the multi-resistant ST235. Two of the four patients with SSI due to P. aeruginosa ST235 were treated in the same ward and developed SSI two days apart. Three patients with SSI harboured strains bearing the same STs as those in their intestines i.e. STs 235, 2309 and 2319 (Table 4). Three patients carried P. aeruginosa isolates that shared STs with isolates recovered from water taps of the wards they were admitted in (Table 4). As shown in Table 3, the overlap of STs of strains from patients and the water distribution was minimal, only STs 2307 and 252 were observed in both hospitals. ST2307 and ST381 were observed in 66.7% (8/12) and in 42.4% (25/59) of isolates from Sekou Toure and BMC hospital, respectively.
Table 3

Sequence type distribution among Pseudomonas aeruginosa isolates from Sekou Toure hospital and Bugando Medical Centre

Sequence type

Sekou Toure hospital

(N = 12)

 

Bugando Medical Centre (N = 59)

 
 

Patients (2)

Water(10)

Patients (21)

Water (38)

2307a

-

8

4

3

2309a

2

-

-

-

2317a

-

-

1

-

2319a

-

-

4

-

2320a

-

-

-

1

2325a

-

-

-

1

2326a

-

-

-

1

2327a

-

-

-

1

235

-

-

6

-

236

-

-

-

1

244

-

-

1

-

252

-

1

-

1

316

-

1

-

-

381

-

-

1

25

399

-

-

3

-

553

-

-

1

-

641

-

-

-

1

834

-

-

-

3

Key: aNew ST; bold letters indicate sequence type identity shared by patients and water samples

Table 4

Possible transmission sources among 17 patients who carried and/or were infected with Pseudomonas aeruginosa

Patient

ID

Age (years)

Sex

Hospital

Ward Category

Type of Surgery

Hospital stay

(days)

P.a. Carriage at Admission

P.a. strain (ST)

P.a. Carriage at Discharge

P. a. strain (ST)

SSI with P. a.

P. a. strain (ST)

P. a. strain (ST) in admitting ward

70

55

M

Bugando

General surgery

Laparotomy

7

Yes

2319a

No

-

No

-

381, 834

93

67

M

Bugando

General surgery

Esophagotomy

2

Yes

2319 a

Yes

2319 a

Yes

2319 a

381, 834

528

26

M

Bugando

General surgery

Laparotomy

18

No

-

No

-

Yes

2317a

381, 834

532

27

M

Bugando

General surgery

Colostomy

6

No

-

Yes

553

No

-

381, 834

323

1

F

Bugando

General surgery

Fistulectomy

8

No

-

Yes

399

No

-

381, 236

436

47

M

Bugando

General surgery

Mastectomy

2

Yes

399

Yes

399

No

-

381, 236

477

63

F

Bugando

General surgery

Mastectomy

2

Yes

381

No

-

No

-

381, 236

GN001

58

F

Bugando

Gynaecology

Laparotomy

10

Yes

2307 a

Yes

2307 a

No

-

381, 2307 a, 2325a

GN002

49

F

Bugando

Gynaecology

Myomectomy

10

No

-

Yes

2307 a

No

-

381, 2307 a, 2325a

GN003

45

F

Bugando

Gynaecology

Laparotomy

4

Yes

2307 a

No

-

No

-

381, 2307, a 2325a

GN026

33

F

Bugando

Gynaecology

Laparotomy

8

No

-

No

-

Yes

244

381, 2307a, 2325a

33

27

M

Bugando

Orthopaedic

ORIF

23

No

-

No

-

Yes

235

381

41

28

M

Bugando

Orthopaedic

ORIF

21

No

-

No

-

Yes

235

381

245

83

M

Bugando

Orthopaedic

ORIF

10

Yes

235

No

-

No

-

381

11

54

F

Bugando

Orthopaedic

ORIF

33

No

-

No

-

Yes

235

381, 834, 2307a, 2326a

LW028

31

F

Bugando

Obstetrics

Csection

3

Yes

235

No

-

Yes

235

381, 834

ST098

30

F

Sekou Toure

Obstetrics

Csection

4

No

-

Yes

2309 a

Yes

2309 a

2307a

Key: P.a; Pseudomonas aeruginosa; SSI; Surgical site infection; ORIF; Open Reduction Internal Fixation; Csection; Caesarean Section; aNew sequence type (ST); bold numbers indicate shared sequence type identity between carried and SSI P. aeruginosa or between carried P. aeruginosa and P. aeruginosa from water samples in the same ward. All 17 patients were followed-up for SSI

