**6. Diseases due to biofilm**

Besides infecting the industrial pipelines, waste water channels, oral cavity, ventilators, catheters, and medical implants, they are a major cause of human diseases [11]. Infections and diseases in humans are mostly due to development of biofilm on or within indwelling implants or devices such as contact lenses, bio prosthetic and mechanical heart valves, pacemakers, intra-arterial and intravenous catheters, central venous catheters, peritoneal dialysis catheters, urinary catheters, joint prosthesis, voice prosthesis, penile prosthesis, ureteral stents, biliary stents, endotracheal tubes, nephrostomy tubes, intrauterine contraceptive devices (IUDs) [13, 14]. A biofilm may be composed of gram-positive or gram-negative microorganisms which may arise from the skin of a patient, health worker, tap water or any other environmental source [5].

Biofilm growth usually was seen in the lungs of cystic fibrosis patients causing chronic bronchopneumonia, in the middle ear in patients with chronic and secretory otitis media, in chronic rhino sinusitis, in chronic osteomyelitis and in chronic

**155**

**Table 1.**

*Microbial Biofilms*

*DOI: http://dx.doi.org/10.5772/intechopen.90790*

wounds [15]. Infections and then diseases occur because of these two reasons: (a) Implantation of any medical device cause tissue damage which attracts platelets and fibrin accumulation at the site of the attachment. The damaged tissue aids in colonizing the microorganisms [13]. (b) Drug resistance and inflammation in host might get stimulated by biofilm formation which results in sustained infections [16] (**Table 1**).

**Gram-positive microorganisms Site of infections and diseases**

arteriovenous shunts

IUDs

**diseases**

prostatitis

Gram-positive cocci (e.g. *Staphylococci*) Musculoskeletal infections Group A *Streptococci* Necrotizing fasciitis Viridans Group *Streptococci* Native valve endocarditis *S. epidermidis* and *S. aureus* Sutures, exit sites and

*S. epidermidis, E. faecalis* Urinary catheter cystitis

**Gram-negative microorganisms The site of infections and** 

*E. coli* (enteric bacteria) Biliary tract infection, bacterial

*P. aeruginosa and Burkholderia cepacia* Cystic fibrosis pneumonia *Pseudomonas pseudomallei* Melioidosis nosocomial infections

*Klebsiella pneumoniae, Proteus mirabilis* Urinary catheter cystitis *K. pneumoniae, P. aeruginosa* Central venous catheter *Proteus mirabilis, Bacteroides* species, *P. aeruginosa, E. coli* Orthopedic devices

Nontypable strains of *Haemophilus influenzae* Otitis media

*C. albicans, S. epidermidis* Hickman catheter *S. epidermidis, S. aureus, E. faecalis, C. albicans* Central venous catheter *Viridans Streptococci, Enterococci* Mechanical heart valves *Hemolytic Streptococci, Enterococci* Orthopedic devices *S. epidermidis, S. aureus,* Penile prosthesis

Acidogenic gram-positive cocci (e.g. *Streptococcus*) Dental caries

*S. epidermidis, S. aureus, Corynebacterium* species, *Micrococcus* species,

*Enterococcus* species, *Candida albicans,* Group B *Streptococci*

Commonly found organisms on catheter biofilm are *S. epidermidis, S. aureus, K. pneumoniae, C. albicans, P. aeruginosa,* and *E. faecalis.* These might get emerged from patient's skin microflora, exogenous microflora from health-care personnel, or infected infusates. It has been reported that inner lumen of long-term catheters (30 days) and an external surface of short-term catheters (<10 days) has more biofilm formation. Microbial growth may depend on the nature of fluid delivered through a central venous catheter, as it has been seen that gram-negative microorganisms grow well in the intravenous fluid than gram-positive organisms [17].

**7. Biofilm on some common medical devices**

**7.1 Central venous catheter biofilms**

*Different infections and involved microorganisms [11].*

*Bacterial Biofilms*

form biofilm [2].

**5.6 Environmental factors**

*5.6.2 Presence of oxygen*

*5.6.3 Environmental pH*

where urine pH is acidic.

**6. Diseases due to biofilm**

other environmental source [5].

*5.6.4 Temperature*

substrate surface.

*5.6.1 Availability of certain nutrients*

ence of carbohydrates mannose and trehalose.

by impeding the mass transport of antibiotics through the biofilm, which might be by binding directly to these agents [1]. EPS formation is an essential part of biofilm formation as studies on *Staphylococcus epidermidis* have shown that if genes responsible for the synthesis of EPS matrix are inactivated then bacteria lose the ability to

Different environmental factors affect the biofilm formation; listed below:

It has been shown by studies on *Listeria monocytogenes* that an optimum level of phosphate is very important for biofilm formation and gets stimulated by the pres-

Presence of oxygen regulates Biofilm formation in *Escherichia coli*. In the absence of sufficient oxygen supply biofilm does not form as bacteria could not adhere to the

On the other hand, bacteria like *S. epidermidis* and *E. coli* do not need an alkaline environment for multiplying hence they easily form a biofilm on urethral catheters

When temperature was kept high, *L. monocytogenes* did not form biofilm as the

Besides infecting the industrial pipelines, waste water channels, oral cavity, ventilators, catheters, and medical implants, they are a major cause of human diseases [11]. Infections and diseases in humans are mostly due to development of biofilm on or within indwelling implants or devices such as contact lenses, bio prosthetic and mechanical heart valves, pacemakers, intra-arterial and intravenous catheters, central venous catheters, peritoneal dialysis catheters, urinary catheters, joint prosthesis, voice prosthesis, penile prosthesis, ureteral stents, biliary stents, endotracheal tubes, nephrostomy tubes, intrauterine contraceptive devices (IUDs) [13, 14]. A biofilm may be composed of gram-positive or gram-negative microorganisms which may arise from the skin of a patient, health worker, tap water or any

Biofilm growth usually was seen in the lungs of cystic fibrosis patients causing chronic bronchopneumonia, in the middle ear in patients with chronic and secretory otitis media, in chronic rhino sinusitis, in chronic osteomyelitis and in chronic

Environmental pH effects were observed by studying on *Vibrio cholerae*. Optimal pH for multiplication of *V. cholerae* is 8.2 and below pH 7 i.e., in acidic envi-

ronment the bacteria lose their ability to form biofilm as they lose mobility.

bacteria wasn't able to adhere itself to the substrate surface [2].

**154**


**Table 1.**

*Different infections and involved microorganisms [11].*

wounds [15]. Infections and then diseases occur because of these two reasons: (a) Implantation of any medical device cause tissue damage which attracts platelets and fibrin accumulation at the site of the attachment. The damaged tissue aids in colonizing the microorganisms [13]. (b) Drug resistance and inflammation in host might get stimulated by biofilm formation which results in sustained infections [16] (**Table 1**).
