The spectrum of intraoral bacteria seen in patients with cleft palates in an African setting

Abstract Dehiscence or palatal fistula formation following palatoplasty is a complication that has grave consequences for the patient that include tissue loss, emotional distress to the parents and patient, and further medical costs. Palatal dehiscence or fistula formation is multifactorial following surgery—tension of wound closure, poor patient adherence to postoperative orders and wound infection are the most common causes for this. Oral colonization with pathogenic organisms could play a role in wound healing complications. Identification of intraoral bacteria among patients with cleft palates has thus far not been performed. To identify the spectrum of intraoral bacteria in cleft palate patients in an African setting; a retrospective, chart review was performed at Inkosi Albert Luthuli Central Hospital—a quaternary hospital in Durban, South Africa. All patients with unrepaired cleft palates who underwent palatoplasty in 2015 were included. Fifty‐two patients were included. Preoperative throat/palatal swabs were taken prior to palatoplasty. The various bacteria cultured from the aforementioned swabs were cataloged. Various bacteria were cultured. In total, 23 patients (44.2%) had positive swab cultures. Eighteen cultures (34.6%) had gram‐positive growth only, four cultures (7.7%) had gram‐negative growth only, while one patient (1.9%) cultured both a gram‐positive and a gram‐negative organism. Streptococcus viridans was the most commonly cultured organism (19.2%) while beta‐hemolytic streptococci were cultured from only 4 swabs (7.7%). Our study cataloged the commonly occurring bacteria found in unrepaired cleft palate patients in Africa. Further research into the clinical significance of each bacteria is advised.


RAMDIAL AnD MADAREE
Patients in our setting are not part of a homogenous group and come from various racial, cultural, ethnic and socioeconomic backgrounds; it is possible that they harbor bacteria different from those identified in studies from other regions. In light of this, we sought to identify the spectrum of intraoral bacteria in our local cleft palate population.

| MATERIAL S AND ME THODS
Inkosi Albert Luthuli Central Hospital (IALCH) in Durban, is a quaternary level hospital, which serves the province of Kwa-Zulu Natal in South Africa. Among its various disciplines is the Department of Plastic and Reconstructive Surgery which, among other services, provides comprehensive cleft care to those in need. Patients with cleft palates are referred to the IALCH Plastic Surgery clinic from a variety of primary, district and regional healthcare facilities.
The vast majority of the patients underwent a palatoplasty at nine months of age unless they were not fit for surgery or were referred late to the department. Patients were not prescribed antibiotics or any special diets leading up to surgery, and were given an admission date a day prior their operation. Patients were kept nil per os on the day of the surgery and no intraoral mouthwashes were administered.
In theater, the patients were intubated under sterile conditions and no intraoral irrigation was used. Cleaning of the patient was performed with a povidone-iodine solution and involved external surfaces only-no intraoral cleaning was performed. All operations were performed under sterile conditions with the surgeon, assistants and scrub sister in sterile gowns.
After the insertion of the Dingman retractor by the operating surgeon, an intraoral pus swab was taken with attention paid to the throat and palatal cleft. This pus swab was sent to the Microbiology laboratory for microscopy, culture and sensitivity testing. A prophylactic antibiotic (amoxicillin/clavulanic acid) was then administered intravenously. Palatoplasty was performed according to the departmental protocols. All patients were given oral analgesia and an antibiotic (amoxicillin/clavulanic acid) postoper-

| RE SULTS
Fifty-two patients underwent palatoplasty during the aforementioned timeframe. Thirty were male and 22 were female, with a maleto-female ratio of 1.36:1. The age range was between 8 months and 23 years. The majority of these patients (29 out of 52; 55.8%) were less than or equal to 18 months of age-the age below which palatoplasty is advised for optimal speech development (Goldstein et al., 2014;Ha et al., 2013). Twelve patients (23%) had complete cleft palates and 40 patients (77%) had incomplete cleft palates. (Table 1).
Twenty-three patients (44.2%) cultured organisms (single or multiple) from their intraoral pus swabs. Only three of these patients (5.8% of the entire cohort) cultured more than one organism. Single organism growth was present in 20 swabs (38.5%). Eighteen cultures (34.6%) had gram-positive growth only, four cultures (7.7%) had gram-negative growth only, while one patient (1.9%) cultured both a gram-positive and a gram-negative organism. Twenty-nine patients had clean (no growth) pus swabs (55.8%). (  Streptococci were the most common organisms cultured and found in 16 of the patients (30.8%). Of these, β-hemolytic streptococci were identified in four patients (7.7% of all patients). The most commonly cultured streptococcal organism in our cohort was Streptococcus viridans (19.2% of all patients). The next most commonly cultured organism was staphylococcus aureus (5 patients; 9.6% of all patients).
Although not considered as bacteria, yeasts were cultured in two patients (3.9%).