Antimicrobial susceptibility

Fifty-six P. aeruginosa isolates were analysed of which 17 were non-repetitive isolates from patients and 39 from water. Only one strain per sequence type (ST) per patient and one strain per ST per sampling point were included in this analysis. All clinical and water isolates were resistant to aztreonam (Table 5). Of patients’ isolates, 41.2% (7/17), 35.3% (6/17) and 17.7% (3/17) were resistant to piperacillin-tazobactam, ceftazidime and meropenem/imipenem, respectively. Higher resistance rates were observed in patients in comparison to water isolates for piperacillin-tazobactam (p = 0.001), ceftazidime (p < 0.001) and amikacin (p = 0.0004). Fosfomycin resistance was significantly more frequent in water isolates than in clinical isolates (61.5% vs. 17.7%, p = 0.001) (Table 5).
Table 5

Resistance rates of Pseudomonas aeruginosa isolates from patients and water

Antimicrobial agent

Patients isolates (17)

Water isolates (39)

P value

 

N (%)

N (%)

 

Amikacin

5 (29.4)

0 (0)

0.0004

Aztreonam

17 (100)

39 (100)

-

Cefepime

1 (5.9)

0 (0)

0.063

Ceftazidime

6 (35.3)

0 (0)

<0.001

Ciprofloxacin

5 (29.4)

6 (15.4)

0.112

Colistin

0 (0)

0 (0)

-

Ertapenem

3 (17.7)

1 (2.6)

0.0256

Fosfomycin

3 (17.7)

24 (61.5)

0.001

Gentamicin

5 (29.4)

5 (12.8)

0.06

Imipinem

3 (17.7)

1 (2.6)

0.0219

Meropenem

3 (17.7)

0 (0)

0.0035

Piperacillin

8 (47.1)

7 (18.0)

0.012

Piperacillin-tazobactam

7 (41.2)

1 (2.6)

0.001

Tobramycin

5 (29.4)

2 (5.1)

0.005

All four isolates with reduced susceptibility to carbapenems were screened for carbapenemase genes, of which none of them tested positive.

Discussion

In this study the rate of P. aeruginosa SSI was low and accounted for a minor proportion of all SSIs. One reason for this might be the low intestinal carriage rate on admission imposing a low risk of endogenous infection [9]. Despite the low number of patients with P. aeruginosa SSI, this study confirmed intestinal carriage as a source of infection in three patients based on MLST typing. As explained previously [22], personal hygiene has been found to contribute to endogenous transmission. This is further supported in the current study by the fact that the three patients with an evidence of endogenous source developed infection after being discharged from the hospital; explaining the possibility of poor hygiene at home during the change of dressing.

In the current study the difference of P. aeruginosa carriage rates upon admission and discharge was not statistically significant. The relative low rate observed on the discharge could be explained by the low yield of a single-time swabbing compared to multiple swabbing [9]. However, as documented previously [23] regarding hospital acquisition of P. aeruginosa, four patients who were negative on admission were found to be colonized upon discharge, indicating possible hospital acquisition of P. aeruginosa.

Out of eight patients with P. aeruginosa SSI, four were found to belong to ST235, a multi-resistant clone, which is widely distributed in European [24, 25] and Asian countries [26, 27]. Unlike previous reports on this international high-risk clone [25, 28, 29], carbapenemase genes such as bla VIM-2 were not identified by PCR. Interestingly, two of the four patients with P. aeruginosa ST235 SSI were spatio-temporally linked; pointing to the possibility of a common source in the ward.

