**4. Discussion**

other medical devices. 108(70.6% ) bacterial strains producing biofilms were isolated from patients having chronic infections eg persistent or recurrent UTI, Chronic obstructive airway

In our study the cut off OD(ODc) was 0.003. The biofilm forming organisms are grouped into weak group (OD ≥ 0.003 to 0.006), moderate group (OD ≥ 0.006 to 0.012) and strong

**producers Organisms**

**ESBL + MBL**

7 6 4 11 - - - 5

6 4 2 20 1 - - 1

3 2 1 8 2 - - 19

1 1 1 4 1 - - 2

1 - - - - - - -

1 1 2 - - - - -


**ESBL + AmpC**

P.aeruginosa [90] 10 14 10 23 - - - 33

E.coli [80] 10 7 4 38 1 - 1 19

Proteus species [5] 3 1 - 1 - - - -

**Table 1.** Incidence of strong biofilm producers amongst newer β – lactamases producing strains

It was observed that out of 57 newer β – lactamases (Extended spectrum β – lactamases i.e. ESBL, Amp C β – lactamases and Metallobetalactamases i.e. MBL only and in combination)

**Newer β – lactamases producers Non β –**

**AmpC + MBL** **ESBL + AmpC +MBL**

**lactamase**

disease, cystic fibrosis etc.

**ESBL Only** **AmpC Only**

**MBL Only**

group (OD > 0.012).

66 Infection Control

Strongly adherent biofilm producing P.aeruginosa

Strongly adherent biofilm producing

Strongly adherent biofilm producing K. pneumoniae

Strongly adherent biofilm producing Proteus species

Acinetobacter baumani [4]

Strongly adherent biofilm producing Acinetobacter baumani

E.coli

Klebsiella pneumonia [35]

> Our Hospital is a tertiary care centre in a rural setup. Though CLSM is the best phenotypic method, it could not be used as it is very costly. We did a pilot study with Staphylococci in 2008 and found 33% of Staphylococcus aureus and 44.7% of Coagulase Negative Staphylococci (CONS) were biofilm producers and amongst the 3 phenotypic methods tissue culture plate method gave the best results [58]. The present study correlated well with reports of other authors that Extended Spectrum β-Lactamase (ESBL) producing strains, Methicillin Resistant Staphylococcs aureus(MRSA) were more adherent to microtitre plate than Non ESBL and Non MRSA strains (Figure 2).

> Lee et al in 2008 have also reported a positive correlation between biofilm formation and ESBL producing Acinetobacter baumanii [59]. Norouzi et al in 2010 have reported that in their study 14% ESBL producing Pseudomonas aeruginosa has formed strongly adherent biofilm com‐ pared to only 4% of non-ESBL producing Pseudomonas aeruginosa [60]. It has also been

To prevent biofilm formation, the physical approaches like the use of low strength electrical field [68], electromagnetic field or ultrasound along with antibiotic therapy [69] are also very promising. A novel treatment based on disruption of quorum sensing system to inhibit biofilm formation has also been suggested by many workers [70]. Even the workers have suggested the inhibition of transcription of genes that are activated or repressed during initial biofilm formation will also help to prevent persistent infection due to biofilms. All these control strategies are on experimental basis and are not applicable for medical devices and have their

Biofilms: A Challenge to Medical Fraternity in Infection Control

http://dx.doi.org/10.5772/55649

69

To conclude, we must say biofilm develops slowly but has a major impact both clinically and economically on overall outcome of the patients treatment. The authors feel that, EARLY DETECTION AND NEWER TREATMENT OPTIONS FOR BIOFILM ASSOCIATED INFEC‐

, Monali N. Rajurkar, Ruchita O. Attal and Sanjay Kumar Mallick

[1] Doulam RM, Costerton JW. Biofilms: Survival mechanisms of clinically relevant mi‐

[2] Davis DG, Geesy GG. Regulation of the alginate biosynthesis gene algC in Pseudo‐ monas aeruginosa during biofilm development in continuous culture. Appl Environ

[3] Introduction to Biofilms: Negative and positive impacts of biofilm. Available from:

[4] Schopf JW, Hayes JM, Walter MR. Evolution on earth's earliest ecosystems: recent progress and unsolved problems. In: Schopf JW Ed, Earth's earliest biosphere.

[5] Jones DA, Amy PS. A thermodynamic interpretation of microbiologically influenced

[6] Toole GO, Kaplan HB, kolter R. Biofilm formation as microbial development. Annu

http://www.cs.montana.edu/ross/personal/intro-biofilms-s3.html.

Department of Microbiology, Jawaharlal Nehru Medical College, Wardha (M.S.), India

cro-organisms. Clin Microbiol Rev. 2002; 15(2): 167-193.

Princeton University Press, New Jersy, 1983; 15:143-147.

own limitations to be used cuurently in patients.

TIONS ARE NEED OF THE HOUR.

Microbiol. 1995; 61: 860-7.

corrosion. Corros2002;58:638-645.

Rev Microbiol.2000; 54:49-79.

**Author details**

Silpi Basak\*

**References**

**Figure 2.** Strogly adherent biofilm producing strains (%) amongst newer β – lactamase producers and non β – lacta‐ mase producers

reported that, biofilm production was higher amongst MRSA strains as compared to Metthi‐ cillin sensitive S.aureus (MSSA) strains [61].

### **5. Treatment and control strategies**

As far as the treatment of the persistant infection with medical device is concerned, the first step is to remove the infected indwelling medical device. Several control strategies have been proposed for biofilms e.g. systemic ciprofloxacin therapy in catheterized patients [1], latex catheter coated with silicone or silver hydrogel, catheter containing or use of antibiotics specially combination of Rifampicin and Minocyclin into material of indwelling catheters [62], Nitrofurazon coating, pretreatment of catheter surfaces with Furanones or Liposomes, Targetting the irradication of extra cellular polymeric biomolecules by enzymes [63] etc. Other strategies include disinfection of the insertion sites [64], surgical site irrigation, with biocides or antimicrobial locks to reduce indwelling catheter associated infections [65]. Cartin and Donlan have reported the ability of bacteriophage to degrade biofilm formation by Staphylo‐ coccus epidermidis [66]. Vejborg and Klemn have reported blocking of bacterial biofilm formation by a fish protein coating [67]. In dentistry, other than sodium hypochlorite irrigation, the newer techniques for biofilm eradication include ultrasonic irrigation, Ozone, plasma dental probe, photoactive disinfection with low energy LASER etc [32].

To prevent biofilm formation, the physical approaches like the use of low strength electrical field [68], electromagnetic field or ultrasound along with antibiotic therapy [69] are also very promising. A novel treatment based on disruption of quorum sensing system to inhibit biofilm formation has also been suggested by many workers [70]. Even the workers have suggested the inhibition of transcription of genes that are activated or repressed during initial biofilm formation will also help to prevent persistent infection due to biofilms. All these control strategies are on experimental basis and are not applicable for medical devices and have their own limitations to be used cuurently in patients.

To conclude, we must say biofilm develops slowly but has a major impact both clinically and economically on overall outcome of the patients treatment. The authors feel that, EARLY DETECTION AND NEWER TREATMENT OPTIONS FOR BIOFILM ASSOCIATED INFEC‐ TIONS ARE NEED OF THE HOUR.