| D ISCUSS I ON
The human oral cavity serves as an entry point to the digestive tract and is a veritable zoo of microbes. Approximately, 700 different bacterial species have been identified in this area (Wang, 2013). There has been limited research conducted in Africa in this field (Mÿburgh & Bütow, 2009;Roode, Bütow, & Naidoo, 2017).
As mentioned earlier, dehiscence or palatal fistula formation following palatoplasty is a complication that has far-reaching consequences for the patient (Cocco et al., 2010). Palatal dehiscence or fistula formation is a multifactorial postoperative complication following surgery with wound infection being a major contributor (Deshpande et al., 2014;Hupkens et al., 2007;Zhang et al., 2014).
Palatal surgery can be defined as a clean/contaminated procedure as the surgical wound is an entry portal through which the microorganisms invade. There is a strong relationship between preoperative cultures and postoperative palatal dehiscence, particularly Group A Streptococcus and Staphylococcus aureus (Hupkens et al., 2007).
Of particular interest to surgeons is the presence of β-hemolytic streptococcus. Although all bacteria in levels greater than 10 5 organisms per gram of tissue can cause clinical infection, only β-hemolytic streptococci appear to be capable of routinely causing infection at levels of less than 10 5 or 100,000 organisms per gram of tissue (Franz, Steed, & Robson, 2007 Studies have shown a higher incidence of dental caries in patients with oral clefts compared to noncleft controls (Sundell, Ullbro, Marcusson, & Twetman, 2015). These patients frequently have poor oral hygiene, enamel hypoplasia, and early colonization of cariesinducing microorganisms. In their study, Sundell et al. (2015), collected saliva samples from patients with and without oral clefts.
They noted that oral hygiene may be impaired in the cleft population owing to many factors-fear of brushing around the cleft area, the anatomy of the cleft itself, restricted access for tooth brushing and a higher incidence of misaligned teeth. They were unable to demonstrate an increase in Streptococcus mutans; however, the cleft group Older child would thus have more Streptococcal species as they are able to consume a wider variety of sugary foods (Arief, Mohamed, & Idris, 2005).
Our study results differ from many of the aforementioned studies in that a number of our patients cultured gram-negative organisms.
This could be that other studies did not test for these organisms, or the results were discarded, as they were not part of the study objectives. Nonetheless, the significance of gram-negative organisms in our cohort is uncertain. Further evaluation into wound healing and postoperative complications among these patients is needed.
It is interesting to note that 39.1% of patients who cultured pos- Our study has limitations. The large number of patients (55.8%) who did not culture organisms from their pus swabs is of concern.
This could be due to sampling errors-the swabs focused on the throat and palate. Perhaps more comprehensive swabbing of the oral cavity may yield more positive swabs. Another possibility is that the Microbiology laboratory may not report on oral commensals, which are cultured. Pus swabs themselves may have lower bacterial yields than tissue biopsies; however, we did not feel this was justified in light of the potential morbidity.
There is room for further study. Although β-hemolytic streptococci have the potential to cause serious tissue injury, their role in cleft palate surgery remains uncertain. A link between these organisms and postoperative palatal dehiscence and fistula formation should be sought. Similarly, the role of gram-negative bacteria should be investigated. The role of rapid detection systems for Group A Streptococcus has been validated (Gazzano et al., 2016;Hudson, Theron, Roditi, & Bloch, 1991;Wang et al., 2017) and we feel there could be a role for such kits in cleft palate surgery.

| CON CLUS ION
Our study has added to the body of knowledge concerning the spectrum of intraoral bacteria among cleft palate patients in an African setting. The significance of each organism will require further study.
Identifying pathogenic organisms preoperatively could potentially lead to better cleft palate repair results.

CO N FLI C T O F I NTE R E S T
None declared.