Although more than 80% of the sampled water taps at BMC hospital were at least once positive for P. aeruginosa during the observation period, no clear linkage to P. aeruginosa SSI was established in contrast to what has been reported previously [6]. This observation could be explained by the fact that, the taps were found to be P. aeruginosa free amidst the surveillance period following the intervention such as local chlorination made by the BMC hospital infection control team after seeing preliminary sampling results. This could have affected the link of P. aeruginosa SSI to water system because during the intervention period patients were at risk of getting P. aeruginosa SSI but the exogenous risk (water system colonization) was absent.

Another reason might be the possibility of low bacterial loads. Due to the technique employed in this study, only the presence of P. aeruginosa was detected, but not the quantity. Although the current study could not establish the association between water system and P. aeruginosa SSI, two sequence types (ST381 and ST2307) were shared between patient’s carriage and water system; underscoring the possible role of water system in cross-transmission of Pseudomonas [30]. Despite established evidence that P. aeruginosa contamination of wastewater systems such as toilets and shower sinks [31] might also serve as sources of infection, wastewater systems were not analysed for P. aeruginosa in this study.

Conclusions

To the best of our knowledge this is one of the largest studies on the prevalence of P. aeruginosa induced SSI in Africa. Post-discharge surveillance was effective due to the use of text message recalls. Although the rate of P. aeruginosa SSI was low, endogenous sources appeared to be a more probable source of transmission than the hospital water system. Multi-resistance of P. aeruginosa to clinically used antibiotics is an issue which needs to be taken into account.

Abbreviations

BMC: 

Bugando Medical Centre

DIN: 

Deutsches Institut für Normung (German Institute for Standardization)

EN: 

European Committee for Standardization

EUCAST: 

European Committee on Antimicrobial Susceptibility Testing

ISO: 

International Organization for Standardization

MLST: 

Multilocus sequence typing

NHSN: 

National Healthcare Safety Network

SSI: 

surgical site infection

ST: 

Sequence type

Declarations

Acknowledgements

The authors thank the technical assistance provided by Vitus Silago and Hezron Basu of the CUHAS microbiology laboratory. They are grateful to the key surveillance nurses from BMC hospital (Stella Rujwauka, Grace Ludovick, Maulidi Misanga, Tecla Tumsime and Paul Mvanda) as well as for nurses from SekouToure hospital (Pili Mbwana Kombo, Flora George Masanja and Anna Paul Lwanji), for their participation in this study.

Funding

This study was supported by funds from the Institute for Hygiene and Microbiology of Wuerzburg, Germany, CUHAS and German Academic Exchange Service (DAAD) to NM.

This publication was funded by the German Research Foundation (DFG) and the University of Wuerzburg in the funding programme Open Access Publishing.

Availability of data and materials

All data have been included in this manuscript.

Authors’ contributions

NM, HC, UV and SEM conceived the idea and designed the study. NM collected data. NM performed preliminary laboratory analysis. NM and HC performed molecular characterization of the isolates. HC, SEM, UVand NM analysed data. NM wrote the first draft of the manuscript which was reviewed and approved by UV, HC and SEM. All authors read and approved the final manuscript.

Competing interests

The authors declare that they have no competing interests.

Consent for publication

Not applicable.

Ethics approval and consent to participate

The Joint CUHAS/BMC research ethics and review committee approved the study protocol with clearance number CREC/019/2014. All patients signed an informed written consent.

Publisher’s Note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Open AccessThis article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.

Authors’ Affiliations

(1)
Institute for Hygiene and Microbiology, University of Wuerzburg
(2)
Department of Microbiology and Immunology, Catholic University of Health and Allied Sciences

References

  1. Bodey GP, Bolivar R, Fainstein V, Jadeja L. Infections caused by Pseudomonas aeruginosa. Rev Infect Dis. 1983;5:2.View ArticleGoogle Scholar
  2. Bert F, Maubec E, Bruneau B, Berry P, Lambert-Zechovsky N. Multi-resistant Pseudomonas aeruginosa outbreak associated with contaminated tap water in a neurosurgery intensive care unit. J Hosp Infect. 1998;39:1.View ArticleGoogle Scholar
  3. Ferroni A, Nguyen L, Pron B, Quesne G, Brusset M, Berche P: Outbreak of nosocomial urinary tract infections due to Pseudomonas aeruginosa in a paediatric surgical unit associated with tap-water contamination. J Hosp Infect 1998;39:4.Google Scholar
  4. Falkinham JO III, Hilborn ED, Arduino MJ, Pruden A, Edwards MA. Epidemiology and ecology of opportunistic premise plumbing pathogens: Legionella pneumophila, Mycobacterium avium, and Pseudomonas aeruginosa. Environ Health Perspect. 2015;123:8.Google Scholar
  5. Turner KH, Everett J, Trivedi U, Rumbaugh KP, Whiteley M. Requirements for Pseudomonas aeruginosa acute burn and chronic surgical wound infection. PLoS Genet. 2014;10:7.Google Scholar
  6. Loveday H, Wilson J, Kerr K, Pitchers R, Walker J, Browne J. Association between healthcare water systems and Pseudomonas aeruginosa infections: a rapid systematic review. J Hosp Infect. 2014;86:1.View ArticleGoogle Scholar
  7. Garvey MI, Bradley CW, Tracey J, Oppenheim B. Continued transmission of Pseudomonas aeruginosa from a wash hand basin tap in a critical care unit. J Hosp Infect. 2016;94:1.View ArticleGoogle Scholar
  8. Agodi A, Barchitta M, Cipresso R, Giaquinta L, Romeo MA, Denaro C. Pseudomonas aeruginosa carriage, colonization, and infection in ICU patients. Intensive Care Med. 2007;33:7.View ArticleGoogle Scholar
  9. Thuong M, Arvaniti K, Ruimy R, De la Salmoniere P, Scanvic-Hameg A, Lucet J, et al. Epidemiology of Pseudomonas aeruginosa and risk factors for carriage acquisition in an intensive care unit. J Hosp Infect. 2003;53:4.View ArticleGoogle Scholar
  10. Manyahi J, Matee MI, Majigo M, Moyo S, Mshana SE, Lyamuya EF. Predominance of multi-drug resistant bacterial pathogens causing surgical site infections in Muhimbili national hospital, Tanzania. BMC Res Notes. 2014;7:1.View ArticleGoogle Scholar
  11. Moremi N, Mushi MF, Fidelis M, Chalya P, Mirambo M, Mshana SE. Predominance of multi-resistant gram-negative bacteria colonizing chronic lower limb ulcers (CLLUs) at Bugando medical center. BMC Res Notes. 2014;7:1.View ArticleGoogle Scholar
  12. Nobert N, Moremi N, Seni J, Dass RM, Ngayomela IH, Mshana SE, et al. The effect of early versus delayed surgical debridement on the outcome of open long bone fractures at Bugando medical Centre, Mwanza, Tanzania. J Trauma Manag Outcomes. 2016;10:1.View ArticleGoogle Scholar
  13. Abbas M, Pittet D. Surgical site infection prevention: a global priority. J Hosp Infect. 2016;93:4.View ArticleGoogle Scholar
  14. Allegranzi B, Bischoff P, de Jonge S, Kubilay NZ, Zayed B, Gomes SM, et al. New WHO recommendations on preoperative measures for surgical site infection prevention: an evidence-based global perspective. Lancet Infect Dis. 2016;16:12.Google Scholar
  15. Horan TC, Andrus M, Dudeck MA. CDC/NHSN surveillance definition of health care–associated infection and criteria for specific types of infections in the acute care setting. Am J Infect Control. 2008;36:5.View ArticleGoogle Scholar
  16. Bertrand X, Thouverez M, Talon D, Boillot A, Capellier G, Floriot C, et al. Endemicity, molecular diversity and colonisation routes of Pseudomonas aeruginosa in intensive care units. Intensive Care Med. 2001;27:8.View ArticleGoogle Scholar
  17. DIN E: 19458: water quality- sampling for microbiological analysis ISO 19458: 2006).Google Scholar
  18. Habs H, Kirschner K. Der Pyocyaneus-Meerschweinchenhautversuch zur Prüfung von Hautdesinfektionsmitteln. Med Microbiol Immunol. 1942;124:5.Google Scholar
  19. Curran B, Jonas D, Grundmann H, Pitt T, Dowson CG. Development of a multilocus sequence typing scheme for the opportunistic pathogen Pseudomonas aeruginosa. J Clin Microbiol. 2004;42:12.View ArticleGoogle Scholar
  20. Pitout JD, Gregson DB, Poirel L, McClure J-A, Le P, Church DL. Detection of Pseudomonas aeruginosa-producing metallo-β-lactamases in a large centralized laboratory. J Clin Microbiol. 2005;43:7.Google Scholar
  21. Poirel L, Walsh TR, Cuvillier V, Nordmann P. Multiplex PCR for detection of acquired carbapenemase genes. Diagn Microbiol Infect Dis. 2011;70:1.View ArticleGoogle Scholar
  22. Kagan LJ, Aiello AE, Larson E. The role of the home environment in the transmission of infectious diseases. J Community Health. 2002;27:4.View ArticleGoogle Scholar
  23. Murthy SK, Baltch AL, Smith R, Desjardin E, Hammer M, Conroy J, et al. Oropharyngeal and fecal carriage of Pseudomonas aeruginosa in hospital patients. J Clin Microbiol. 1989;27:1.Google Scholar
  24. Glupczynski Y, Bogaerts P, Deplano A, Berhin C, Huang T-D, Van Eldere J, et al. Detection and characterization of class a extended-spectrum-β-lactamase-producing Pseudomonas aeruginosa isolates in Belgian hospitals. J Antimicrob Chemother. 2010;65:5.View ArticleGoogle Scholar
  25. Edelstein MV, Skleenova EN, Shevchenko OV, D'souza JW, Tapalski DV, Azizov IS, et al. Spread of extensively resistant VIM-2-positive ST235 Pseudomonas aeruginosa in Belarus, Kazakhstan, and Russia: a longitudinal epidemiological and clinical study. Lancet Infect Dis. 2013;13:10.View ArticleGoogle Scholar
  26. Yoo JS, Yang JW, Kim HM, Byeon J, Kim HS, Yoo JI, et al. Dissemination of genetically related IMP-6-producing multidrug-resistant Pseudomonas aeruginosa ST235 in South Korea. Int J Antimicrob Agents. 2012;39:4.View ArticleGoogle Scholar
  27. Kim MJ, Bae IK, Jeong SH, Kim SH, Song JH, Choi JY, et al. Dissemination of metallo-β-lactamase-producing Pseudomonas aeruginosa of sequence type 235 in Asian countries. J Antimicrob Chemother. 2013;68:12.View ArticleGoogle Scholar
  28. Libisch B, Watine J, Balogh B, Gacs M, Muzslay M, Szabó G, et al. Molecular typing indicates an important role for two international clonal complexes in dissemination of VIM-producing Pseudomonas aeruginosa clinical isolates in Hungary. Res Microbiol. 2008;159:3.View ArticleGoogle Scholar
  29. Correa A, Del Campo R, Perenguez M, Blanco VM, Rodríguez-Baños M, Perez F, et al. Dissemination of high-risk clones of extensively drug-resistant Pseudomonas aeruginosa in Colombia. Antimicrob Agents Chemother. 2015;59:4.View ArticleGoogle Scholar
  30. Rogues A-M, Boulestreau H, Lashéras A, Boyer A, Gruson D, Merle C, et al. Contribution of tap water to patient colonisation with Pseudomonas aeruginosa in a medical intensive care unit. J Hosp Infect. 2007;67:1.View ArticleGoogle Scholar
  31. Breathnach A, Cubbon M, Karunaharan R, Pope C, Planche T. Multidrug-resistant Pseudomonas aeruginosa outbreaks in two hospitals: association with contaminated hospital waste-water systems. J Hosp Infect. 2012;82:1.View ArticleGoogle Scholar

Copyright

© The Author(s). 2017

Advertisement